Insecticidal Activities and GC-MS Analysis of the Selected Family Members of Meliaceae Used Traditionally as Insecticides

Abstract

The environmental and health risks associated with synthetic pesticides have increased the demand for botanical insecticides as safer and biodegradable alternatives to control insect pests in agriculture. Hence in this study, five Meliaceae species were evaluated for their insecticidal activities against the Spodoptera frugiperda and the Plutella xylostella larvae, as well as their chemical constituents. Repellence, feeding deterrence, and topical application bioassays were employed to evaluate their insecticidal activities. GC-MS analysis was performed to identify chemical compounds present in each plant. The repellence bioassay indicated that Melia azedarach extracts exhibited the highest repellence percentage against S. frugiperda (95%) and P. xylostella (90%). The feeding deterrence bioassay showed that M. azedarach and Trichilia dregeana extracts displayed excellent antifeeding activity against the S. frugiperda (deterrent coefficient, 83.95) and P. xylostella (deterrent coefficient, 112.25), respectively. The topical application bioassay demonstrated that Ekebergia capensis extracts had the highest larval mortality against S. frugiperda (LD₅₀ 0.14 mg/kg). Conversely, M. azedarach extracts showed the highest larval mortality against P. xylostella (LD₅₀ 0.14 mg/kg). GC-MS analysis revealed that all plant extracts had compounds belonging to the two noteworthy groups (phenols and terpenes), which possess insecticidal properties. Overall, this study lends scientific credence to the folkloric use of Meliaceae species as potential biocontrol agents against insect pests.

1. Introduction

The agricultural sector has always been faced with challenges due to insect pests and will continue to do so in the future [1]. These pests damage crops during the growing period, and they may also subsequently cause damage to the harvested products stored in storehouses [2]. Controlling insect pests remains a problem as the insects keep building resistance to common pesticides while, on the other hand, toxic pesticides are being removed from the markets [1]. Synthetic pesticides have been commonly used and are considered a highly effective means of controlling plant damage caused by insects [3], which leads to remarkable improvements in plant yield productivity [4]. However, the indiscriminate and haphazard usage of synthetic pesticides has adversely affected human health and the ecosystem as a whole [5].

The presence of pesticide residues in foods, fruits, vegetables, and even in breast-feeding mothers’ milk creates a threat to human health. In developing countries, nearly 3 million farmworkers experience severe pesticide poisoning, resulting in about 18,000 deaths, while 25 million workers suffer from mild pesticide poisoning each year [6]. The use of synthetic pesticides also raises several environmental concerns because over 5% of the sprayed synthetic pesticides do not reach their target insect pests; instead, they can be found in air, soil, and water streams [7]. As a result of these devastating occupational synthetic pesticide poisoning cases, research to find alternative methods that are environmentally friendly and cost-effective in controlling insect pests has increased [1].

Based on recent studies to find ways to mitigate problems caused by synthetic pesticides, natural bio-insecticides from medicinal plants can be an excellent alternative strategy to overcome pest resistance and environmental contamination [8]. This possibility is not surprising as plants are rich sources of bioactive chemicals, and botanical insecticides have been reported to have fewer adverse effects on the environment or human health [1].

Meliaceae is one of two flowering plant families that have gained considerable attention, whereby systematic investigations of its members for their insecticidal potential have been undertaken [9,10]. Chemicals extracted from members of the Meliaceae have received attention recently from applied entomologists due to their excellent properties as control agents for insects [11]. This knowledge has prompted the interest to assess other family members for their insecticidal and antifeedant properties in this study.

Plutella xylostella (L.) (Lepidoptera: Plutellidae), commonly known as the diamondback moth (DBM) or the cabbage moth, is an economically important pest of cruciferous plants globally [12]. The Diamondback moth is an oligophagous insect that mainly feeds on cole crops, including broccoli, brussels sprouts, canola, cauliflower, and cabbage, which are of essential economic value [13]. The insect is important in agriculture as causes yield losses of as much as 100% [14]. In the 1970s, there was a major outbreak of DBM, mainly due to the development of resistance to synthetic insecticides [13]. It has been estimated that the yield losses and control associated with diamondback moth globally ranged between 4–5 US billion dollars yearly [14]. In sub-Saharan Africa, crop losses due to diamondback moths have been reported to be between 8–22% in the field [15].

Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), commonly known as the fall armyworm (FAW), is a polyphagous insect that is important in agriculture as it is difficult to control and, as a result, causes a lot of damage [16]. This migratory insect also causes enormous economic losses, mainly attacking crops that form part of the primary staple food [17], including rice, maize, forage grasses, sorghum, alfalfa, vegetable crops, and many others [16]. The first case to be reported in Africa of the fall armyworm was in late 2016, when it attacked most West African farms and subsequently spread throughout the continent rapidly and is now found in 44 African countries [18]. Environmentally friendly and effective methods to control fall armyworms are crucial as these insects are heavy foliage feeders [17] and can result in the total loss of crops. In sub-Saharan Africa, maize, rice, sorghum, and sugarcane crop damage is estimated to cause up to USD 13 billion yearly [19].

Ever since plant-derived products have gained increased attention from researchers to assess their insecticidal properties, more than 2000 plant species have been recorded to be used traditionally as insecticides [20]. However, many studies that attempted to validate these properties scientifically are incomplete; the bioassays procedures used were usually inappropriate or inadequate [21]. As a result, biological compounds that are potentially useful remain uninvestigated, undiscovered, underutilized, or undeveloped from this reservoir of unstudied plant materials [22]. Hence, in this study, four Meliaceae species that had previously not been evaluated extensively for their insecticidal and antifeedant properties against the test insects S. frugiperda and P. xylostella were selected. Melia azedarach was chosen as a positive control as it is a well-known bioinsecticide plant. Water extracts were selected for extraction in this study because it is one of the simplest and safest (non-toxicity) solvents. In addition, aqueous plant extracts are traditionally used to control insect pests. Using aqueous extracts is fitting because the main purpose of this study is to identify safer, cost-effective, and renewable alternative methods to synthetic pesticides. Slightly polar acetone and ethanol extracts were selected because the main targeted compounds, limonoids (terpenes), were reported to have a higher solubility in polar solvents and alcohol [23].

2. Results

2.1. Antifeedant and Insecticidal Analysis

2.1.1. Repellence Test

Repellence Bioassay against S. frugiperda Larvae

Table 1. Average repellence of five Meliaceae species leaf extracts against Spodoptera frugiperda larvae using the treated filter paper test.

Plant Species	Extract	Dose/ Concentration (%)	Percentage Repulsion (PR) = 2 × (C − 50) in Hours C = Is the Percentage of Insects on the Untreated Half of the Disk				Average (PR)	Class
			1 H	2 H	3 H	4 H
1. Ekebergia capensis Sparrm	Aqueous	0.5	60	60	0	100	33	II
		1.0	−20	20	20	20
	Acetone	0.5	−20	20	20	20	15	I
		1.0	20	20	60	−20
	Ethanol	0.5	60	20	20	20	10	I
		1.0	−60	−20	20	20
2. Melia azedarach L.	Aqueous	0.5	100	100	100	100	95	V
		1.0	100	60	100	100
	Acetone	0.5	20	60	0	0	28	II
		1.0	60	−20	100	0
	Ethanol	0.5	20	100	20	20	65	IV
		1.0	100	100	60	100
3. Trichilia dregeana Harv. & Sond.	Aqueous	0.5	20	20	20	20	40	II
		1.0	20	60	60	100
	Acetone	0.5	60	60	50	0	71	IV
		1.0	100	100	100	100
	Ethanol	0.5	100	60	−60	−60	30	II
		1.0	20	60	60	60
4. Turraea floribunda Hochst.	Aqueous	0.5	−60	100	100	100	49	III
		1.0	0	100	0	50
	Acetone	0.5	60	60	20	100	20	I
		1.0	100	−100	−60	−20
	Ethanol	0.5	−60	−100	−60	−100	−55	-
		1.0	−60	−60	20	−20
5. Turraea obtusifolia Hochst.	Aqueous	0.5	0	0	5	0	3	I
		1.0	−20	−20	20	20
	Acetone	0.5	60	−20	60	−20	5	I
		1.0	−20	−20	−20	20
	Ethanol	0.5	−20	20	20	20	30	II
		1.0	20	60	60	60

indicates the results of the repellence bioassay test of the five selected Meliaceae species against the S. frugiperda. Positive average percentage repulsion values exhibit repellence, and negative average percentage repulsion values exhibit attractancy. Plant extracts that are ranked in higher classes (i.e., III, IV, and V) are considered to have a high repellence against the larvae, and those that are ranked to lower classes (I and II) have partial repellence against the larvae. Aqueous and ethanolic extracts of Melia azedarach L. and Trichilia dregeana Harv. & Sond. acetone extracts were found to have strongly repelled the S. frugiperda larvae with repellence of 95%, 65%, and 71%, and they belonged to class V, IV, and IV, respectively. It is followed by aqueous extracts of Turraea floribunda Hochst. (49%) belonging to class III. Aqueous and ethanol extracts of T. dregeana and ethanolic extracts of Turraea obtusifolia Hochst. moderately repelled the S. frugiperda with repellence of 40%, 30%, and 30%, respectively. Aqueous and acetone extracts of T. obtusifolia were recorded to have the lowest repellency (3% and 5%) and were all assigned to the lowest class (I). Ethanolic extracts of T. floribunda (−55%) indicated S. frugiperda larvae stimulation.

Repellence Bioassay against P. xylostella Larvae

Table 2. Average repellence of five Meliaceae species leaf extracts against Plutella xylostella larvae using the treated filter paper test.

Plant Species	Extract	Dose/ Concentration (%)	Percentage Repulsion (PR) = 2 × (C − 50) in Hours C = Is the Percentage of Insects on the Untreated Half of the Disk				Average (PR)	Class
			1 h	2 h	3 h	4 h
1. Ekebergia capensis	Aqueous	0.5	60	60	100	100	60	III
		1.0	−20	20	60	100
	Acetone	0.5	−20	20	60	100	50	III
		1.0	20	20	100	100
	Ethanol	0.5	60	20	100	100	50	III
		1.0	−60	−20	100	100
2. Melia azedarach	Aqueous	0.5	100	100	100	100	90	V
		1.0	100	60	100	60
	Acetone	0.5	20	60	20	20	35	II
		1.0	60	−20	60	60
	Ethanol	0.5	20	100	100	60	80	IV
		1.0	100	100	100	60
3. Trichilia dregeana	Aqueous	0.5	20	20	60	60	45	III
		1.0	20	60	60	60
	Acetone	0.5	60	60	60	20	65	IV
		1.0	100	100	60	60
	Ethanol	0.5	100	60	100	60	65	IV
		1.0	20	60	60	60
4. Turraea floribunda	Aqueous	0.5	−60	100	20	60	43	III
		1.0	0	100	100	20
	Acetone	0.5	60	60	20	60	30	II
		1.0	100	−100	20	20
	Ethanol	0.5	−60	−100	60	60	−10	-
		1.0	−60	−60	20	60
5. Turraea obtusifolia	Aqueous	0.5	0	0	60	60	15	I
		1.0	−20	−20	20	20
	Acetone	0.5	60	−20	20	60	30	II
		1.0	−20	−20	60	100
	Ethanol	0.5	20	−60	60	100	31	II
		1.0	60	−50	20	100

indicates the average percentage repulsion for the five Meliaceae species screened for their repellence activity against P. xylostella larvae. The overall highest percentage repulsion against the P. xylostella larvae was recorded for the aqueous (90%) and ethanol (80%) extracts of Melia azedarach, meaning that they exhibited excellent repellent activity, hence they were assigned to classes V and IV, respectively. Good repellent activity against P. xylostella was also recorded for acetone (65%) and ethanol (65%) extracts of T. dregeana, and they were assigned to class IV. Extracts of E. capensis moderately repelled P. xylostella larvae with repellence of 60% (aqueous), 50% (acetone), and 50% (ethanol), assigned to class III. All extracts of T. obtusifolia, i.e., aqueous (15%), acetone (30%), and ethanol (31%), recorded the lowest repellent activities against P. xylostella. Ethanolic extracts of T. floribunda (−10%) indicated the P. xylostella larvae stimulation.

2.1.2. Feeding Deterrence Test

Feeding Deterrence Activity of S. frugiperda Larvae

Table 3. Feeding deterrent activity coefficient of five Meliaceae species leaf extracts against Spodoptera frugiperda.

Plant Species	Extract	Coefficient of Deterrence			Efficacy of Extracts
		Absolute (A)	Relative (R)	Total (T)
1. Ekebergia capensis	Aqueous	21.66	26.61	48.27	+
	Acetone	25.14	19.97	45.11	+
	Ethanol	−10.77	28.55	17.78	+
2. Melia azedarach	Aqueous	48.04	35.88	83.92	++
	Acetone	58.14	3.43	61.57	++
	Ethanol	28.96	8.39	37.35	+
3. Trichilia dregeana	Aqueous	29.95	32.07	62.02	++
	Acetone	29.01	23.84	52.85	++
	Ethanol	14.30	31.99	46.29	+
4. Turraea floribunda	Aqueous	24.40	42.56	66.96	++
	Acetone	17.86	3.04	20.90	+
	Ethanol	3.04	−15.93	−12.89	0
5. Turraea obtusifolia	Aqueous	40.91	26.38	67.29	++
	Acetone	17.51	17.17	34.65	+
	Ethanol	27.06	41.38	68.44	++

indicates the feeding deterrent activity coefficients of Meliaceae species against the fall armyworm larvae. All extracts exhibited feeding activity against the larvae to a certain extent, except for the ethanolic extracts of T. floribunda, which were found to have inert antifeedant compounds against the S. frugiperda larvae with a feeding deterrent coefficient of −12.89. Of all the tested extracts, aqueous extracts of M. azedarach (83.92) and aqueous (68.44) and ethanol (67.29) extracts T. obtusifolia recorded the highest coefficient of deterrence, indicating a good feeding deterrence activity. Aqueous extracts of T. floribunda and aqueous extracts of T. dregeana moderately caused larvae fertility, with feeding deterrence coefficients of 66.96 and 62.02, respectively, ranked ++. Furthermore, ethanolic extracts of E. capensis and acetone extracts of T. floribunda were the least effective feeding deterrents against the S. frugiperda larvae.

Feeding Deterrence Activity of P. xylostella Larvae

Table 4. Feeding deterrent activity coefficient of five Meliaceae species leaves extracts against Plutella xylostella larvae.

Plant Species	Extract	Coefficient of Deterrence			Efficacy of Extract
		Absolute (A)	Relative (R)	Total (T)
1. Ekebergia capensis	Aqueous	27.65	3.61	31.26	+
	Acetone	50.60	2.57	53.17	++
	Ethanol	40.39	45.40	85.79	++
2. Melia azedarach	Aqueous	34.79	3.34	38.13	+
	Acetone	32.89	13.55	46.44	+
	Ethanol	56.13	4.13	60.26	++
3. Trichilia dregeana	Aqueous	45.85	52.92	98.77	++
	Acetone	62.37	49.88	112.25	+++
	Ethanol	63.52	35.87	99.39	++
4. Turraea floribunda	Aqueous	34.70	−20.75	13.95	+
	Acetone	49.41	−23.48	25.93	+
	Ethanol	49.65	−5.43	44.22	+
5. Turraea obtusifolia	Aqueous	42.24	44.50	86.74	++
	Acetone	38.94	0.94	39.88	+
	Ethanol	55.43	−1.06	54.37	++

indicates the feeding deterrent activities of the studied Meliaceae species against the diamondback moth larvae. All plant extracts exhibited noteworthy deterrence against the P. xylostella larvae. All extracts of T. dregeana showed exceptionally high feeding deterrent activities, with acetone recording a 112.25 deterrence coefficient ranked +++, ethanol (99.39, ++), and aqueous (98.77, ++). Aqueous extracts of T. obtusifolia and ethanolic extracts of E. capensis moderately caused feeding deterrence of the larvae, with feeding coefficients of 86.74 and 85.79, respectively, both ranked ++. Meanwhile, aqueous (13.95, +) and acetone (25.93, +) extracts of T. floribunda were the least effective feeding deterrents against P. xylostella larvae.

2.1.3. Topical Application Test

Contact Toxicity against S. frugiperda Larvae

Table 5. Toxicity of five Meliaceae species leaf extracts applied topically to Spodoptera frugiperda larvae.

Plant Species	Extracts	Concentration (ppm)	log10 (Concentration)	% Dead	Probit	LD50 (mg/kg)
Ekebergia capensis	Aqueous	500	2.70	80	5.84	0.14
		1000	3.00	80	5.84
	Acetone	500	2.70	80	5.84	707.95
		1000	3.00	20	4.16
	Ethanol	500	2.70	20	4.16	851.14
		1000	3.00	60	5.25
2. Melia azedarach	Aqueous	500	2.70	20	4.16	707.95
		1000	3.00	80	5.84
	Acetone	500	2.70	80	5.84	707.95
		1000	3.00	20	4.16
	Ethanol	500	2.70	80	5.84	707.95
		1000	3.00	20	4.16
3. Trichilia dregeana	Aqueous	500	2.70	20	4.16	707.95
		1000	3.00	80	5.84
	Acetone	500	2.70	60	5.25	707.95
		1000	3.00	40	4.75
	Ethanol	500	2.70	40	4.75	588.84
		1000	3.00	80	5.84
4. Turraea floribunda	Aqueous	500	2.70	60	5.25	0.56
		1000	3.00	60	5.25
	Acetone	500	2.70	80	5.84	707.95
		1000	3.00	20	4.16
	Ethanol	500	2.70	20	4.16	6.92
		1000	3.00	20	4.16
5. Turraea obtusifolia	Aqueous	500	2.70	60	5.25	371.54
		1000	3.00	80	5.84
	Acetone	500	2.70	40	4.75	707.95
		1000	3.00	60	5.25
	Ethanol	500	2.70	60	5.25	371.54
		1000	3.00	80	5.84

shows the direct contact toxicity of the Meliaceae plant extracts to the S. frugiperda larvae using different concentrations. Aqueous extracts of T. dregeana and M. azedarach exhibited a positive correlation, where the least concentrated extracts [0.5] showed less toxicity than the more concentrated extracts [1.0]. At [0.5], extracts recorded a 20% mortality rate, while [1.0] recorded an 80% mortality rate. The negative correlation between the concentration of extracts and the rate of mortality observed was recorded for E. capensis (acetone), M. azedarach (acetone and ethanol), and T. floribunda (acetone), where at [0.5] 20%, the mortality rate and at [1.0] mortality rate was 80%. Extracts that did not show any correlation and had constant mortality rates were aqueous extracts of E. capensis where, at [0.5] and [1.0], 80% of the larvae died, aqueous extracts of T. floribunda at [0.5] and [1.0] caused 60% mortality, and ethanolic extracts of T. floribunda at [0.5] and [1.0] caused 20% larval mortality. Probability unit (Probit) analysis showed that aqueous extracts of E. capensis (LD₅₀ value of 0.14 mg/kg) and T. floribunda (LD₅₀ value of 0.56 mg/kg) were more toxic to the S. frugiperda larvae. Probit analysis also indicated that ethanolic extracts of E. capensis were the least toxic to the fall armyworm, with LD₅₀ values of 851.14 mg/kg.

Contact Toxicity against P. xylostella Larvae

Results of the direct contact toxicity of the Meliaceae plant extracts to the P. xylostella larvae using different concentrations are outlined in

Table 6. Toxicity of five Meliaceae species leaf extracts applied topically to Plutella xylostella larvae.

Plant Species	Extracts	Concentration (ppm)	log10 (Concentration)	% Dead	Probit	LD50 (mg/kg)
1. Ekebergia capensis	Aqueous	500	2.70	40	4.75	691.83
		1000	3.00	60	5.25
	Acetone	500	2.70	20	4.16	707.95
		1000	3.00	80	5.84
	Ethanol	500	2.70	40	4.75	691.83
		1000	3.00	60	5.25
2. Melia azedarach	Aqueous	500	2.70	80	5.84	0.14
		1000	3.00	80	5.84
	Acetone	500	2.70	80	5.84	0.14
		1000	3.00	80	5.84
	Ethanol	500	2.70	80	5.84	0.14
		1000	3.00	80	5.84
3. Trichilia dregeana	Aqueous	500	2.70	40	4.75	691.83
		1000	3.00	60	5.25
	Acetone	500	2.70	80	5.84	707.95
		1000	3.00	20	4.16
	Ethanol	500	2.70	60	5.25	691.83
		1000	3.00	40	4.75
4. Turraea floribunda	Aqueous	500	2.70	80	5.84	851.14
		1000	3.00	40	4.75
	Acetone	500	2.70	20	4.16	851.14
		1000	3.00	60	5.25
	Ethanol	500	2.70	20	4.16	707.95
		1000	3.00	80	5.84
5. Turraea obtusifolia	Aqueous	500	2.70	40	4.75	1.78
		1000	3.00	40	4.75
	Acetone	500	2.70	20	4.16	1318.26
		1000	3.00	40	4.75
	Ethanol	500	2.70	80	5.84	1318.26
		1000	3.00	60	5.25

. All extracts of M. azedarach at 500 ppm and 1000 ppm concentrations showed excellent results, as they killed 80% of the P. xylostella larvae. The Probit analysis further supported this and indicated that all three different extracts of M. azedarach were the most toxic to P. xylostella, with LD₅₀ of 0.14 mg/kg. Results for acetone extracts of E. capensis and ethanolic extracts of T. floribunda showed a positive correlation between the concentration of extracts and mortality rates recorded. At [0.5], E. capensis and T. floribunda recorded a mortality of 20%, and at [1.0], they recorded an 80% mortality rate. The negative correlation between the concentration of extracts and the rate of mortality observed was recorded for acetone extracts of T. dregeana and aqueous extracts of T. floribunda. At [0.5], both extracts killed 80% of the larvae; at [1.0], T. dregeana killed 20%, while T. floribunda killed 40% of the larvae. Extracts that did not show any correlation and had a constant mortality rate were aqueous extracts of T. obtusifolia because, at [0.5] and [1.0], the extracts killed 40% of the P. xylostella larvae. Probit analysis indicated that only the aqueous extract of T. obtusifolia was the second most toxic to the P. xylostella larvae, with an LD₅₀ value of 1.78 mg/kg. Meanwhile, all other plant extracts displayed insignificant toxicity to the P. xylostella, with acetone and ethanol extracts of T. obtusifolia recording the highest LD₅₀ value of 1318.26 mg/kg.

2.2. GC-HRT-MS Analyses

The presence of chemical compounds in plants is important as they may be responsible for their biological activities, antifeedant and insecticidal properties.

Table 7. Compounds identified in leaf acetone extracts of Ekebergia capensis.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 13.95	218.9578	C15H24O	(1R,3E,7E,11R)-1,5,5,8-Tetramethyl-12-oxabicyclo[9.1.0]dodeca-3,7-diene	Epoxide	26,6925.50
2. 29.96	263.8374	C13H20N2SSi	1,2-Benzisothiazol-3-amine, TBDMS derivative	Sugar	18,674.71
3. 13.45	202.1718	C15H22	1,8-Cyclopentadecadiyne	Sesquiterpenoid	115,106.00
4. 12.71	180.1142	C11H16O2	2(4H)-Benzofuranone, 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-	Benzofuran	132,297.50
5. 16.78	165.1639	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	204,579.33
6. 30.25	326.7937	C24H36O2Si2	4-Methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene, 2TMS derivative	Bisphenol A	25,467.00
7. 18.36	218.9095	C20H40	5-Eicosene, (E)-	Aliphatic hydrocarbon	70,769.00
8. 21.85	218.9260	C18H35NO	9-Octadecenamide, (Z)-	Fatty amide	448,270.50
9. 20.26	130.9614	C11H16FNO3	Benzeneethanamine, 2-fluoro-β,3,4-trihydroxy-N-isopropyl-	Organofluorine compound	173,648.67
10. 24.10	130.9736	C39H28O4	Bis[2-(cinnamoyloxy)-1-naphthyl]methane		10,127.50
11. 13.56	218.9391	C15H24O	Caryophyllene oxide	Sesquiterpenoid	411,365.67
12. 27.33	394.3601	C27H44O	Cholesta-4,6-dien-3-ol, (3β)-	Cholesterol	108,829.33
13. 28.04	218.9138	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	24,262.25
14. 22.87	155.1795	C27H56	Heptacosane	Alkane	215,283.20
15. 13.54	218.8042	C16H34	Hexadecane	Alkane	729,031.09
16. 2.59	32.0408	H4N2	Hydrazine	Non-metal compound	12,709.83
17. 29.62	426.3880	C30H50O	Lupeol	Triterpenoid	84,095.50
18. 2.96	32.0260	CH4O	Methyl Alcohol	Alcohol	2773,625.86
19. 18.18	256.2399	C16H32O2	n-Hexadecanoic acid	Fatty acid	829,242.33
20. 16.70	218.9267	C20H38	Neophytadiene	Diterpenoid	202,795.80
21. 21.89	154.1226	C9H19NO	Nonanamide	Amide	349,356.50
22. 24.39	218.7771	C28H58	Octacosane	Alkane	171,462.67
23. 29.30	408.3768	C32H52O2	Olean-12-en-3-ol, acetate, (3β)-	Triterpenoid	210,758.00
24. 17.09	224.0999	C22H23NO4	Phthalic acid, 4-cyanophenyl heptyl ester	Ester	454,868.00
25. 23.33	218.8161	C20H30O4	Phthalic acid, heptyl 3-methylbutyl ester	Ester	4577,088.00
26. 16.70	218.8513	C20H40O	Phytol	Diterpenoid	202,160.25
27. 14.32	218.8335	C15H24O	Tetracyclo[6.3.2.0(2,5).0(1,8)]tridecan-9-ol, 4,4-dimethyl-	No records	91,373.50
28. 17.65	227.2006	C14H28O2	Tridecanoic acid, methyl ester	Methyl ester	380,039.50
29. 30.36	283.8030	C18H45AsO3Si3	Tris(tert-butyldimethylsilyloxy)arsane	Ester	29,655.00
30. 19.68	199.1691	C12H24O2	Undecanoic acid, methyl ester	Methyl ester	74,944.00
31. 14.46	200.1558	C15H20	α-Calacorene	Sesquiterpenoid	49,402.00
32. 27.58	431.3842	C31H52O3	α-Tocopheryl acetate	Triterpenoid	183,414.80
33. 28.36	401.3731	C31H52O2	β-Sitosterol acetate	Triterpenoid	696,117.67

,

Table 8. Compounds identified in leaf ethanol extracts of Ekebergia capensis.

RT (min)	Observed Ion m/z	MF.	Name	MC	FC
1. 13.49	218.9559	C15H24O	(-)-Spathulenol	Sesquiterpenoid	225,729.33
2. 23.93	150.1032	C12H15ClN2	(1R,2R,4S)-2-(6-Chloropyridin-3-yl)-7-methyl-7-azabicyclo[2.2.1]heptane	Epibatidine analogues	148,243.33
3. 13.98	220.1821	C15H24O	(1R,3E,7E,11R)-1,5,5,8-Tetramethyl-12-oxabicyclo[9.1.0]dodeca-3,7-diene	Epoxide	499,685.75
4. 29.29	263.9630	C13H20N2SSi	1,2-Benzisothiazol-3-amine, TBDMS derivative	Sugar	23,401.00
5. 14.34	218.7645	C15H24O	10,10-Dimethyl-2,6-dimethylenebicyclo[7.2.0]undecan-5β-ol		193,820.25
6. 19.99	265.2496	C21H36O2	11,14,17-Eicosatrienoic acid, methyl ester	Methyl ester	815,008.50
7. 12.74	180.1142	C11H16O2	2(4H)-Benzofuranone, 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-	Benzofuran	260,204.00
8. 4.15	110.0360	C6H6O2	2-Furancarboxaldehyde, 5-methyl-	Aryl-aldehyde	76,995.50
9. 4.59	112.0154	C5H4O3	2H-Pyran-2,6(3H)-dione	Valerolactone	166,899.00
10. 8.89	150.0679	C9H10O2	2-Methoxy-4-vinylphenol	Ketone	215,229.67
11. 5.13	102.0550	C6H13NO	2-Pyrrolidinemethanol, 1-methyl-	Proline	1586,572.00
12. 16.80	193.1957	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	441,117.67
13. 17.00	278.2967	C20H40O	3,7,11,15-Tetramethyl-2-hexadecen-1-ol	Diterpenoid	321,637.00
14. 14.96	218.7685	C20H27FO2	3-Fluorobenzoic acid, tridec-2-ynyl ester	Organofluorine compound	255,232.00
15. 6.58	144.0415	C6H8O4	4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-	Fatty acid	1257,832.00
16. 13.21	200.1558	C15H20	4-Isopropyl-6-methyl-1-methylene-1,2,3,4-tetrahydronaphthalene	Sesquiterpenoid	67,046.83
17. 28.47	340.8050	C24H36O2Si2	4-Methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene, 2TMS derivative	Bisphenol A	17,941.50
18. 15.56	218.8078	C13H20O2	6,6-Dimethyl-2-(3-oxobutyl)bicyclo[3.1.1]heptan-3-one	Oxepane	360,494.00
19. 16.14	196.1090	C11H16O3	6-Hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one	Benzofuran	480,778.00
20. 15.70	180.0778	C15H26O2	7-Acetyl-2-hydroxy-2-methyl-5-isopropylbicyclo[4.3.0]nonane	Sesquiterpenoid	296,149.33
21. 21.89	282.2742	C18H35NO	9-Octadecenamide, (Z)-	Fatty amide	875,563.20
22. 10.36	122.0361	C7H6O2	Benzaldehyde, 4-hydroxy-	Hydroxybenzaldehyde	78,283.50
23. 28.39	400.3717	C28H48O	Campesterol	Ergosterol	683,575.33
24. 14.80	218.9483	C15H24O	Caryophylla-4(12),8(13)-dien-5α-ol	Sesquiterpenoid	309,195.00
25. 13.60	220.1821	C15H24O	Caryophyllene oxide	Sesquiterpenoid	768,061.33
26. 8.55	110.0361	C6H6O2	Catechol	Catechol	198,727.00
27. 27.36	379.3372	C27H44O	Cholesta-4,6-dien-3-ol, (3β)-	Cholesterol	293,677.67
28. 13.34	218.7878	C12H7Cl5O4	Fumaric acid, ethyl pentachlorophenyl ester	Ester	166,528.00
29. 3.38	97.0278	C4H8O4	Glycolaldehyde dimer	Pentose	8,931.50
30. 20.31	226.2170	C16H33NO	Hexadecanamide	Fatty amide	594,910.67
31. 23.05	258.2501	C19H38O4	Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester	1-monoacylglycerol	184,585.67
32. 2.60	32.0564	H4N2	Hydrazine	Non-metal compound	24,186.67
33. 2.97	32.0261	CH4O	Methyl Alcohol	Alcohol	1931,798.17
34. 14.84	198.1405	C15H18	Naphthalene, 1,6-dimethyl-4-(1-methylethyl)-	Sesquiterpenoid	72,764.67
35. 16.72	278.2967	C20H38	Neophytadiene	Diterpenoid	454,427.18
36. 18.26	256.0055	C16H32O2	n-Hexadecanoic acid	Fatty acid	2543,102.33
37. 6.28	85.0840	C6H13NO	N-Methyl-L-prolinol	Amino acid	957,665.00
38. 20.13	284.2714	C18H36O2	Octadecanoic acid	Fatty acid	650,507.00
39. 12.24	206.1660	C14H22O	Phenol, 3,5-bis(1,1-dimethylethyl)-	Sesquiterpenoid	100,587.50
40. 18.16	279.1556	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	7104,005.33
41. 19.61	278.2963	C20H40O	Phytol	Diterpenoid	714,988.60
42. 28.60	412.3707	C29H48O	Stigmasterol	Steroid	825,673.33
43. 15.83	228.2081	C14H28O2	Tetradecanoic acid	Fatty acid	274,646.67
44. 18.28	213.1522	C13H26O2	Tridecanoic acid	Fatty acid	5679,271.50
45. 17.67	228.2043	C14H28O2	Tridecanoic acid, methyl ester	Methyl ester	307,666.00
46. 17.69	143.0654	C12H24O2	Undecanoic acid, methyl ester	Methyl ester	255,331.00
47. 12.89	200.1555	C15H20	α-Calacorene	Sesquiterpenoid	60,816.33
48. 27.60	431.3854	C31H52O3	α-Tocopheryl acetate	Triterpenoid	681,154.00
49. 29.34	426.3876	C30H50O	β-Amyrin	Triterpenoid	390,576.00
50. 29.01	414.3870	C29H50O	β-Sitosterol	Triterpenoid	1529,284.00

,

Table 9. Compounds identified in leaf acetone extracts of Melia azedarach.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 30.53	248.8762	C11H10O6	1,2,4-Benzenetricarboxylic acid, 1,2-dimethyl ester	Benzoic acid	21,666.00
2. 30.13	265.2098	C13H20N2SSi	1,2-Benzisothiazol-3-amine, TBDMS derivative	Sugar	23,300.33
3. 28.24	208.9309	C12H22Si2	1,2-Bis(trimethylsilyl)benzene	Organosilicon	11,527.50
4. 16.78	218.8432	C14H28O	2-Tetradecanone	Ketone	182,214.50
5. 21.78	218.8388	C21H40O2	4,8,12,16-Tetramethylheptadecan-4-olide	Beta-diketone	73,950.50
6. 30.24	258.8419	C24H36O2Si2	4-Methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene, 2TMS derivative	Bisphenol A	56,309.00
7. 14.92	218.9359	C14H20O3	8-(2-Acetyloxiran-2-yl)-6,6-dimethylocta-3,4-dien-2-one	Fatty alcohol ester	151,894.00
8. 23.33	168.0373	C24H38O4	Bis(2-ethylhexyl) phthalate	Ester	54,139.00
9. 28.57	394.3614	C29H46	Cholesta-6,22,24-triene, 4,4-dimethyl-	Cholesterol	449,205.00
10. 28.25	207.9947	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	22,319.83
11. 20.34	218.9400	C27H56	Heptacosane	Alkane	136,232.20
12. 18.43	218.9511	C16H34	Hexadecane	Alkane	461,468.60
13. 2.59	32.0036	H4N2	Hydrazine	Non-metal compound	31,792.00
14. 2.93	33.0194	H3NO	Hydroxylamine	Amine	687,694.00
15. 24.40	206.8313	C20H42O	Isobutyl hexadecyl ether	Ether	99,861.00
16. 15.46	218.8891	C19H18F2O4	Isophthalic acid, 3,5-difluorophenyl pentyl ester	Ester	9,181.00
17. 2.97	32.0260	CH4O	Methyl Alcohol	Alcohol	2893,853.89
18. 16.70	218.8535	C20H38	Neophytadiene	Diterpenoid	212,138.00
19. 20.24	130.9100	C9H19NO	Nonanamide	Amide	100,542.80
20. 19.59	278.2969	C20H40O	Phytol	Diterpenoid	354,182.00
21. 17.66	227.2007	C14H28O2	Tridecanoic acid, methyl ester	Methyl ester	263,243.33
22. 30.06	340.7472	C18H45AsO3Si3	Tris(tert-butyldimethylsilyloxy)arsane	Ester	21,078.67
23. 19.68	218.8605	C12H24O2	Undecanoic acid, methyl ester	Methyl ester	67,474.00
24. 29.63	432.3895	C31H52O3	α-Tocopheryl acetate	Triterpenoid	222,825.33
25. 28.37	401.3752	C31H52O2	β-Sitosterol acetate	Triterpenoid	548,590.25

,

Table 10. Compounds identified in leaf ethanol extracts of Melia azedarach.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 14.94	218.9352	C13H16O4	1,6,6-Trimethyl-7-(3-oxobut-1-enyl)-3,8-dioxatricyclo[5.1.0.0(2,4)]octan-5-one	Ketone	208,378.00
2. 17.00	138.1403	C16H30	1-Hexadecyne	Hydrocarbon	146,746.50
3. 17.00	278.2964	C18H34	1-Octadecyne	Hydrocarbon	182,460.00
4. 2.77	43.0049	C2H5ClO	2-Chloroethanol	Chloroethanol	10,825.00
5. 12.38	155.0941	C8H13NO2	2-Hydroxy-1-(1′-pyrrolidiyl)-1-buten-3-one	No record	163,420.00
6. 16.79	218.8744	C14H28O	2-Tetradecanone	Ketone	191,685.50
7. 16.79	218.8549	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	177,821.00
8. 16.94	40.9534	C2H4N2	3-Methyl-1,2-diazirine	No record	10,163.33
9. 16.30	144.0416	C6H8O4	4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-	Fatty acid	419,184.67
10. 21.87	218.9503	C18H35NO	9-Octadecenamide, (Z)-	Fatty amide	368,824.25
11. 12.30	220.1819	C15H24O	Butylated Hydroxytoluene	Phenylpropane	26,415.67
12. 28.39	405.0388	C31H52O3	Cholesterol 3-O-[[2-acetoxy]ethyl]-	No record	498,714.50
13. 29.66	430.3826	C29H50O2	dl-α-F	Resorcinol	505,469.00
14. 20.27	130.9692	C12H25NO	Dodecanamide	Fatty amide	74,969.00
15. 13.24	128.0426	C12H7Cl5O4	Fumaric acid, ethyl pentachlorophenyl ester	Ester	90,985.50
16. 20.27	130.9721	C16H33NO	Hexadecanamide	Fatty amide	107,671.50
17. 2.90	32.0228	CH4O	Methyl Alcohol	Alcohol	1607,627.00
18. 13.03	157.1220	C10H20O2	n-Decanoic acid	Fatty acid	86,722.40
19. 18.19	124.0390	C20H38	Neophytadiene	Diterpenoid	454,350.71
20. 17.21	256.2401	C16H32O2	n-Hexadecanoic acid	Fatty acid	1632,949.33
21. 17.21	154.1226	C9H19NO	Nonanamide	Amide	223,305.67
22. 22.39	340.2390	C23H32O2	Phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl-	Diterpenoid	40,545.33
23. 12.23	206.1636	C14H22O	Phenol, 2,5-bis(1,1-dimethylethyl)-	Sesquiterpenoid	29,976.67
24. 18.16	278.1512	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	4299,525.00
25. 17.11	223.0966	C21H25NO3	Phthalic acid, monoamide, N-ethyl-N-(3-methylphenyl)-, isobutyl ester	Ester	197,285.67
26. 19.62	278.2964	C20H40O	Phytol	Diterpenoid	658,427.67
27. 29.10	331.0378	C29H48O	Stigmasta-5,24(28)-dien-3-ol, (3β,24Z)-	Steroid	57,701.00
28. 28.61	412.3719	C29H48O	Stigmasterol	Steroid	701,624.67
29. 21.80	130.8943	C10H16O2	Tetrahydrofuran-2-one, 3-[2-pentenyl]-4-methyl-	Fatty acid ester	65,973.00
30. 19.56	85.0282	C17H30O3	Tetrahydropyran Z-10-dodecenoate	Ester	18,107.50
31. 17.68	218.9267	C14H28O2	Tridecanoic acid, methyl ester	Methyl ester	119,263.00
32. 27.60	431.3843	C31H52O3	α-Tocopheryl acetate	Triterpenoid	70,903.00
33. 29.01	414.3875	C29H50O	β-Sitosterol	Triterpenoid	1380,935.00

,

Table 11. Compounds identified in leaf acetone extracts of Trichilia dregeana.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 20.94	272.2504	C20H32	(R,1E,5E,9E)-1,5,9-Trimethyl-12-(prop-1-en-2-yl)cyclotetradeca-1,5,9-triene	Diterpenoid	661,369.50
2. 29.36	263.7976	C13H20N2SSi	1,2-Benzisothiazol-3-amine, TBDMS derivative	Sugar	24,657.75
3. 5.25	109.1014	C8H14	1,6-Heptadiene, 2-methyl-	Alkadiene	241,431.50
4. 18.65	277.2445	C20H34O	1H-Naphtho[2,1-b]pyran, 3-ethenyldodecahydro-3,4a,7,7,10a-pentamethyl-, [3R-(3α,4aβ,6aα,10aβ,10bα)]-	Triterpenoid	254,957.50
5. 21.38	218.9118	C15H26O	1-Naphthalenemethanol, 1,4,4a,5,6,7,8,8a-octahydro-2,5,5,8a-tetramethyl-	Sesquiterpenoid	910,101.00
6. 22.82	292.1670	C17H24O4	2-Hydroxy-4-methoxy-7-methyl-7,8,9,10,11,12,13,14-octahydro-6-oxabenzocyclododecen-5-one	Gingerdione	53,596.00
7. 16.78	180.1858	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	498,290.33
8. 21.78	263.8585	C21H40O2	4,8,12,16-Tetramethylheptadecan-4-olide	Beta-diketone	288,631.33
9. 29.60	281.9882	C17H30OSi	4-tert-Octylphenol, TMS derivative	Alkylbenzene	32,218.33
10. 21.69	270.2347	C20H30	Bicyclo[3.1.1]hept-2-ene, 2,2′-(1,2-ethanediyl)bis[6,6-dimethyl-	Diterpenoid	205,660.50
11. 23.33	218.8484	C24H38O4	Bis(2-ethylhexyl) phthalate	Ester	105,403.33
12. 21.69	289.2480	C26H40O2	Butyl 4,7,10,13,16,19-docosahexaenoate	Fatty acid	286,373.50
13. 20.88	263.9540	C20H40O2	Butyric acid, hexadecyl ester	Fatty acid	180,132.50
14. 28.14	226.1588	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	21,468.33
15. 18.15	278.1513	C16H22O4	Dibutyl phthalate	Ester	5113,869.00
16. 15.29	87.0440	C13H26O2	Dodecanoic acid, 2-methyl-	Ester	161,611.50
17. 18.47	263.8584	C20H42	Eicosane	Alkane	491,217.33
18. 28.36	417.0340	C30H50O2	Ergost-5-en-3-ol, acetate, (3β,24R)-	Triterpenoid	303,607.00
19. 20.35	218.8367	C27H56	Heptacosane	Alkane	179,363.50
20. 13.54	130.8832	C16H34	Hexadecane	Alkane	578,509.80
21. 20.96	263.8346	C21H44O	Hexadecyl pentyl ether	Ether	415,977.00
22. 2.58	32.0175	H4N2	Hydrazine	Non-metal compound	195,016.33
23. 21.06	272.2508	C20H32	Kaur-15-ene	Diterpenoid	464,961.67
24. 2.89	32.0474	CH4O	Methyl Alcohol	Alcohol	3486,357.33
25. 16.70	218.8848	C20H38	Neophytadiene	Diterpenoid	115,963.50
26. 20.27	130.9004	C9H19NO	Nonanamide	Amide	132,986.33
27. 18.37	272.2506	C20H32	Phenanthrene, 7-ethenyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydro-1,1,4a,7-tetramethyl-, [4aS-(4aα,4bβ,7β,10aβ)]-	Diterpenoid	728,659.00
28. 17.09	223.0964	C22H23NO4	Phthalic acid, 4-cyanophenyl heptyl ester	Ester	230,352.00
29. 19.58	278.2973	C20H40O	Phytol	Diterpenoid	287,838.33
30. 28.57	412.3716	C29H48O	Stigmasterol	Steroid	308,190.00
31. 3.08	70.0412	C2H4OS	Thioacetic acid	Alkylthiol	687,016.50
32. 17.67	227.2003	C14H28O2	Tridecanoic acid, methyl ester	Fatty acid ester	219,513.33
33. 18.43	130.9689	C4BrF9	Tris(trifluoromethyl) bromomethane		19,641.50
34. 27.58	430.3812	C29H50O2	Vitamin E	Resorcinol	173,224.00
35. 21.06	218.8441	C15H24O	α-Santalol	7-hydroxycoumarin	82,416.00
36. 27.58	432.3888	C31H52O3	α-Tocopheryl acetate	Triterpenoid	186,539.25
37. 28.99	414.3867	C29H50O	β-Sitosterol	Triterpenoid	1328,446.00
38. 29.98	412.3719	C29H48O	γ-Sitostenone	Steroid	519,588.00

,

Table 12. Compounds identified in leaf ethanol extracts of Trichilia dregeana.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 13.97	218.9516	C15H24O	(1R,3E,7E,11R)-1,5,5,8-Tetramethyl-12-oxabicyclo[9.1.0]dodeca-3,7-diene	Epoxide	100,323.50
2. 20.96	275.2370	C20H34O	(E)-3-Methyl-5-((1R,4aR,8aR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)pent-2-en-1-ol	Diterpenoid	545,931.00
3. 22.71	118.9170	C12H10Cl2O4	1,2-Benzenediol, o-dichloroacetyl-o′-cyclopropanecarbonyl-		9,766.00
4. 30.62	266.9226	C13H20N2SSi	1,2-Benzisothiazol-3-amine, TBDMS derivative	Sugar	30,994.67
5. 26.17	280.9730	C20H34O	1,6,10,14-Hexadecatetraen-3-ol, 3,7,11,15-tetramethyl-, (E,E)-	Diterpenoid	320,433.80
6. 5.25	96.0564	C8H14	1,6-Heptadiene, 2-methyl-	Alkadiene	241,432.00
7. 18.67	276.2407	C20H34O	1H-Naphtho[2,1-b]pyran, 3-ethenyldodecahydro-3,4a,7,7,10a-pentamethyl-, [3R-(3α,4aβ,6aα,10aβ,10bα)]-	Triterpenoid	370,766.67
8. 23.14	218.8896	C15H26O	2,6,10-Dodecatrien-1-ol, 3,7,11-trimethyl-	Sesquiterpenoid	136,124.67
9. 12.49	218.9198	C15H24O	2,6,10-Dodecatrienal, 3,7,11-trimethyl-, (E,E)-	Sesquiterpenoid	141,636.50
10. 22.84	292.1672	C17H24O4	2-Hydroxy-4-methoxy-7-methyl-7,8,9,10,11,12,13,14-octahydro-6-oxabenzocyclododecen-5-one	Gingerdione	45,244.00
11. 16.80	179.1786	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	393,929.33
12. 20.91	263.8061	C14H28O3	3-Hydroxymyristic acid	Fatty acid	161,204.00
13. 21.21	274.2300	C19H30O	4,14-Dimethyl-11-isopropyltricyclo[7.5.0.0(10,14)]tetradec-4-en-8-one	Androgen	101,356.00
14. 21.80	263.9405	C21H40O2	4,8,12,16-Tetramethylheptadecan-4-olide	Beta-diketone	269,254.50
15. 11.17	130.8733	C7H12O	4-Hepten-2-one, (E)-	Organooxygen compound	136,106.00
16. 21.88	263.8605	C18H35NO	9-Octadecenamide, (Z)-	Fatty amide	708,408.50
17. 21.71	289.2489	C26H40O2	Butyl 4,7,10,13,16,19-docosahexaenoate	Fatty acid	318,610.00
18. 12.29	220.1824	C15H24O	Butylated Hydroxytoluene	Phenylpropane	27,910.67
19. 2.88	41.0132	CH6N4O	Carbohydrazide	Carbohydrazide	151,106.00
20. 23.54	257.2272	C12H25NO	Dodecanamide	Fatty amide	55,399.50
21. 17.69	227.2003	C13H26O2	Dodecanoic acid, methyl ester	Methyl ester	127,277.00
22. 2.62	31.0644	C2H4Cl2O	Ethanol, 2,2-dichloro-	Alcohol	12,654.00
23. 21.41	218.8306	C15H26O	Humulane-1,6-dien-3-ol	Sesquiterpenoid	1117,231.00
24. 11.43	130.9770	C15H24	Humulene	Sesquiterpenoid	33,834.00
25. 2.86	32.0543	H4N2	Hydrazine	Non-metal compound	29,779.50
26. 21.08	272.2510	C20H32	Kaur-15-ene	Diterpenoid	494,925.33
27. 2.65	31.9949	CH4O	Methyl Alcohol	Alcohol	1822,640.42
28. 15.82	171.1382	C10H20O2	n-Decanoic acid	Fatty acid	115,234.67
29. 16.72	137.1327	C20H38	Neophytadiene	Diterpenoid	139,113.50
30. 18.22	256.2398	C16H32O2	n-Hexadecanoic acid	Fatty acid	1293,680.33
31. 18.39	272.2504	C20H32	Phenanthrene, 7-ethenyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydro-1,1,4a,7-tetramethyl-, [4aS-(4aα,4bβ,7β,10aβ)]-	Diterpenoid	807,281.67
32. 22.39	340.2411	C23H32O2	Phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl-	Diterpenoid	67,053.50
33. 12.22	206.1663	C14H22O	Phenol, 2,5-bis(1,1-dimethylethyl)-	Sesquiterpenoid	41,210.00
34. 15.89	218.9111	C3F9P	Phosphine, tris(trifluoromethyl)-	Organofluorine	14,308.25
35. 18.17	278.1507	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	3770,875.00
36. 17.11	223.0962	C21H25NO3	Phthalic acid, monoamide, N-ethyl-N-(3-methylphenyl)-, isobutyl ester	Ester	244,482.50
37. 19.61	137.1326	C20H40O	Phytol	Diterpenoid	223,292.75
38. 28.34	380.3446	C29H48O	Stigmasta-5,24(28)-dien-3-ol, (3β,24Z)-	Steroid	234,342.50
39. 25.42	218.9552	C30H50	Supraene	Triterpenoid	565,315.33
40. 27.60	431.3852	C31H52O3	α-Tocopheryl acetate	Triterpenoid	264,498.80
41. 29.01	414.3875	C29H50O	β-Sitosterol	Triterpenoid	1371,309.00
42. 30.00	412.3724	C29H48O	γ-Sitostenone	Steroid	540,348.67
43. 27.05	416.3666	C28H48O2	γ-Tocopherol	Steroid	121,387.50

,

Table 13. Compounds identified in leaf acetone extracts of Turraea floribunda.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 15.00	220.1822	C15H24O	((4aS,8S,8aR)-8-Isopropyl-5-methyl-3,4,4a,7,8,8a-hexahydronaphthalen-2-yl)methanol	Sesquiterpenoid	171,920.00
2. 19.57	201.1638	C15H24	(1R,4S,5S)-1,8-Dimethyl-4-(prop-1-en-2-yl)spiro[4.5]dec-7-ene	Hydrocarbon	192,589.50
3. 26.14	263.8413	C20H32	(E,E,E)-3,7,11,15-Tetramethylhexadeca-1,3,6,10,14-pentaene	Diterpenoid	480,221.00
4. 21.84	273.2215	C20H32	1,3,6,10-Cyclotetradecatetraene, 3,7,11-trimethyl-14-(1-methylethyl)-, [S-(E,Z,E,E)]-	Diterpenoid	484,433.00
5. 20.78	201.1639	C15H22	1,3,7,11-Cyclotetradecatetraene, 2-methyl-		902,135.00
6. 18.80	263.7967	C20H34O	1,6,10,14-Hexadecatetraen-3-ol, 3,7,11,15-tetramethyl-, (E,E)-	Diterpenoid	650,540.67
7. 13.56	202.1714	C15H26	1H-3a,7-Methanoazulene, octahydro-1,4,9,9-tetramethyl-	Sesquiterpenoid	128,891.33
8. 8.68	142.0775	C11H10	1H-Indene, 1-ethylidene-	Hydrocarbon	28,659.00
9. 12.71	161.1324	C11H16O2	2(4H)-Benzofuranone, 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-, (R)-	Benzofuran	135,928.67
10. 26.14	280.9475	C22H36O2	2,6,10,14-Hexadecatetraen-1-ol, 3,7,11,15-tetramethyl-, acetate, (E,E,E)-	Fatty alcohol	176,010.50
11. 15.19	210.1614	C13H22O2	2-Cyclohexen-1-one, 4-(3-hydroxybutyl)-3,5,5-trimethyl-	Apocarotenoid	82,345.33
12. 16.79	263.8863	C18H36O	2-Pentadecanone, 6,10,14-trimethyl-	Ketone	1520,735.33
13. 16.97	263.7692	C20H40O	3,7,11,15-Tetramethyl-2-hexadecen-1-ol	Diterpenoid	19,984.50
14. 25.67	218.8406	C15H23N	3-Cyano-3-octyl-1,4-cyclohexadiene		98,440.00
15. 5.24	105.0696	C8H14	4-Methyl-1,5-Heptadiene	Alkene	238,594.00
16. 12.47	221.1901	C15H24O	6,10-Dodecadien-1-yn-3-ol, 3,7,11-trimethyl-	Fatty alcohol	132,884.67
17. 20.45	263.8287	C21H36O4	9,12,15-Octadecatrienoic acid, 2,3-dihydroxypropyl ester, (Z,Z,Z)-	Lineolic acid	24,402.00
18. 21.75	288.2451	C32H54O2	9,19-Cyclolanostan-3-ol, acetate, (3β)-	Cycloartanol	185,601.00
19. 3.21	43.0106	C2H6N2O	Acetic acid, hydrazide	N-nitroso compound	9,648.50
20. 3.40	130.9333	C2H4O3	Acetic acid, hydroxy-	Hydroxy acid	16,192.00
21. 8.01	136.0518	C8H8O2	Benzeneacetic acid	Benzene	823,393.50
22. 20.33	218.8824	C11H16FNO3	Benzeneethanamine, 2-fluoro-β,3,4-trihydroxy-N-isopropyl-	Organofluorine compound	461,586.67
23. 21.65	274.2253	C20H34O2	Butyl 6,9,12-hexadecatrienoate	No records	120,874.00
24. 20.40	263.7774	C20H30O2	cis-5,8,11,14,17-Eicosapentaenoic acid	Fatty acid	67,970.33
25. 14.77	218.7973	C15H24O	cis-Z-α-Bisabolene epoxide	Sesquiterpenoid	163,987.00
26. 29.61	224.8923	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	37,777.00
27. 6.10	130.9737	C10H11N3O2	dl-7-Azatryptophan	L-alpha-amino acid	5,636.50
28. 27.58	430.3826	C29H50O2	dl-α-Tocopherol	Resorcinol	308,112.50
29. 18.43	218.9230	C20H42	Eicosane	Alkane	773,942.50
30. 28.37	401.3748	C30H50O2	Ergost-5-en-3-ol, acetate, (3β,24R)-	Triterpenoid	400,755.50
31. 16.60	134.1088	C12H18	Geijerene	Monoterpenoid	506,492.50
32. 4.79	68.9660	C3H8O3	Glycerin	Sugar alcohol	1247,390.50
33. 20.35	263.9279	C27H56	Heptacosane	Alkane	459,191.00
34. 13.54	154.1719	C16H34	Hexadecane	Alkane	887,579.50
35. 2.58	32.0644	H4N2	Hydrazine	Non-metal compound	16,395.00
36. 21.65	218.9095	C15H24O	Isoaromadendrene epoxide	Sesquiterpenoid	87,763.50
37. 17.91	278.2969	C20H40O	Isophytol	Diterpenoid	581,608.33
38. 21.36	263.8432	C22H34O2	Methyl 6,9,12,15,18-heneicosapentaenoate	Methyl ester	222,155.00
39. 19.47	263.8150	C18H30O2	Methyl 8,11,14-heptadecatrienoate	Methyl ester	143,481.00
40. 2.63	32.0319	CH4O	Methyl Alcohol	Alcohol	2542,812.29
41. 16.70	218.9458	C20H38	Neophytadiene	Diterpenoid	455,672.53
42. 17.92	218.9160	C18H36O	Octadecanal	Fatty aldehyde	7,428.50
43. 22.38	340.2405	C23H32O2	Phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl-	Diterpenoid	98,778.00
44. 12.20	206.1665	C14H22O	Phenol, 2,6-bis(1,1-dimethylethyl)-	Sesquiterpenoid	26,409.00
45. 17.09	263.7937	C22H23NO4	Phthalic acid, 4-cyanophenyl heptyl ester	Ester	863,842.00
46. 23.33	279.1599	C33H56O4	Phthalic acid, heptadecyl 2-propylpentyl ester	Ester	192,600.50
47. 18.14	279.1561	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	7570,367.00
48. 2.96	31.4619	H4Si	Silane	Non-metal compound	14,625.00
49. 29.96	412.3726	C29H48O	Stigmast-4-en-3-one	Steroid	315,755.67
50. 25.39	231.2112	C30H50	Supraene	Triterpenoid	784,372.00
51. 15.80	218.9575	C14H28O2	Tetradecanoic acid	Fatty acid	201,837.50
52. 7.28	86.0223	C4H6S	Thiophene, 2,3-dihydro-	Dihydrothiophene	156,903.67
53. 13.54	218.8948	C13H28	Tridecane	Alkane	208,627.00
54. 17.65	228.2039	C14H28O2	Tridecanoic acid, methyl ester	Methyl ester	395,572.00
55. 12.99	157.1222	C11H22O2	Undecanoic acid	Methyl ester	51,909.00
56. 12.87	157.1011	C15H20	α-Calacorene	Sesquiterpenoid	30,917.33
57. 29.63	431.3858	C31H52O3	α-Tocopheryl acetate	Triterpenoid	199,285.00
58. 21.51	218.7617	C15H24O	β-Santalol	Sesquiterpenoid	80,032.50
59. 28.98	414.3873	C29H50O	β-Sitosterol	Triterpenoid	833,435.33

and

Table 14. Compounds identified in leaf ethanol extracts of Turraea floribunda.

RT (min)	Observed Ion m/z	MF.	Name	MC	FC
1. 28.27	218.8544	C13H20N2SSi	1,2-Benzisothiazol-3-amine, TBDMS derivative	Sugar	21,941.25
2. 16.77	130.9077	C16H30O2	2,15-Hexadecanedione	Fatty acid	8,739.00
3. 2.79	42.9883	C2H5ClO	2-Chloroethanol	Chloroethanol	17,013.50
4. 17.66	218.9181	C9H16BrNO	2-Piperidinone, N-[4-bromo-n-butyl]-	Delta-lactam	212,874.00
5. 16.78	218.8178	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	331,058.75
6. 30.93	250.8218	C28H46O2	4,4′-bi-4H-pyran, 2,2′,6,6′-tetrakis(1,1-dimethylethyl)-4,4′-dimethyl-		13,508.50
7. 27.65	206.9513	C24H36O2Si2	4-Methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene, 2TMS derivative	Bisphenol A	25,492.75
8. 28.52	207.8478	C17H30OSi	4-tert-Octylphenol, TMS derivative	Alkylbenzene	23,331.67
9. 6.56	144.0417	C6H8O4	4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-	Fatty acid	123,337.50
10. 28.19	263.7777	C9H27AsO3Si3	Arsenous acid, tris(trimethylsilyl) ester	Trialkylheterosilane	17,467.00
11. 21.85	218.9263	C11H16FNO3	Benzeneethanamine, 2-fluoro-β,3,4-trihydroxy-N-isopropyl-	Organofluorine compound	197,067.50
12. 28.20	208.8548	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	10,533.67
13. 18.93	130.8948	C10H11N3O2	dl-7-Azatryptophan	L-alpha-amino acid	13,803.00
14. 2.87	32.0230	H4N2	Hydrazine	Non-metal compound	29,112.33
15. 2.89	33.0078	H3NO	Hydroxylamine	Amine	19,835.67
16. 17.92	218.9493	C20H40O	Isophytol	Diterpenoid	126,936.00
17. 2.59	32.0438	CH4O	Methyl Alcohol	Alcohol	3945,937.00
18. 15.78	185.1534	C10H20O2	n-Decanoic acid	Fatty acid	56,292.00
19. 18.17	256.2398	C16H32O2	n-Hexadecanoic acid	Fatty acid	1236,320.33
20. 8.69	142.0773	C11H10	Naphthalene, 2-methyl-	Naphthalene	16,237.00
21. 16.71	137.1323	C20H38	Neophytadiene	Diterpenoid	212,701.60
22. 20.27	118.9582	C9H19NO	Nonanamide	Amide	135,588.33
23. 18.14	278.1516	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	4220,463.00
24. 19.59	278.2971	C20H40O	Phytol	Diterpenoid	332,925.75
25. 28.57	412.3722	C29H48O	Stigmasterol	Steroid	263,092.00
26. 19.68	218.8909	C14H28O2	Tridecanoic acid, methyl ester	Methyl ester	162,963.00
27. 28.28	218.8983	C18H45AsO3Si3	Tris(tert-butyldimethylsilyloxy)arsane	Ester	23,852.50
28. 17.66	199.1695	C12H24O2	Undecanoic acid, methyl ester	Methyl ester	230,369.50
29. 28.97	417.0367	C31H52O2	β-Sitosterol acetate	Triterpenoid	330,908.00

indicate active compounds present in each Meliaceae species using GC-MS analyses, with their retention time (RT), observed mass to charge ion ratio (m/z), molecular formula (MF), metabolite class (MC), and fold change (FC, the average of the peak area values obtained at the different injections of the same compound). In E. capensis acetone extracts, thirty-three compounds were identified (Table 7), most of which are triterpenoids (five), alkanes (three), esters (three), sesquiterpenoids (three), diterpenoids (two), methyl esters (two), and two compounds were unclassified. Ethanolic extracts of E. capensis in Table 8 identified fifty compounds, of which most are sesquiterpenoids (eight), fatty acids (five), diterpenoids (three), methyl esters (three), triterpenoids (three), benzofurans (two), esters (two), fatty amides (two), and one compound was unclassified.

Table 9 shows the results of acetone extracts of M. azedarach; twenty-six compounds were identified. Of these, two are classified as esters, alkanes (three), diterpenoids (two), methyl esters (two), non-metal compounds (two), organosilicons (two), and triterpenoid (two). Thirty-three compounds were identified in ethanolic extracts of M. azedarach, shown in Table 10. Four compounds are classified as esters, diterpenoids (three), fatty acids (three), fatty amides (three), hydrocarbons (two), ketones (two), steroids (two), triterpenoids (two), and three compounds were unclassified.

Thirty-nine compounds were identified in acetone extracts of T. dregeana (Table 11), most of which are diterpenoids (six), esters (four), triterpenoids (four), alkanes (three), fatty acids (two), non-metal compounds (two), steroids (two), and one compound was unclassified. Forty-three compounds were identified in ethanolic extracts of T. dregeana (Table 12), with most of the compounds in the classes: diterpenoids (seven), sesquiterpenoids (five), fatty acids (four), triterpenoids (four), steroids (three), alcohols (two), esters (two), fatty amides (two), and one compound was unclassified.

Acetone leaf extracts of T. floribunda (Table 13) had sixty compounds, of which seven are diterpenoids (seven), sesquiterpenoids (seven), alkanes (four), methyl esters (four), triterpenoids (four), non-metal compounds (three), esters (three), fatty acids (two), fatty alcohols (two), hydrocarbons (two), and three compounds were unclassified. Table 14 shows thirty compounds identified in ethanol extracts of T. floribunda; most of the chemical compounds belong to the chemical classes: fatty acids (four), diterpenoids (three), esters (two), methyl esters (two), non-metal compounds (two), and one compound was unclassified.

Table 15. Compounds identified in leaf acetone extracts of Turraea obtusifolia.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 15.00	220.1821	C15H24O	(1R,2R,4S,6S,7S,8S)-8-Isopropyl-1-methyl-3-methylenetricyclo[4.4.0.02,7]decan-4-ol	Sesquiterpenoid	126,668.00
2. 15.10	263.8326	C18H26O	1,3-Bis-(2-cyclopropyl,2-methylcyclopropyl)-but-2-en-1-one	2-benzopyran	92,518.50
3. 14.33	218.9465	C15H24O	10,10-Dimethyl-2,6-dimethylenebicyclo[7.2.0]undecan-5β-ol		219,693.33
4. 8.86	130.9685	C10H16O	2,4-Decadienal	Aldehyde	75,217.75
5. 16.78	179.1793	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	255,603.50
6. 11.98	202.1713	C15H22	3,5,11-Eudesmatriene	Sesquiterpenoid	56,152.67
7. 21.79	263.8648	C21H40O2	4,8,12,16-Tetramethylheptadecan-4-olide	Beta-diketone	410,582.00
8. 30.47	281.8219	C17H30OSi	4-tert-Octylphenol, TMS derivative	Alkylbenzene	27,817.50
9. 14.78	218.8204	C15H24O	6,10-Dodecadien-1-yn-3-ol, 3,7,11-trimethyl-	Fatty alcohol	206,334.00
10. 15.85	218.1667	C15H22O	7-Isopropenyl-1,4a-dimethyl-4,4a,5,6,7,8-hexahydro-3H-naphthalen-2-one		186,966.33
11. 20.00	263.9515	C20H34O2	8,11,14-Eicosatrienoic acid, (Z,Z,Z)-	Fatty acid	13,480.00
12. 19.94	280.2397	C18H32O2	9,12-Octadecadienoic acid (Z,Z)-	Fatty acid	44,571.00
13. 29.97	422.3937	C32H52O2	9,19-Cycloergost-24(28)-en-3-ol, 4,14-dimethyl-, acetate, (3β,4α,5α)-	Triterpenoid	119,424.50
14. 16.95	263.8819	C20H30O5	Andrographolide	Butyrolactone	182,421.67
15. 21.37	204.1875	C15H24	Azulene, 1,2,3,5,6,7,8,8a-octahydro-1,4-dimethyl-7-(1-methylethenyl)-, [1S-(1α,7α,8aβ)]-	Sesquiterpenoid	235,288.00
16. 8.67	142.0774	C11H10	Benzocycloheptatriene	Benzenoid	17,979.50
17. 27.85	218.8211	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	19,618.33
18. 10.01	130.9654	C10H11N3O2	dl-7-Azatryptophan	L-alpha-amino acid	12,483.25
19. 13.94	218.8738	C22H32O2	Doconexent	Fatty acid	40,765.00
20. 18.43	263.7630	C20H42	Eicosane	Alkane	644,244.67
21. 11.70	202.1715	C15H22	Eudesma-2,4,11-triene	Sesquiterpenoid	186,595.60
22. 20.31	263.9065	C16H33NO	Hexadecanamide	Fatty amide	235,968.00
23. 20.35	218.7788	C16H34	Hexadecane	Alkane	444,080.00
24. 2.59	32.0455	H4N2	Hydrazine	Non-metal compound	27,402.00
25. 17.91	263.7523	C20H40O	Isophytol	Diterpenoid	180,211.33
26. 14.93	220.1819	C15H24O	Ledene oxide-(II)	Sesquiterpenoid	165,643.67
27. 2.86	32.0231	CH4O	Methyl Alcohol	Alcohol	3308,314.78
28. 16.70	218.9564	C20H38	Neophytadiene	Diterpenoid	239,419.44
29. 18.21	256.2402	C16H32O2	n-Hexadecanoic acid	Fatty acid	1312,119.00
30. 16.22	218.7640	C15H32	Pentadecane	Alkane	703,400.00
31. 6.40	130.9444	C6H12O3	Pentanoic acid, 2-hydroxy-3-methyl-	Fatty acid	374,290.67
32. 17.09	263.7686	C21H23NO6	Phthalic acid, heptyl 4-nitrophenyl ester	Ester	403,612.00
33. 18.14	279.1556	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	4790,918.75
34. 19.59	279.2999	C20H40O	Phytol	Diterpenoid	423,228.75
35. 28.57	412.3719	C29H48O	Stigmasterol	Steroid	467,141.50
36. 15.79	185.1536	C14H28O2	Tetradecanoic acid	Fatty acid	105,645.50
37. 3.07	70.0287	C2H4OS	Thioacetic acid	Alkylthiol	27,616.00
38. 17.66	227.2008	C14H28O2	Tridecanoic acid, methyl ester	Fatty acid ester	449,472.00
39. 19.68	218.8289	C12H24O2	Undecanoic acid, methyl ester	Methyl ester	180,225.75
40. 27.58	430.3823	C29H50O2	Vitamin E	Resorcinol	262,653.50
41. 29.64	432.3904	C31H52O3	α-Tocopheryl acetate	Triterpenoid	295,293.67
42. 25.67	420.3571	C29H50O4	α-Tocospiro A	Steroid	141,624.33
43. 28.98	414.3868	C29H50O	β-Sitosterol	Triterpenoid	999,333.33

shows forty-four compounds identified in acetone extracts of T. obtusifolia; chemical classes with the most chemical compounds are: fatty acids (six), sesquiterpenoids (five), alkanes (three), diterpenoids (three), triterpenoids (three), esters (two), non-metal compounds (two), steroids (two), and two compounds were unclassified. There were forty-six compounds identified in ethanolic extracts of T. obtusifolia (

Table 16. Compounds identified in leaf ethanol extracts of Turraea obtusifolia.

RT (min)	Observed Ion m/z	MF	Name	MC	FC
1. 13.98	220.1814	C15H24O	(1R,3E,7E,11R)-1,5,5,8-Tetramethyl-12-oxabicyclo[9.1.0]dodeca-3,7-diene	Epoxide	360,103.67
2. 20.96	275.2379	C20H34O	(E)-3-Methyl-5-((1R,4aR,8aR)-5,5,8a-trimethyl-2-methylenedecahydronaphthalen-1-yl)pent-2-en-1-ol	Diterpenoid	115,266.00
3. 21.30	263.7396	C17H32O	(R)-(-)-14-Methyl-8-hexadecyn-1-ol	Fatty alcohol	73,991.50
4. 14.35	218.8756	C15H24O	10,10-Dimethyl-2,6-dimethylenebicyclo[7.2.0]undecan-5β-ol		385,059.67
5. 17.93	218.8876	C20H40O	1-Hexadecen-3-ol, 3,5,11,15-tetramethyl-	Diterpenoid	315,859.50
6. 12.74	177.0783	C11H16O2	2(4H)-Benzofuranone, 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-	Benzofuran	93,776.33
7. 12.38	155.0938	C8H13NO2	2-Hydroxy-1-(1′-pyrrolidiyl)-1-buten-3-one		99,138.00
8. 16.80	179.1793	C13H26O	2-Undecanone, 6,10-dimethyl-	Fatty aldehyde	295,979.67
9. 11.99	202.1717	C15H22	3,5,11-Eudesmatriene	Sesquiterpenoid	84,655.00
10. 16.73	178.9410	C20H40O	3,7,11,15-Tetramethyl-2-hexadecen-1-ol	Diterpenoid	23,305.00
11. 21.81	263.8249	C21H40O2	4,8,12,16-Tetramethylheptadecan-4-olide	Beta-diketone	348,560.00
12. 6.57	144.0418	C6H8O4	4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-	Fatty acid	842,545.00
13. 28.80	280.8152	C17H30OSi	4-tert-Octylphenol, TMS derivative	Alkylbenzene	31,758.67
14. 28.39	400.3725	C28H48O	5-Cholestene-3-ol, 24-methyl-	Steroid	548,943.50
15. 13.48	218.8472	C15H24O	6,10-Dodecadien-1-yn-3-ol, 3,7,11-trimethyl-	Fatty alcohol	153,763.25
16. 15.88	218.1668	C15H22O	7-Isopropenyl-1,4a-dimethyl-4,4a,5,6,7,8-hexahydro-3H-naphthalen-2-one		307,202.33
17. 20.97	272.2511	C18H30O2	9,12,15-Octadecatrienoic acid, (Z,Z,Z)-	Methyl ester	923,805.50
18. 19.49	218.9427	C19H32O2	9,12,15-Octadecatrienoic acid, methyl ester, (Z,Z,Z)-	Methyl ester	152,852.00
19. 19.88	263.7534	C18H32O2	9,12-Octadecadienoic acid (Z,Z)-	Fatty acid	14,775.50
20. 2.95	32.0576	C2H4O3	Acetic acid, hydroxy-	Hydroxy acid	8,158.50
21. 13.85	218.8142	C15H24O	Bergamotol, Z-α-trans-	Monoterpenoid	48,437.33
22. 13.60	218.8457	C15H24O	Caryophyllene oxide	Sesquiterpenoid	487,571.00
23. 14.61	218.8863	C15H24O	cis-Z-α-Bisabolene epoxide	Sesquiterpenoid	177,591.67
24. 31.24	218.9091	C6H18O3Si3	Cyclotrisiloxane, hexamethyl-	Organosilicon	22,405.75
25. 29.66	430.3832	C29H50O2	dl-α-Tocopherol	Resorcinol	429,663.00
26. 17.67	213.1853	C13H26O2	Dodecanoic acid, methyl ester	Methyl ester	353,733.33
27. 11.72	202.1716	C15H22	Eudesma-2,4,11-triene	Sesquiterpenoid	160,053.60
28. 13.27	130.9365	C12H9Cl3O4	Fumaric acid, ethyl 3,4,5-trichlorophenyl ester		53,322.00
29. 3.46	58.0088	C4H8O4	Glycolaldehyde dimer	Pentose	11,108.50
30. 14.96	220.1826	C15H24O	Ledene oxide-(II)	Sesquiterpenoid	335,514.67
31. 14.61	263.9254	C19H32O3	Methyl 2-hydroxy-octadeca-9,12,15-trienoate	Fatty acid	365,830.00
32. 2.97	32.0260	CH4O	Methyl Alcohol	Alcohol	3178,893.00
33. 16.72	221.1896	C20H38	Neophytadiene	Diterpenoid	260,778.86
34. 18.26	256.1901	C16H32O2	n-Hexadecanoic acid	Fatty acid	5461,473.67
35. 20.34	156.0941	C9H19NO	Nonanamide	Amide	370,402.80
36. 12.24	206.1660	C14H22O	Phenol, 2,6-bis(1,1-dimethylethyl)-	Sesquiterpenoid	60,234.00
37. 18.16	278.1520	C20H30O4	Phthalic acid, heptyl pentyl ester	Ester	7217,745.00
38. 19.61	278.2960	C20H40O	Phytol	Diterpenoid	507,674.67
39. 7.29	130.9626	C7H13NO2	Pyrrolidin-1-propionic acid	Proline	87,679.50
40. 7.28	133.1012	C6H12ClN	Pyrrolidine, 1-(2-chloroethyl)-	Haloalkyl	88,402.00
41. 28.60	412.3717	C29H48O	Stigmasterol	Steroid	585,313.00
42. 20.16	227.2011	C14H28O2	Tetradecanoic acid	Fatty acid	200,040.00
43. 14.81	219.9886	C15H24O	trans-Z-α-Bisabolene epoxide	Sesquiterpenoid	242,292.25
44. 27.60	430.3830	C29H50O2	Vitamin E	Resorcinol	309,983.50
45. 25.67	421.3605	C29H50O4	α-Tocospiro A	Steroid	220,431.00
46. 29.01	414.3884	C29H50O	β-Sitosterol	Triterpenoid	1141,657.00

), chemical classes with the most chemical compounds: sesquiterpenoids (seven), diterpenoids (five), fatty acids (five), methyl esters (three), steroids (three), fatty alcohols (two), resorcinols (two), and five compounds were unclassified.

3. Discussion

Most of the botanical extracts tested for their insecticidal activities proved to be effective repellents, feeding deterrents, and contact toxic against the S. frugiperda and P. xylostella larvae. Repellence, feeding deterrence, and contact toxicity of E. capensis, T. dregeana, Turraea floribunda, and T. obtusifolia extracts are recorded for the first time in this study. Melia azedarach was used as a positive control in this study as it is a well-known insecticidal plant in the Meliaceae family. The species has been proven to be an excellent insecticide against S. frugiperda [24,25,26,27,28,29,30,31]. In addition, M. azedarach extracts were found to be an effective botanical insecticide against P. xylostella in studies by Charleston et al. [32], Charleston et al. [12], Chen et al. [33], Chen et al. [34], Defagó et al. [35], Dilawari et al. [36], Dilawaxi et al. [37], Kumar et al. [38], Patil and Goud [39], Qiu et al. [40], Rani et al. [41], Sharma et al. [42], and Singh et al. [43].

Plant extracts with repellent activities are those with compounds that have irritating effects, causing insects to move away from them [44]. All plant extracts evaluated had repellence against the S. frugiperda and P. xylostella larvae, except for the ethanolic extracts of T. floribunda that had attractancy against the two tested larvae. However, there were interspecific differences as the botanical extracts were more susceptible as repellents to the P. xylostella larvae than to the S. frugiperda larvae (Table 1 and Table 2). Accordingly, seven extracts displayed repellency against P. xylostella larvae as follows: one in class V, three in IV, and five in III. In comparison, extracts displayed repellency against S. frugiperda according to the following level of activity: one in class V, two in IV, and one in III. It is not surprising that M. azedarach extracts were found to have the highest repellent activity against both S. frugiperda and P. xylostella larvae in this study, as this plant is known to have excellent repellent and insecticidal properties against several insect pests in several studies. Interestingly, T. dregeana recorded the same repellence activity as M. azedarach against both S. frugiperda and P. xylostella larvae. Against S. frugiperda, acetone extracts repelled 71% of the larvae (Table 1); meanwhile, against P. xylostella, acetone and ethanol extracts repelled 65% of the larvae (Table 2). Trichilia dregeana extracts in the study by Adinew [45] were found to have a highly positive protectant ability against Sitophilus zeamais Motschulsky (Maize weevil), which is also a major pest of maize similar to S. frugiperda. Extracts of T. floribunda moderately repelled the S. frugiperda larvae, while E. capensis and T. obtusifolia extracts recorded the lowest repellence activity.

Plants with antifeeding activities have compounds that, once consumed, cause the insects to stop feeding and eventually die due to starvation [44]. A study by Farag et al. [46] suggested that the plant extracts with feeding deterrence activity act as a stomach poison when ingested by insects. These feeding deterrent compounds could help reduce crop damage [18]. Melia azedarach aqueous extracts, followed by T. obtusifolia (aqueous and ethanol) and T. floribunda aqueous extracts, recorded the highest feeding deterrence activity against the S. frugiperda larvae. It does not come as a surprise that Turraea species recorded high feeding deterrence activity as in the study by Chimbe and Galley [47], another species of the genus, Turraea nilotica Kotschy & Peyr., was found to be effective against Sitophilus oryzae (rice weevil) larvae. Several studies also evaluated other species of the genus Trichilia for antifeedant properties. Trichilia elegans A.Juss. [48], T. pallens C.DC. [49], T. pallida Sw. [49], and T. roka (Forssk.) Chiov. [50] were found to have antifeedant activities against S. frugiperda larvae. Surprisingly, all T. dregeana extracts used in this study inhibited more P. xylostella larval feeding than M. azedarach extracts. This is contrary to the studies by Charleston et al. [32] and Dilawari et al. [36], where M. azedarach extracts recorded the highest antifeedant properties against the P. xylostella larvae. In this study, aqueous extracts of T. obtusifolia and ethanolic extracts of E. capensis also recorded high feeding deterrence activity against the P. xylostella larvae, with feeding deterrence coefficients of 86.74 and 85.79, respectively. The repellence activity of E. capensis coincides with that in the study by Champagne [51], in which the extracts acted as growth inhibitors and were toxic to Peridroma saucia Hübner (variegated cutworm) larvae. Trichilia silvatica C.DC. extracts were reported as good antifeedants against P. xylostella larvae [52].

Aqueous extracts of E. capensis and T. floribunda caused the highest S. frugiperda larval mortality, with recorded LC₅₀ values of 0.14 mg/kg and 0.56 mg/kg, respectively. In the current study, all extracts of M. azedarach were less toxic to the S. frugiperda larvae (with an LC₅₀ of 707.95 mg/kg). These results are contrary to the results obtained in the study by Bullangpoti et al. [26], where M. azedarach ethanolic extracts caused high mortality against the S. frugiperda with a recorded a lower LC₅₀ value of 1.4 g L⁻¹. Ekebergia capensis and T. dregeana extracts caused the least mortality to the larvae. However, in the study by Rioba and Stevenson [53], two members of the genus Trichilia, T. pallens C.DC., and T. pallida Sw., were found to cause high larval mortality against the S. frugiperda larvae. Trichilia trijuga Vell. extracts were found to be toxic to the Crocidolomia binotalis (cabbage cluster caterpillar) larvae [54] and T. americana (Sessé & Moc.) T.D.Penn. was toxic to the Trichoplusia ni (cabbage looper) and Pseudaletia unipuncta (armyworm moth) larvae [10]. On the other hand, all three extracts of M. azedarach and aqueous extracts of T. obtusifolia were more lethal to the P. xylostella larvae, with LC₅₀ values of 0.14 mg/kg and 1.78 mg/kg, respectively. Ekebergia capensis, T. dregeana, and T. floribunda extracts caused insignificant toxicity against the P. xylostella larvae. This is contrary to this present study, as higher levels (LC₅₀ value of 691.83 and 707.95 mg/kg) of the extracts of T. dregeana were needed to kill 50% of the larvae. Trichilia emetica methanol extracts resulted in high P. xylostella larval mortality with a recorded LC₅₀ value of 0.94 mg.m⁻¹ in the study by Munyemana and Alberto [55]. There may be a relationship between the toxicity against the P. xylostella of Turraea species screened in this study with the study of Essoung et al. [56] and Essoung et al. [57], where T. floribunda and other Turraea species T. abyssinica Hochst., T. nilotica Kotschy & Peyr., and T. wakefieldii Oliv. extracts were toxic to Tuta obsoluta (tomato leafminer) larvae. Growth inhibitory and toxicity activity of eight Trichilia species T. americana (Sesse & Mocino) Pennington, T. connaroides (Wright & Am.), T. glabra L., T. havanensis Jacq., T. hirta L., T. martiana C.DC, T. pleeana (A. Juss.) C.DC, and T. quadrijuga subsp. cinerascens (C.DC) Pennington extracts were evaluated on Peridroma saucia (variegated cutworm) and Spodoptera litura (cotton leafworm).

In the present work, ethanol extracts yielded the highest number of chemical compounds except for T. floribunda, where acetone extracts yielded 60 compounds, whereas ethanol yielded 30 compounds. This coincides with the antifeedant results, as ethanol extracts had better repellence, feeding deterrence, and contact toxicity than acetone extracts. Four chemical compounds were present in acetone and ethanol extracts of all five Meliaceae species studied: methyl alcohol, neophytadiene, phytol, and β-sitosterol. The tridecanoic acid methyl ester was present in all plant extracts except in ethanolic extracts of T. dregeana. The terpene derivatives phytol (present in all plant extracts in the current study) have been reported to have insecticidal [58] and pesticidal activities [59]. After all the chemical compounds identified in GC-MS analysis of plant extracts were classified, it was found that eight classes were common in all ethanol extracts. These were alcohols, diterpenoids, esters, fatty acids, fatty aldehydes, methyl esters, steroids, and triterpenoids. The five species’ most common classes in acetone extracts were alcohol, alkane, diterpenoid, ester, non-metal compound, organosilicon, and triterpenoid. All five plant species evaluated (either aqueous, acetone, or ethanol extracts) had repellence, feeding deterrence, and contact toxicity activity against S. frugiperda and P. xylostella larvae to some extent. The GC-MS analysis results strongly support these results as the two most well-known groups, phenols, and terpenes, known to have insecticidal and antifeedant properties, were present in all the plant extracts. Trichilia dregeana extracts exhibited excellent repellence activity and feeding deterrence against the two test larvae as the positive control, M. azedarach extracts. GC-MS analysis revealed that ethanol extracts of T. dregeana contained a high number of chemical classes that are terpenes (i.e., diterpenoid, sesquiterpenoid, triterpenoid, and steroid) and phenols (i.e., gingerdione). In acetone extracts of T. dregeana, four terpenes were identified (i.e., diterpenoid, sesquiterpenoid, triterpenoid, and steroid), as well as four phenols (i.e., 7-hydroxycoumarin, alkylbenzene, gingerdione, and resorcinol). Chemical compound phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl- identified in ethanolic extracts of T. dregeana was reported to have repellent, larvicidal, adulticidal, and oviposition deterrence activities against insects in a study by Chen et al. [60]. In studies by Curcino-Vieira et al. [61] and Tan and Luo [62], chemical compounds such as coumarins, diterpenes, flavonoids, glycosylated lignans, limonoids, monoterpenes, sesquiterpenes, steroids, and triterpenes isolated from the genus Trichilia were found to have insect feeding activities [63,64,65], and they may be toxic to insects [66,67]. Ekebergia capensis extracts exhibited good repellence, feeding deterrence, and contact toxicity against the test insects. GC-MS analysis revealed that ethanol extracts of E. capensis contained 50 compounds, of which 16 are terpenes belonging to diterpenoid, ergosterol, sesquiterpenoid, and steroid chemical classes. Conversely, acetone extracts identified thirty-three compounds, of which nine are terpenes (belonging to classes diterpenoid, sesquiterpenoid, and triterpenoid), and one is a phenol (cholesterol). The two members of the genus Turraea, T. floribunda, and T. obtusifolia, recorded minor activities in the antifeedant testing against the test insects. The presence of different chemical classes of compounds such as diterpenoids, flavonoids, limonoids, and terpenoids in some Turraea spp. have been associated with insecticidal activities in previous studies by Essoung et al. [56]; Ndung’u et al. [68]; Udenigwe et al. [69]; Yuan et al. [70]; Xu et al. [71]; and Zanin et al. [72]. Chemical groups other than phenols and terpenes, which have been recorded to have insecticidal, antifeedant, and insect repellent activities, have also been identified in the current study. For example, 9,12-otadecadienoic acid (Z,Z)- present in all T. obtusifolia extracts was reported to have insect-repellent properties in the study by Paulpriya et al. [59].

4. Materials and Methods

4.1. Antifeedant and Insecticidal Analysis

4.1.1. Sample Preparations

Leaves were dried under shade at room temperature (25 °C), then ground into a fine powder using an electric grinder. Extraction was carried out according to the procedures of Warthen et al. [73], with some slight modifications. Ten grams of each powdered sample were extracted in 100 mL of water, acetone, and ethanol separately for 72 h at room temperature. After extraction, the solutions were filtered through Whatman No.40 filter paper, and the solvents were removed using a rotary evaporator. Methanol was used to dissolve the organic residues, where 0.5% and 1.0% solutions were prepared for each sample.

4.1.2. Insects Selection and Rearing

S. frugiperda and P. xylostella second instar larvae strains (between 3 to 7 days old) were obtained from the Agricultural Research Council- Vegetable and Ornamental Plants (ARC- VOPI) in Pretoria, where they were reared, and the information on their age was also obtained.

4.1.3. Repellence Bioassay

The repellence bioassay of the plant samples was assessed using Standard Method Number 3, described by McDonald et al. [74], with some modifications. Repellence tests were conducted using Whatman No.40 filter papers as opposed to the strips of aluminum foil laminated to 40 lb. kaft paper, as described in the study by McDonald et al. [74]. The substrata were prepared by cutting a filter paper in half and placing it in 0.5% and 1.0% solutions of the plant extracts for 1 min, and then allowing it to air dry at room temperature overnight. Each half of the treated disk was attached lengthwise, edge to edge, to an untreated half-disk of the filter paper with cellulose tape and placed in a petri dish (Figure 1A,B). To avoid cannibalism in a petri dish, five larvae of each insect were placed in the middle of each filter paper circle and covered. For five hours, at hourly intervals, individuals that settled on each half of the filter paper disk were counted, and the experimental design was run once. The average of the counts was converted to express the percentage repulsion (PR) as follows:

PR = 2 × (C − 50)

(1)

where C is the percentage of insects on the untreated half of the disk. Positive percentage repulsion values expressed repellence, and negative percentage repulsion values expressed attractancy. The averages of the percentage repulsion were then assigned different classes using the scale as follows [75] (

Table 17. Scale used to assign different classes of percentage repulsion values [75].

Class	Percentage Repulsion
0	>0.01 to <0.1
I	0.1–20
II	20.1–40
III	40.1–60
IV	60.1–80
V	80.1–100

):

4.1.4. Feeding Deterrence Test

The potency of the feeding deterrence effect of plant leaf extracts against S. frugiperda and P. xylostella was determined by using the leaf disk bioassay. Maize and cabbage leaves were used as the test food for S. frugiperda and P. xylostella, respectively. The leaves were soaked in either water only (control leaf disks K) or in a 1% plant extract solution of aqueous, acetone, and ethanol separately (treated leaf disks E). The leaf disks (Figure 2A,B) were allowed to air dry at room temperature for about 30 min and weighed before they were presented to the larvae in petri dishes for 24 h, during which they were serving as the sole food source. The feeding behaviour of the larvae was recorded under three different conditions: (1) pure food, which comprised two control leaves (KK) (control test); (2) food with one control leaf (K) and one treated leaf (E) (choice test); and (3) food with two treated leaves (EE) (no choice test). After 24 h, the remaining leaves were reweighed, and mean percentages of feeding deterrence (FD) were calculated for each plant extract based on the weight of leaves before and after the tests. FD was calculated as follows:

FD = (C − T/C + T) × 100

(2)

C = weight of control leaves; T = weight of treated leaves.

After the FD values were calculated, three coefficients for the feeding deterrent activity from all three tests for each plant extract were calculated as follows [75]:

1.

Absolute deterrence coefficient

A = (KK − EE/KK + EE) × 100

(3)

2.

Relative deterrence coefficient

R = (K − E/K + E) × 100

(4)

3.

Total deterrence coefficient

T = A + R

(5)

Values of the total deterrence coefficient (A) served as an index of the feeding deterrence activity which was expressed on a scale between 0 and 200. Plant extracts with a total deterrence coefficient of between 150–200 were marked ++++; 100–150, +++; 50–100, ++, and 0–50 + [75].

4.1.5. Topical Application Bioassay

The topical treatment assay tested the direct contact toxicity of the plant extracts, using Standard Method Number 1 described by McDonald et al. [74] with some modifications. Plant extract solutions of 0.5% and 1% were used for this test. Larvae were chilled for 10 min instead of being anesthetized with carbon dioxide in a Buchner funnel for about 5 min, as described in the study by McDonald et al. [74]. The immobilized larvae were picked up individually with forceps. Ten microliters of each plant extract solution were applied to the dorsum of each larva. Five larvae were treated at each dose and then transferred to a petri dish. After 24 h, the larvae were examined, and those that did not respond to gentle touch were considered dead. The number of dead larvae was recorded, and corrected mortality rates were calculated using the formula:

Percent larval mortality = (number of dead larvae/total number of treated larvae) × 100

(6)

Probit analysis [76] was used to analyse concentration-mortality data.

4.2. Gas Chromatography-Mass Spectrometry (GC-MS) Analysis

GC-MS analysis was used to identify chemical compounds present in all five selected Meliaceae species. The patterns of the mass spectra fragmentation and their retention indices were compared with the ones stored in the computer library to identify the chemical components found in the plant extracts [77].

4.2.1. Sample Preparation

One gram of powdered samples was extracted in acetone and ethanol for 24 h at room temperature. The extracts were centrifuged at 13,000× g rpm for 10 min at 10 °C. Whatman No.1 filter paper was used to filter the solutions, and a rotary evaporator was used to evaporate or concentrate the solvents. One milliliter of methanol was used to dissolve the organic residues. The solutions were transferred into dark amber vials using syringe filters.

4.2.2. Gas Chromatography-High-Resolution-Time-of-Flight Mass Spectrometry (GC-HRTOF- MS) Analyses

The samples were analysed on the GC-HRTOF- MS system equipped with an Agilent 7890A gas chromatograph (Agilent Technologies, Inc., Wilmington, DE, USA). This system operates in high-resolution, equipped with a Gerstel MPS multipurpose autosampler (Gerstel Inc., Germany) and capillary column (Rxi- 5 ms- 30 m × 0.25 mm ID × 0.25 µm). For each plant extract, a volume of 1 µL was injected in a spitless mode. The program was started at 70 °C, held for 0.5 min, ramped at 10 °C/min to 150 °C, held for 2 min, ramped at 10 °C/min to 330 °C, and held for 3 min for the column to bake out. The samples were analysed at an MS data acquisition rate of 13 spectra/s, m/z range of 30–1000, electron ionization at 70 eV, ion source temperature was set at 250 °C, and the system extraction frequency was set at 1.25 kHz. Solvent blanks were also used to observe for contamination and impurities. Compounds were identified by matching the generated spectra with the NIST, Mainlib, and Feihn reference library databases on ChromaTOF-HRT^® (LECO Corporation, St. Joseph, MI, USA). Subsequent retention time alignment, matched filtration, peak picking, detection, and matching were conducted on a data station equipped with the ChromaTOF-HRT^® software (LECO Corporation, St. Joseph, MI, USA). Parameters adopted for processing included a signal-to-noise ratio (S/N) of 100, a similarity match above 70%, and data presented in Table 7, Table 8, Table 9, Table 10, Table 11, Table 12, Table 13, Table 14, Table 15 and Table 16 representing only compounds occurring at least twice in triplicate injections. The collected GC-HRTOF-MS dataset was converted to mzML format using the LECO ChromaTOF-HRT software and then processed (peak picking and alignment) on the XCMS open-source tool.

5. Conclusions

Meliaceae species are abundant large tree species, so they would be suitable to supply very large-scale production of botanical insecticides; thus, their potential use in controlling insect pests is promising. This study provides potential evidence that further confirms the findings of many previous reports that Meliaceae members can be used as repellents, insecticides, and antifeedants to control S. frugiperda and P. xylostella insects, two of the most important agricultural pests that mostly attack crops which form part of the primary staple food. All extracts of the five evaluated species indicated repellence to the S. frugiperda and P. xylostella larvae, except for the ethanolic extracts of T. floribunda, which showed attraction to both the larvae. All extracts evaluated exhibited feeding deterrence to the S. frugiperda and P. xylostella larvae to some extent, except for the ethanol extracts of T. floribunda, which had inert antifeeding compounds. Aqueous extracts of E. capensis and T. floribunda were more toxic to the S. frugiperda larvae, and all extracts of M. azedarach were more toxic to the P. xylostella larvae. The GC-MS analysis results strongly support the insecticidal activities of the evaluated extracts as the two most well-known groups, phenols and terpenes, known to have insecticidal and antifeedant properties, were present in all the plant extracts. Therefore, this further corroborates the recorded traditional uses of these plants as insecticides and antifeedants. Plants that have indicated the most promising results are E. capensis, T. floribunda, and T. obtusifolia. These plants should be subjected to further quantitative phytochemical studies focusing on isolating and identifying active compounds rather than simply screening the plant extracts for insecticidal and antifeedant activity, as plant extracts may contain many compounds along with those that may cause negative side effects and toxicity. Further research should also be conducted regarding their safe use and non-target effects, and to determine if they can maintain yield at comparable levels to synthetic pesticides. Field trial evaluations of insecticidal and antifeedant plant extracts may also need to be undertaken to assess their impact on crop yield and damage and evaluate insect resistance issues in comparison to synthetic pesticides. This study’s results are significant as they will generate new and alternative natural products that can help improve biological effectiveness, lower residuals, increase nontoxic agricultural products, and decrease their presence in foods.