Submit to Special Issue Submit Abstract to Special Issue Review for Molecules Propose a Special Issue

Journal Menu

Journal Browser

Chemical Composition and Bioactivities of Essential Oils, 2nd Edition

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Natural Products Chemistry".

Deadline for manuscript submissions: 31 December 2024 | Viewed by 16590

Share This Special Issue

Special Issue Editor

Dr. Manuela Labbozzetta

E-Mail Website
Guest Editor

Department of Biological, Chemical and Pharmaceutical Science and Technology (STEBICEF), University of Palermo, Palermo, Italy
Interests: pharmacology; chemotherapy; multidrug resistance; natural products; pharmacognosy and phytotherapy
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The discovery of natural plant-based products is rightly recognized as a milestone in the history of health care, and their introduction into the market in combination with synthetic medicines has resolved many health concerns. As a result, the extraction of plant secondary metabolites such as essential oils (EOs) through steam or hydro-distillation processes has witnessed significant progress over the years. EOs are a complex mixture of various chemical compounds; primarily characterized by volatility, aroma, and low molecular weight. The diverse biological properties of EOs arise from the differences in their chemical constitution and structure. EOs play important roles in defense against external agents and participate in signal transduction pathways. The biological properties of EOs are widely documented by a large body of literature, demonstrating their antitumor, antibioceptive, antiviral, antiphlogistic and antimicrobial activity in vitro. Furthermore, essential oils contain several chemical classes of compounds whose heterogeneity of active moieties can help prevent the development of drug resistance. Therefore, due to their low toxicity, good pharmacokinetics and multitarget action, EOs represent important alternatives to synthetic chemicals as promising drugs for therapeutic use.

The purpose of the 2nd edition of this Special Issue, entitled "Chemical composition and bioactivity of essential oils", is to continue to provide an update on the phytochemical composition of plant extracts and to analyze the bioactivity of essential oils or their components in different models, in vitro and/or in vivo, also taking into account the possibility of using new site-specific EO delivery strategies.

Major topics of interest include, but are not limited to, the following:

Extraction, isolation and characterization of bioactive compounds from plant extracts;
Evaluation of the antioxidant, antitumor and antimicrobial activity of essential oils or their constituents;
Evaluation of the activity of essential oils in multi-drug resistance models;
Evaluation of the benefits of using emerging technologies for the efficient delivery of EOs into target cells also in combination with conventional chemotherapy drugs.

Dr. Manuela Labbozzetta
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

bioactive natural compounds
essential oils
chemical characterization
the essential oil mechanism of action
the biological activities in vitro and in vivo
antitumor
antimicrobials
antioxidant
EOs delivery strategies

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (9 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

19 pages, 2882 KiB

Open AccessArticle

Biological Potential and Essential Oil Profile of Two Wild Apiaceae Species from Algeria (Daucus carota L. and Foeniculum vulgare Mill.): Larvicidal and Antibacterial Effects

by Aicha Khemili, Djamel Bensizerara, Haroun Chenchouni, Rachid Chaibi, Nadjwa Aissani, Desiye Tesfaye Tegegne, El-Sayed R. El-Sayed and Antoni Szumny

Molecules 2024, 29(19), 4614; https://doi.org/10.3390/molecules29194614 - 28 Sep 2024

Viewed by 1423

Abstract

Infectious diseases, including vector-borne and antibiotic-resistant infections, present significant global health challenges, necessitating the exploration of natural alternatives for disease control. In this study, we investigated the essential oil (EO) profile as well as larvicidal and antibacterial properties of two wild Apiaceae species used in Algeria: Daucus carota L. (DCEO) and Foeniculum vulgare Mill. (FVEO). EO was extracted from the aerial parts by steam distillation and analyzed using Gas Chromatography Mass Spectrometry (GC/MS). Major constituents identified in DCEO were geranyl acetate (50.07%) and elemicin (10.77%), while FVEO contained estragole (24.93%), fenchone (20.20%), and α-phellandrene (17.96%). Both EOs were highly effective towards Culex pipiens larvae, with low LC₅₀ values of 30.6 ± 1.06 ppm for DCEO and 34.7 ± 1.06 ppm for FVEO, indicating their potential as bioinsecticides due to their bioactivity and bioavailability. Additionally, the two Eos demonstrated moderate antibacterial efficacy against gram-positive bacteria, Staphylococcus aureus ATCC 25923 and Staphylococcus aureus MRSA ATCC 43300, respectively, with DCEO showing MIC values of 10 and 20 mg/mL, respectively, and FVEO exhibiting MIC values > 20 mg/mL. However, both EOs showed limited effectiveness against gram-negative bacteria, Escherichia coli ATCC 25922 and Klebsiella pneumonia ATCC 700603. These results highlight the potential applications of DCEO and FVEO as natural bioinsecticides and antibacterial agents, offering promising avenues for further research and development in pest control and food preservation. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Figure 1

15 pages, 2332 KiB

Open AccessArticle

Repellency, Toxicity, and Chemical Composition of Plant Essential Oils from Myrtaceae against Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera Liviidae)

by Yi-Jie Li, Tian-Ao Liu, Hang Zhao, Yang Han, Bing-Hai Lou, Cui-Yun Lei, Ya-Qin Song and Hong-Bo Jiang

Molecules 2024, 29(14), 3390; https://doi.org/10.3390/molecules29143390 - 18 Jul 2024

Viewed by 1166

Abstract

Diaphorina citri Kuwayama (D. citri) is one of the major pests in the citrus industry, which spreads Citrus Huanglongbing disease. It has developed resistance to chemical insecticides. Therefore, searching for greener solutions for pest management is critically important. The main aim of this study was to evaluate the repellent and insecticidal efficacy of essential oils (EOs) from four species of Myrtaceae plants: Psidium guajava (PG), Eucalyptus robusta (ER), Eucalyptus tereticornis (ET), and Baeckea frutescens (BF) against D. citri and to analyze their chemical compositions. GC-MS analysis was performed, and the results indicated that the EOs of PG, ER, ET, and BF were rich in terpenoids, ketones, esters, and alcohol compounds. The repellent rate of all four EOs showed that it decreased with exposure time but increased with the concentration of EOs from 80.50% to 100.00% after treating D. citri for 6 h with four EOs at 100% concentration and decreased to 67.71% to 85.49% after 24 h of exposure. Among the compounds from the EOs tested, eucalyptol had the strongest repellent activity, with a 24 h repellency rate of 100%. The contact toxicity bioassay results showed that all EOs have insecticidal toxicity to D. citri; the LC50 for nymphs was 36.47–93.15 mL/L, and for adults, it was 60.72–111.00 mL/L. These results show that when PG is used as the reference material, the ER, ET, and BF EOs have strong biological activity against D. citri, which provides a scientific basis for the further development of plant-derived agrochemicals. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Figure 1

23 pages, 2653 KiB

Open AccessArticle

The Repellent Capacity against Sitophilus zeamais (Coleoptera: Curculionidae) and In Vitro Inhibition of the Acetylcholinesterase Enzyme of 11 Essential Oils from Six Plants of the Caribbean Region of Colombia

by Amner Muñoz-Acevedo, María C. González, Jesús E. Alonso and Karen C. Flórez

Molecules 2024, 29(8), 1753; https://doi.org/10.3390/molecules29081753 - 12 Apr 2024

Viewed by 1088

Abstract

The repellent capacity against Sitophilus zeamais and the in vitro inhibition on AChE of 11 essential oils, isolated from six plants of the northern region of Colombia, were assessed using a modified tunnel-type device and the Ellman colorimetric method, respectively. The results were as follows: (i) the degree of repellency (DR) of the EOs against S. zeamais was 20–68% (2 h) and 28–74% (4 h); (ii) the IC₅₀ values on AChE were 5–36 µg/mL; likewise, the %inh. on AChE (1 µg/cm³ per EO) did not show any effect in 91% of the EO tested; (iii) six EOs (Bursera graveolens—bark, B. graveolens—leaves, B. simaruba—bark, Peperomia pellucida—leaves, Piper holtonii (1b*)—leaves, and P. reticulatum—leaves) exhibited a DR (53–74%) ≥ C⁺ (chlorpyrifos—61%), while all EOs were less active (8–60-fold) on AChE compared to chlorpyrifos (IC₅₀ of 0.59 µg/mL). Based on the ANOVA/linear regression and multivariate analysis of data, some differences/similarities could be established, as well as identifying the most active EOs (five: B. simaruba—bark, Pep. Pellucida—leaves, P. holtonii (1b*)—leaves, B. graveolens—bark, and B. graveolens—leaves). Finally, these EOs were constituted by spathulenol (24%)/β-selinene (18%)/caryophyllene oxide (10%)—B. simaruba; carotol (44%)/dillapiole (21%)—Pep. pellucida; dillapiole (81% confirmed by ¹H-/¹³C-NMR)—P. holtonii; mint furanone derivative (14%)/mint furanone (14%)—B. graveolens—bark; limonene (17%)/carvone (10%)—B. graveolens—leaves. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Figure 1

17 pages, 2704 KiB

Open AccessArticle

Pinus koraiensis Essential Oil Attenuates the Pathogenicity of Superbacteria by Suppressing Virulence Gene Expression

by Ji-Hee Kim, Young-Hoi Kim, Bog-Im Park, Na-Young Choi and Kang-Ju Kim

Molecules 2024, 29(1), 37; https://doi.org/10.3390/molecules29010037 - 20 Dec 2023

Cited by 2 | Viewed by 1238

Abstract

In the quest to combat infections attributable to antibiotic-resistant superbacteria, an essential oil derived from the needles of Pinus koraiensis Sieb. et Zucc. (PKEO) has emerged as a promising solution. In this study, we demonstrate that PKEO can be used to inhibit the growth, glucose metabolite acidogenicity, and biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA). Quantitative PCR analysis provided direct evidence that PKEO reduces the mRNA expression of the accessory gene regulator A (agrA) and staphylococcal accessory regulator A (sarA), thereby indicating its inhibitory effect on pathogenic regulatory genes. Chromatographic analyses of PKEO identified terpene hydrocarbons as prominent essential oil constituents. These compounds, notably α-pinene, limonene, and β-caryophyllene, have been established to have antimicrobial properties. Our findings indicate that an oil derived from P. koraiensis can effectively combat antibiotic-resistant strains by disrupting the pathogenicity regulatory system, thereby establishing PKEO as a promising candidate for the treatment of MRSA infections. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Figure 1

12 pages, 2060 KiB

Open AccessArticle

Exploring the Larvicidal and Repellent Potential of Taurus Cedar (Cedrus libani) Tar against the Brown Dog Tick (Rhipicephalus sanguineus sensu lato)

by Samed Koc, Zeynep Nur Gultekin, Sevval Kahraman, Aysegul Cengiz, Burak Polat, Cansu Caliskan, Tolga Yildirim, Ozge Tufan-Cetin and Huseyin Cetin

Molecules 2023, 28(23), 7689; https://doi.org/10.3390/molecules28237689 - 21 Nov 2023

Cited by 2 | Viewed by 1657

Abstract

This study investigated the potential acaricidal and repellent effects of tar obtained from the Lebanon cedar (Cedrus libani A. Rich.) against the brown dog tick species Rhipicephalus sanguineus sensu lato Latreille (Acari: Ixodidae). The goal was to find an alternative, safe, and effective way to eliminate ticks. Tar is traditionally extracted from cedar trees in the Antalya region of Türkiye. The composition of the tar is primarily characterized by a diverse mixture of terpenes, with β-himachalene (29.16%), α-atlantone (28.7%), ar-turmerone (8.82%), longifolene-(V4) (6.66%), α-himachalene (5.28%), and β-turmerone (5.12%) emerging as the predominant constituents. The toxic effects of tar on tick larvae were studied through larval immersion tests (LIT), and its repellent activity was evaluated using a new larval repellent activity test (LRAT). The results revealed significant acaricidal effects, with mortality rates of 77.7% and 82.2% for the Konyaalti and Kepez strains of the brown dog tick, respectively, in response to a 1% concentration of tar. LC₅₀ and LC₉₀ values were determined as 0.47% and 1.52% for the Kepez strain and 0.58% and 1.63% for the Konyaalti strain, respectively. When comparing the repellent effect of tar to the widely used synthetic repellent DEET, repellency rates of up to 100% were observed. As a result, this study establishes, for the first time, the larvicidal and repellent effects of C. libani tar on ticks. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Graphical abstract

22 pages, 11949 KiB

Open AccessArticle

Potential of Natural Phenolic Compounds as Antimicrobial Agents against Multidrug-Resistant Staphylococcus aureus in Chicken Meat

by Alaa Eldin M. A. Morshdy, Karima M. E. Abdallah, Heba E. Abdallah, Fahad D. Algahtani, Mohamed Tharwat Elabbasy, Suleman Atique, Khursheed Ahmad, Mohammad A. A. Al-Najjar, Hossam M. Abdallah and Abdallah Fikry A. Mahmoud

Molecules 2023, 28(18), 6742; https://doi.org/10.3390/molecules28186742 - 21 Sep 2023

Cited by 4 | Viewed by 2059

Abstract

Staphylococcus aureus is one of the most widespread foodborne bacteria that cause high morbidity, mortality, and economic loss, primarily if foodborne diseases are caused by pathogenic and multidrug-resistant (MDR) strains. This study aimed to determine the prevalence of S. aureus in chicken meat in Egyptian markets. Thus, this study might be the first to assess the efficiency of different natural phenolic compounds as novel antibacterial agents against MDR S. aureus pathogens isolated from raw chicken meat in the Egyptian market. The incidence and quantification of pathogenic S. aureus were detected in retail raw chicken meat parts (breast, thigh, fillet, and giblets). In total, 73 out of 80 (91.3%) of the chicken meat parts were contaminated, with S. aureus as the only species isolated. Of the 192 identified S. aureus isolates, 143 were coagulase-positive S. aureus and 117 isolates were MDR (81.8%, 117/143). Twenty-two antibiotic resistance profile patterns were detected. One strain was randomly selected from each pattern to further analyze virulence and resistance genes. Extracted DNA was assessed for the presence of antibiotic-resistance genes, i.e., vancomycin-resistance (vanA), aminoglycosides-resistance (aacA–aphD), apramycin-resistance (apmA), and methicillin-resistance (mecA), penicillin-resistance (blaZ), and virulence genes staphylococcal enterotoxins (sea and seb), Panton–Valentine leucocidin (pvl), clumping factor A (clfA), and toxic shock syndrome toxin (tst). Clustering analyses revealed that six S. aureus strains harbored the most virulence and resistance genes. The activity of hydroquinone was significantly higher than thymol, carvacrol, eugenol, and protocatechuic acid. Therefore, phenolic compounds, particularly hydroquinone, could potentially alternate with conventional antibiotics against the pathogenic MDR S. aureus inhabiting raw chicken meat. Hence, this study indicates that urgent interventions are necessary to improve hygiene for safer meat in Egyptian markets. Moreover, hydroquinone could be a natural phenolic compound for inhibiting foodborne pathogens. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Graphical abstract

16 pages, 907 KiB

Open AccessArticle

Antioxidant and Antibacterial Activity of Mexican Oregano Essential Oil, Extracted from Plants Occurring Naturally in Semiarid Areas and Cultivated in the Field and Greenhouse in Northern Mexico

by Ruben I. Marin-Tinoco, Angie Tatiana Ortega-Ramírez, Maricela Esteban-Mendez, Oscar Silva-Marrufo, Laura E. Barragan-Ledesma, Luis M. Valenzuela-Núñez, Edwin A. Briceño-Contreras, Maria A. Sariñana-Navarrete, Abelardo Camacho-Luis and Cayetano Navarrete-Molina

Molecules 2023, 28(18), 6547; https://doi.org/10.3390/molecules28186547 - 9 Sep 2023

Cited by 5 | Viewed by 2365

Abstract

In recent years, the determination of the antioxidant and antibacterial activity of essential oils in wild plants, such as Mexican oregano (Lippia graveolens Kunth), has become increasingly important. The objective was to compare the antioxidant and antibacterial activity of Mexican oregano essential oil obtained from plants occurring naturally in semiarid areas (Wild1 and Wild2), and those cultivated in the field (CField) and greenhouse (CGreenhouse) in northern Mexico. The Mexican oregano essential oil extraction was performed using the hydrodistillation method, the antioxidant activity was determined using the ABTS method, and the antibacterial activity was assessed through bioassays under the microwell method at nine different concentrations. The aim was to determine the diameter of the inhibition zone and, consequently, understand the sensitivity level for four bacterial species. The results revealed an antioxidant activity ranging from 90% to 94% at the sampling sites, with Wild1 standing out for having the highest average antioxidant activity values. Likewise, six out of the nine concentrations analyzed showed some degree of sensitivity for all the sampling sites. In this regard, the 25 µL mL⁻¹ concentration showed the highest diameter of inhibition zone values, highlighting the Wild2 site, which showed an average diameter greater than 30 mm for the four bacteria tested. Only in the case of S. typhi did the CGreenhouse site surpass the Wild2, with an average diameter of the inhibition zone of 36.7 mm. These findings contribute to the search for new antioxidant and antibacterial options, addressing the challenges that humanity faces in the quest for opportunities to increase life expectancy. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Graphical abstract

15 pages, 3599 KiB

Open AccessArticle

Yield, Chemical Composition and Bioactivity of Essential Oils from Common Juniper (Juniperus communis L.) from Different Spanish Origins

by Luis Saúl Esteban, Irene Mediavilla, Virginie Xavier, Joana S. Amaral, Tânia C. S. P. Pires, Ricardo C. Calhelha, César López and Lillian Barros

Molecules 2023, 28(11), 4448; https://doi.org/10.3390/molecules28114448 - 30 May 2023

Cited by 8 | Viewed by 2538

Abstract

Essential oils (EOs) obtained from Juniperus communis L. are frequently used in the production of bioproducts. However, there are no studies regarding industrial crops’ production, allowing for better control of the quality and production of juniper EOs. To select the plant material for developing future crops of this species in northern Spain, four locations where this shrub species grows in the wild were selected and samples of both genera were collected. The EOs were obtained by steam distillation, and their chemical composition and bioactivity were evaluated. The results showed that the yield of EOs from male and female samples were within the usual reported ranges, varying between 0.24 and 0.58% (dry basis, d.b.). However, limonene content in three locations varied between 15 and 25%, which is between 100% and 200% higher than the values usually reported for other European countries. The antibacterial activity was determined by broth microdilution and showed that gram-positive bacteria were more susceptible to the tested EOs since, in general, lower MIC values were obtained compared to gram-negatives. The EOs from location 1 (L1F) and 2 (L2M) inhibited the growth of six out of the eight clinical strains tested. Samples from location 1 were particularly effective, exhibiting MBC against two gram-negative (E. coli and P. mirabilis) and one gram-positive bacteria (E. faecalis). Moreover, the majority of the EOs tested showed anti-inflammatory activity. Cytotoxic effect has been demonstrated in tumor cell lines, with the best results observed against gastric carcinoma (AGS) cells (GI₅₀ between 7 to 77 µg/mL). Although generally presenting higher GI₅₀, most samples also inhibited the growth of non-tumoral cells, particularly hepatocytes (PLP2 cells). Therefore, its use for their anti-proliferative activity should consider specific conditions to avoid damaging normal cells. Finally, the results and conclusions obtained led to the selection of the female shrubs from location 1 (L1F) as the plant material to be propagated in order to produce plants for a future juniper crop. Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Figure 1

9 pages, 721 KiB

Open AccessCommunication

Essential Oil Composition of Grindelia squarrosa from Southern Idaho

by Ambika Poudel, Noura S. Dosoky, Prabodh Satyal, Kathy Swor and William N. Setzer

Molecules 2023, 28(9), 3854; https://doi.org/10.3390/molecules28093854 - 2 May 2023

Cited by 2 | Viewed by 1978

Abstract

Grindelia squarrosa is an arid lands herb that has been used in Native American traditional medicine, is a potential source of pharmacologically active compounds, and has been explored as a source of biofuel. The purpose of this work was to examine the essential oil composition of G. squarrosa from southern Idaho. Gas chromatographic methods revealed the essential oil of G. squarrosa var. serrulata to be rich in monoterpenoids, α-pinene (21.9%), limonene (17.1%), terpinolene (10.6%), and borneol (6.5%). The essential oil composition of G. squarrosa from Idaho is similar to that previously reported from specimens collected from Montana and confirms the volatile phytochemistry of plants growing in North America. The major essential oil components were screened for antimicrobial activity against respiratory and dermal pathogens. (–)-β-Pinene showed strong antibacterial activity against Streptococcus pneumoniae (MIC 39.1 μg/mL) and (–)-borneol showed strong activity against Staphylococcus aureus (MIC 78.1 μg/mL). Full article

(This article belongs to the Special Issue Chemical Composition and Bioactivities of Essential Oils, 2nd Edition)

► Show Figures

Journal Menu

Journal Browser

Chemical Composition and Bioactivities of Essential Oils, 2nd Edition

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI