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Discovery of Active Ingredients from Natural Products

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

Deadline for manuscript submissions: closed (30 September 2019) | Viewed by 118751

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Guest Editor
Transdisciplinary Science and Engineering Program, Graduate School of Advanced Science and Engineering, Hiroshima University, Hiroshima 739-8529, Japan
Interests: natural products; agricultural chemistry; weed science
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Natural products are chemical compounds or substances originating from living organisms and can also be prepared via chemical synthesis. Natural products have been broadly utilized in the development of dietary supplements, medicines and pharmaceutics, cosmetics, and foods. However, identifying and determining active ingredients from natural products are prerequisites. This Special Issue welcomes research and review articles searching for active constituents from natural products, including methods of isolation and identification, and the development of protocols to regulate biological activities. Active ingredients involved in agricultural, food, medicinal, and pharmaceutical chemistry are cordially invited.

Prof. Dr. Tran Dang Xuan
Guest Editor

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Keywords

  • Natural products
  • Phytochemicals
  • Biological activities
  • Analytical instruments
  • Isolation and Purification

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Published Papers (16 papers)

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Research

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12 pages, 5010 KiB  
Article
α-Glucosidase and Pancreatic Lipase Inhibitory Activities of Diterpenes from Indian Mango Ginger (Curcuma amada Roxb.) and Its Derivatives
by Yuri Yoshioka, Naori Yoshimura, Shinichi Matsumura, Hiroto Wada, Maya Hoshino, Shouhei Makino and Masanori Morimoto
Molecules 2019, 24(22), 4071; https://doi.org/10.3390/molecules24224071 - 10 Nov 2019
Cited by 14 | Viewed by 4285
Abstract
Enzymatic inhibitions of crude extracts and their constituents from Zingiberaceae against both rat intestinal α-glucosidase and porcine pancreatic lipase were investigated. Structure–activity relationships using their derivatives were also investigated. The rhizomes extract of mango ginger, Curcuma amada showed remarkable inhibitory activity in the [...] Read more.
Enzymatic inhibitions of crude extracts and their constituents from Zingiberaceae against both rat intestinal α-glucosidase and porcine pancreatic lipase were investigated. Structure–activity relationships using their derivatives were also investigated. The rhizomes extract of mango ginger, Curcuma amada showed remarkable inhibitory activity in the screening test. Two natural labdane diterpenes 1 and 2 and a drimane sesquiterpene 3 were major constituents isolated from this hexane extract. Among them, (E)-labda-8(17),12-diene-15,16-dial (1) was the most prominent compound and showed inhibitory activity against both α-glucosidase and lipase. Derivatives 410 from compound 1 were prepared and evaluated using inhibitory assays with these enzymes. The reduced derivative 4 maintained α-glucosidase inhibitory activity, but had decreased pancreatic lipase inhibitory activity compared with parent compound 1. Other tested derivatives of compound 1, including acetates 57 and oxidative derivatives 8–10, had very weak α-glucosidase inhibitory activity. Most of these compounds showed moderate pancreatic lipase inhibitory activity. However, only sesquiterpene albicanal (3) showed drastically decreased pancreatic lipase activity compared with 1. These findings suggested that molecular size was essential for enzymatic inhibitory activities of these compounds. These results demonstrated that mango ginger may be useful for the prevention of obesity and being overweight. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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13 pages, 2043 KiB  
Article
Kurarinone from Sophora Flavescens Roots Triggers ATF4 Activation and Cytostatic Effects Through PERK Phosphorylation
by Sakiko Nishikawa, Yuka Itoh, Muneshige Tokugawa, Yasumichi Inoue, Ken-ichi Nakashima, Yuka Hori, Chiharu Miyajima, Kou Yoshida, Daisuke Morishita, Nobumichi Ohoka, Makoto Inoue, Hajime Mizukami, Toshiaki Makino and Hidetoshi Hayashi
Molecules 2019, 24(17), 3110; https://doi.org/10.3390/molecules24173110 - 27 Aug 2019
Cited by 11 | Viewed by 4664
Abstract
In response to cellular stresses, activating transcriptional factor 4 (ATF4) regulates the expression of both stress-relieving genes and apoptosis-inducing genes, eliciting cell fate determination. Since pharmacological activation of ATF4 exerts potent anti-tumor effects, modulators of ATF4 activation may have potential in cancer therapy. [...] Read more.
In response to cellular stresses, activating transcriptional factor 4 (ATF4) regulates the expression of both stress-relieving genes and apoptosis-inducing genes, eliciting cell fate determination. Since pharmacological activation of ATF4 exerts potent anti-tumor effects, modulators of ATF4 activation may have potential in cancer therapy. We herein attempted to identify small molecules that activate ATF4. A cell-based screening to monitor TRB3 promoter activation was performed using crude drugs used in traditional Japanese Kampo medicine. We found that an extract from Sophora flavescens roots exhibited potent TRB3 promoter activation. The activity-guided fractionation revealed that kurarinone was identified as the active ingredient. Intriguingly, ATF4 activation in response to kurarinone required PKR-like endoplasmic reticulum kinase (PERK). Moreover, kurarinone induced the cyclin-dependent kinase inhibitor p21 as well as cytostasis in cancer cells. Importantly, the cytostatic effect of kurarinone was reduced by pharmacological inhibition of PERK. These results indicate that kurarinone triggers ATF4 activation through PERK and exerts cytostatic effects on cancer cells. Taken together, our results suggest that modulation of the PERK-ATF4 pathway with kurarinone has potential as a cancer treatment. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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12 pages, 1398 KiB  
Article
Antispasmodic Activity of Prenylated Phenolic Compounds from the Root Bark of Morus nigra
by Zoofishan Zoofishan, Norbert Kúsz, Attila Csorba, Gábor Tóth, Judit Hajagos-Tóth, Anna Kothencz, Róbert Gáspár and Attila Hunyadi
Molecules 2019, 24(13), 2497; https://doi.org/10.3390/molecules24132497 - 8 Jul 2019
Cited by 15 | Viewed by 5282
Abstract
Black mulberry is a widely acknowledged ancient traditional medicine. Its extract and constituents have been reported to exert various bioactivities including antimicrobial, hypotensive, analgesic etc. effects. While black mulberry preparations are also used as antispasmodic agents in folk medicine, no related studies are [...] Read more.
Black mulberry is a widely acknowledged ancient traditional medicine. Its extract and constituents have been reported to exert various bioactivities including antimicrobial, hypotensive, analgesic etc. effects. While black mulberry preparations are also used as antispasmodic agents in folk medicine, no related studies are available on its isolated constituents. Through an extensive chromatographic purification, seven phenolic compounds were isolated from the methanol extract of Morus nigra root bark, including morusin (1), kuwanon U (2), kuwanon E (3), moracin P (4), moracin O (5), albanol A (6), and albanol B (7). A complete NMR signal assignment of moracin P and O was achieved, and related literature errors confusing the identity of moracin derivatives are hereby clarified. Compounds 2, 5 and 7 were identified as strong antispasmodic agents on isolated rat ileum and tracheal smooth muscles, while compound 3, a methoxy derivative of 2, was inactive. Moracin O (5) inhibited the ileal and tracheal smooth muscle contractions with Emax values of 85% and 302 mg, respectively. Those actions were superior as compared with papaverine. Our findings demonstrate that prenylated arylbenzofurans, geranylated flavonoids and Diels-Alder adducts from Morus nigra are valuable antispasmodic agents. Compounds 2, 5 and 7 are suggested as marker compounds for quality control of antispasmodic mulberry preparations. Moracin O (5) is a new lead compound for related drug development initiatives. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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19 pages, 3720 KiB  
Article
Encapsulated Microparticles of (1→6)-β-d-Glucan Containing Extract of Baccharis dracunculifolia: Production and Characterization
by Genice Iurckevicz, Débora Dahmer, Vidiany A. Q. Santos, Vaclav Vetvicka, Aneli M. Barbosa-Dekker, Robert F. H. Dekker, Carlos Ricardo Maneck Malfatti and Mário A. A. da Cunha
Molecules 2019, 24(11), 2099; https://doi.org/10.3390/molecules24112099 - 3 Jun 2019
Cited by 11 | Viewed by 3229
Abstract
β-Glucans are biomacromolecules well known, among other biological activities, for their immunomodulatory potential. Similarly, extracts of Baccharis dracunculifolia also possess biological properties and are used in folk medicine for the treatment of inflammation, ulcers, and hepatic diseases. Microparticles containing (1→6)-β-d-glucan (lasiodiplodan) [...] Read more.
β-Glucans are biomacromolecules well known, among other biological activities, for their immunomodulatory potential. Similarly, extracts of Baccharis dracunculifolia also possess biological properties and are used in folk medicine for the treatment of inflammation, ulcers, and hepatic diseases. Microparticles containing (1→6)-β-d-glucan (lasiodiplodan) and B. dracunculifolia extract were produced and characterized. A 23 factorial design was employed to define the conditions of production of microparticles by atomization. Lasiodiplodan associated with maltodextrin and gum arabic was studied as a matrix material. Microparticles of 0.4 μm mean size and high phenolics content (3157.9 μg GAE/g) were obtained under the optimized conditions. The microparticle size ranged from 0.23 to 1.21 µm, and the mathematical model that best represented the release kinetics of the extract was the Korsmeyer-Peppas model. Diffusional exponent (n) values of 0.64 at pH 7.7 and 1.15 at pH 2.61 were found, indicating particles with a non-Fickian or anomalous transport system, and Super Case II transport, respectively. Thermal analysis indicated that the microparticles demonstrated high thermal stability. The X-ray diffraction analyses revealed an amorphous structure, and HPLC-DAD analysis showed microparticles rich in phenolic compounds: caffeic acid, p-coumaric acid, and catechin. The microparticles obtained comprise a new biomaterial with biological potential for applications in different fields. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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17 pages, 4442 KiB  
Article
The Role of Astragaloside IV against Cerebral Ischemia/Reperfusion Injury: Suppression of Apoptosis via Promotion of P62-LC3-Autophagy
by Yi Zhang, Ying Zhang, Xiao-fei Jin, Xiao-hong Zhou, Xian-hui Dong, Wen-tao Yu and Wei-juan Gao
Molecules 2019, 24(9), 1838; https://doi.org/10.3390/molecules24091838 - 13 May 2019
Cited by 121 | Viewed by 6775
Abstract
Background: Ischemia/reperfusion (I/R) caused by ischemic stroke treatments leads to brain injury, and autophagy plays a role in the pathology. Astragaloside IV is a potential neuroprotectant, but its underlying mechanism on cerebral I/R injury needs to be explored. The objective of this study [...] Read more.
Background: Ischemia/reperfusion (I/R) caused by ischemic stroke treatments leads to brain injury, and autophagy plays a role in the pathology. Astragaloside IV is a potential neuroprotectant, but its underlying mechanism on cerebral I/R injury needs to be explored. The objective of this study is to investigate the neuroprotective mechanism of Astragaloside IV against cerebral I/R injury. Methods: Middle cerebral artery occlusion method (MCAO) and oxygen and glucose deprivation/reoxygenation (OGD/R) method were used to simulate cerebral I/R injury in Sprague-Dawley (SD) rats and HT22 cells, respectively. The neurological score, 2,3,5-Triphe-nyltetrazolium chloride (TTC) staining, and transmission electron microscope were used to detect cerebral damage in SD rats. Cell viability and cytotoxicity assay were tested in vitro. Fluorescent staining and flow cytometry were applied to detect the level of apoptosis. Western blotting was conducted to examine the expression of proteins associated with autophagy. Results: This study found that Astragaloside IV could decrease the neurological score, reduce the infarct volume in the brain, and alleviate cerebral I/R injury in MCAO rats. Astragaloside IV promoted cell viability and balanced Bcl-2 and Bax expression in vitro, reduced the rate of apoptosis, decreased the expression of P62, and increased the expression of LC3II/LC3I in HT22 cells after OGD/R. Conclusions: These data suggested that Astragaloside IV plays a neuroprotective role by down-regulating apoptosis by promoting the degree of autophagy. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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13 pages, 4355 KiB  
Article
Brassinin Represses Invasive Potential of Lung Carcinoma Cells through Deactivation of PI3K/Akt/mTOR Signaling Cascade
by Min Hee Yang, Jong Hyun Lee, Jeong-Hyeon Ko, Sang Hoon Jung, Gautam Sethi and Kwang Seok Ahn
Molecules 2019, 24(8), 1584; https://doi.org/10.3390/molecules24081584 - 22 Apr 2019
Cited by 67 | Viewed by 5789
Abstract
The epithelial–mesenchymal transition (EMT) is a phenomenon that facilitates epithelial cells to acquire invasive potential to induce the initiation the metastatic spread of tumor cells. Here, we determined if brassinin (BSN) can affect the EMT process and deciphered its anti-cancer effects. BSN attenuated [...] Read more.
The epithelial–mesenchymal transition (EMT) is a phenomenon that facilitates epithelial cells to acquire invasive potential to induce the initiation the metastatic spread of tumor cells. Here, we determined if brassinin (BSN) can affect the EMT process and deciphered its anti-cancer effects. BSN attenuated the levels of EMT linked genes and suppressed transforming growth factor beta (TGF-β)-mediated regulation of diverse mesenchymal markers. Additionally, BSN did increase the expression of various epithelial marker proteins in lung cancer cells. TGF-β-induced morphological changes and induction of invasive ability of tumor cells was also found to be abrogated by BSN treatment. Finally, BSN not only suppressed constitutive, but also inducible phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) phosphorylation in tumor cells. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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13 pages, 1692 KiB  
Article
Characterization of Tapeworm Metabolites and Their Reported Biological Activities
by Phurpa Wangchuk, Constantin Constantinoiu, Ramon M. Eichenberger, Matt Field and Alex Loukas
Molecules 2019, 24(8), 1480; https://doi.org/10.3390/molecules24081480 - 15 Apr 2019
Cited by 14 | Viewed by 5582
Abstract
Parasitic helminths infect billions of people, livestock, and companion animals worldwide. Recently, they have been explored as a novel therapeutic modality to treat autoimmune diseases due to their potent immunoregulatory properties. While feeding in the gut/organs/tissues, the parasitic helminths actively release excretory-secretory products [...] Read more.
Parasitic helminths infect billions of people, livestock, and companion animals worldwide. Recently, they have been explored as a novel therapeutic modality to treat autoimmune diseases due to their potent immunoregulatory properties. While feeding in the gut/organs/tissues, the parasitic helminths actively release excretory-secretory products (ESP) to modify their environment and promote their survival. The ESP proteins of helminths have been widely studied. However, there are only limited studies characterizing the non-protein small molecule (SM) components of helminth ESP. In this study, using GC-MS and LC-MS, we have investigated the SM ESP of tapeworm Dipylidium caninum (isolated from dogs) which accidentally infects humans via ingestion of infected cat and dog fleas that harbor the larval stage of the parasite. From this D. caninum ESP, we have identified a total of 49 SM (35 polar metabolites and 14 fatty acids) belonging to 12 different chemotaxonomic groups including amino acids, amino sugars, amino acid lactams, organic acids, sugars, sugar alcohols, sugar phosphates, glycerophosphates, phosphate esters, disaccharides, fatty acids, and fatty acid derivatives. Succinic acid was the major small molecule present in the D. caninum ESP. Based on the literature and databases searches, we found that of 49 metabolites identified, only 12 possessed known bioactivities. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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13 pages, 1380 KiB  
Article
Momilactones A and B Are α-Amylase and α-Glucosidase Inhibitors
by Nguyen Van Quan, Hoang-Dung Tran, Tran Dang Xuan, Ateeque Ahmad, Tran Dang Dat, Tran Dang Khanh and Rolf Teschke
Molecules 2019, 24(3), 482; https://doi.org/10.3390/molecules24030482 - 29 Jan 2019
Cited by 52 | Viewed by 10339
Abstract
Momilactones A (MA) and B (MB) are the active phytoalexins and allelochemicals in rice. In this study, MA and MB were purified from rice husk of Oryza sativa cv. Koshihikari by column chromatography, and purification was confirmed by high-performance liquid chromatography, thin-layer chromatography, [...] Read more.
Momilactones A (MA) and B (MB) are the active phytoalexins and allelochemicals in rice. In this study, MA and MB were purified from rice husk of Oryza sativa cv. Koshihikari by column chromatography, and purification was confirmed by high-performance liquid chromatography, thin-layer chromatography, gas chromatography-mass spectrometry, liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and 1H and 13C nuclear magnetic resonance analyses. By in vitro assays, both MA and MB exerted potent inhibition on α-amylase and α-glucosidase activities. The inhibitory effect of MB on these two key enzymes was greater than that of MA. Both MA and MB exerted greater α-glucosidase suppression as compared to that of the commercial diabetic inhibitor acarbose. Quantities of MA and MB in rice grain were 2.07 ± 0.01 and 1.06 ± 0.01 µg/dry weight (DW), respectively. This study was the first to confirm the presence of MA and MB in refined rice grain and reported the α-amylase and α-glucosidase inhibitory activity of the two compounds. The improved protocol of LC-ESI-MS in this research was simple and effective to detect and isolate MA and MB in rice organs. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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10 pages, 1054 KiB  
Article
Effects of Postharvest Time, Heat Treatment, pH and Filtration on the Limonin Content in Newhall Navel Orange (Citrus sinensis Osbeck cv. Newhall) Juice
by Jun Zhang, Zhiqiang Yang, Yan Liang, Linyan Zhang, Wei Ling, Can Guo, Guangling Liang, Guotian Luo, Qin Ye and Balian Zhong
Molecules 2018, 23(10), 2691; https://doi.org/10.3390/molecules23102691 - 19 Oct 2018
Cited by 25 | Viewed by 4748
Abstract
Delayed bitterness causes severe economic loss in citrus juice industry worldwide, which is mostly due to the formation of limonoid compounds, especially limonin, in juice. In this study, effects of postharvest time of fruits, heat treatment, pH and filtration of juice on limonin [...] Read more.
Delayed bitterness causes severe economic loss in citrus juice industry worldwide, which is mostly due to the formation of limonoid compounds, especially limonin, in juice. In this study, effects of postharvest time of fruits, heat treatment, pH and filtration of juice on limonin content in Newhall navel orange (Citrus sinensis Osbeck cv. Newhall) juice were investigated. Our research indicated for the first time that: (1) limonin content in juice would gradually increase to a maximal level and then remained almost constant thereafter as storage time going on, whereas the maximum constant value (MCV) of limonin content in juice significantly (p < 0.05) decreased with the increment of postharvest time of fruits being juiced; (2) heat treatment and acidification of juice only speeded up the formation of limonin to the maximal level while without changing the MCV of limonin content; (3) the juice after filtration exhibited much lower MCV of limonin content compared with the unfiltered one. These experimental observations might not only provide useful information for the development of new debitterness method for navel orange juice, but also strongly support the acid-promoted delayed bitterness mechanism, suggesting the formation of delayed bitterness might primary due to the acid-promoted rather than the enzyme-catalyzed lactonization of limonoate A-ring lactone (LARL) to produce limonin in juice of navel orange. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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12 pages, 1370 KiB  
Article
Metal Chelating, Inhibitory DNA Damage, and Anti-Inflammatory Activities of Phenolics from Rambutan (Nephelium lappaceum) Peel and the Quantifications of Geraniin and Corilagin
by Yujing Li, Zhaojie Li, Hu Hou, Yongliang Zhuang and Liping Sun
Molecules 2018, 23(9), 2263; https://doi.org/10.3390/molecules23092263 - 5 Sep 2018
Cited by 40 | Viewed by 4552
Abstract
Whereas the preparation and biological properties of rambutan peel phenolics (RPP) were explored in our previous studies, the metal chelating, inhibitory DNA damage, and anti-inflammatory activities of RPP were evaluated and the important phenolics of RPP quantified in this study. Results showed that [...] Read more.
Whereas the preparation and biological properties of rambutan peel phenolics (RPP) were explored in our previous studies, the metal chelating, inhibitory DNA damage, and anti-inflammatory activities of RPP were evaluated and the important phenolics of RPP quantified in this study. Results showed that RPP had high Fe2+ and Cu2+-chelating activities with EC50 of 0.80 mg/mL and 0.13 mg/mL, respectively. RPP effectively decreased the production of hydroxyl radical with IC50 of 62.4 μg/mL. The protective effects of RPP against AAPH-induced DNA damage were also explored. RPP efficiently inhibited peroxyl radical-induced plasmid DNA strand breakage. The anti-inflammatory effects of RPP were determined using a lipopolysaccharide (LPS)-induced RAW 264.7 cell model. RPP significantly inhibited the production of nitric oxide (NO) and controlled the levels of inducible NO synthase mRNA in LPS-induced RAW 264.7 cells. The inhibitory activity increased in a dose-dependent manner. The above bioactivity of RPP was associated with its phenolic content and phenolic profiles. Furthermore, the contents of geraniin and corilagin in RPP were determined by an ultra-high performance liquid chromatography coupled with triple quadruple mass spectrometry (UPLC-QQQ-MS), showing 140.02 and 7.87 mg/g extract dry weight. Thus, RPP has potential applications as a novel nutraceutical and functional food in health promotion. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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13 pages, 576 KiB  
Article
Isolation and Purification of Potent Growth Inhibitors from Piper methysticum Root
by Truong Mai Van, Tran Dang Xuan, Truong Ngoc Minh and Nguyen Van Quan
Molecules 2018, 23(8), 1907; https://doi.org/10.3390/molecules23081907 - 31 Jul 2018
Cited by 21 | Viewed by 4886
Abstract
Piper methysticum (kava) root is known to possess promising weed suppressing activity. The present study was conducted to search for potent plant growth inhibitors from the root of this medicinal pepper plant. The ethyl acetate (EtOAc) extract exhibited the strongest reduction on growth [...] Read more.
Piper methysticum (kava) root is known to possess promising weed suppressing activity. The present study was conducted to search for potent plant growth inhibitors from the root of this medicinal pepper plant. The ethyl acetate (EtOAc) extract exhibited the strongest reduction on growth of Raphanus sativus (radish) (IC50 shoot and root growth = 172.00 and 51.31 µg/mL respectively) among solvent extracts. From this active extract, nine potent growth inhibitors involved in the inhibitory activities of P. methysticum root were isolated, purified and characterized by column chromatography (CC), gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). The six fractions purified by CC included two flavanones: 5-hydroxy-4′,7-dimethoxyflavanone (C1) and 5,7-dihydroxy-4′-methoxy-6,8-dimethylflavanone (matteucinol, C2) and six kavalactones: 5,6-dehydro-kavain (C3), a mixture of kavain and yagonin (C4), yagonin (C5) and dihydro-5,6-dehydrokavain, 7,8-dihydrokavain, dihydromethysticin and methysticin (C6). The amounts of 5-hydroxy-4′,7-dimethoxyflavanone, matteucinol, 5,6-dehydrokavain and yangonin were 0.76, 2.50, 2.75 and 2.09 mg/g dry weight (DW), respectively. The two flavanones C1 and C2 exhibited the strongest inhibition on shoot elongation (IC50 = 120.22 and 248.03 µg/mL, respectively), whilst the two kavalactone mixtures C4 and C6 showed the highest suppression on root growth of R. sativus (IC50 = 7.70 and 15.67 µg/mL, respectively). This study was the first to report the purification and inhibitory activities of the two flavanones 5-hydroxy-4′,7-dimethoxyflavanone and matteucinol in P. methysticum root. The isolated constituents from P. methysticum root including the flavanones C1 and C2 and the mixtures C4 and C6 may possess distinct modes of action on plant growth. Findings of this study highlighted that the combinations of hexane-ethyl acetate by 9:1 and 8:2 ratios successfully purified flavanones and kavalactones in P. methysticum root. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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18 pages, 849 KiB  
Article
Chemical Composition and Antibacterial Activity of Essential Oils from Ferula L. Species against Methicillin-Resistant Staphylococcus aureus
by Gulzhakhan A. Utegenova, Kyler B. Pallister, Svetlana V. Kushnarenko, Gulmira Özek, Temel Özek, Karime T. Abidkulova, Liliya N. Kirpotina, Igor A. Schepetkin, Mark T. Quinn and Jovanka M. Voyich
Molecules 2018, 23(7), 1679; https://doi.org/10.3390/molecules23071679 - 10 Jul 2018
Cited by 59 | Viewed by 5670
Abstract
Essential oils (EOs) were obtained by hydrodistillation of various parts of Ferula ovina (Boiss.) Boiss., Ferula iliensis Krasn. ex. Korovin, and Ferula akitschkensis B. Fedtsch. ex Koso-Pol., collected in the flowering/budding and fruiting stages. Eight samples of EOs isolated from F. ovina and [...] Read more.
Essential oils (EOs) were obtained by hydrodistillation of various parts of Ferula ovina (Boiss.) Boiss., Ferula iliensis Krasn. ex. Korovin, and Ferula akitschkensis B. Fedtsch. ex Koso-Pol., collected in the flowering/budding and fruiting stages. Eight samples of EOs isolated from F. ovina and four samples from F. akitsckensis were analyzed by gas chromatography–mass spectrometry (GC-MS). The major constituents of F. ovina EOs were α-pinene (6.9–47.8%), β-pinene (1.5–7.1%), sabinene (0.1–20.5%), β-phellandrene (0–6.5%), trans-verbenol (0.9–7.4%), eremophilene (3.1–12%), and 6Z-2,5,5,10-tetramethyl-undeca-2,6,9-trien-8-one (0–13.7%). The major constituents of F. akitsckensis EOs were α-pinene (0–46.2%), β-pinene (0–47.9%), sabinene (0–28.3%), eremophilene (0–10.6), β-caryophyllene (0–7.5%), himachalen-7-ol (0–28.2%), and an himachalol derivative (0–8.3%). Samples of EOs from F. ovina, F. iliensis, and F. akitsckensis were evaluated for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) pulse-field gel electrophoresis type USA300 (LAC). EOs from F. ovina exhibited the highest antibacterial activity compared to samples from other Ferula spp., with the most potent EOs being isolated from roots at the flowering and fruiting stages and stems at the fruiting stage (IC50 values of 19.1, 20.9, and 22.9 µg/mL, respectively). Although EOs demonstrated concentration-dependent inhibition of MRSA growth, analysis of the major constituents (α-pinene, β-pinene, and sabinene) showed that they had low activity, suggesting that other components were likely responsible for the observed bioactivity of the unfractionated EOs. Indeed, correlation of the GC-MS data with antibacterial activity suggested that the putative components responsible for antibacterial activity were, either individually or in combination, eremophilene and trans-verbenol. Overall, these results suggest that the EOs from F. ovina could have potential for use as alternative remedies for the treatment of infectious diseases caused by MRSA. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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Review

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25 pages, 3436 KiB  
Review
Ursolic Acid and Its Derivatives as Bioactive Agents
by Sithenkosi Mlala, Adebola Omowunmi Oyedeji, Mavuto Gondwe and Opeoluwa Oyehan Oyedeji
Molecules 2019, 24(15), 2751; https://doi.org/10.3390/molecules24152751 - 29 Jul 2019
Cited by 179 | Viewed by 11473
Abstract
Non-communicable diseases (NCDs) such as cancer, diabetes, and chronic respiratory and cardiovascular diseases continue to be threatening and deadly to human kind. Resistance to and side effects of known drugs for treatment further increase the threat, while at the same time leaving scientists [...] Read more.
Non-communicable diseases (NCDs) such as cancer, diabetes, and chronic respiratory and cardiovascular diseases continue to be threatening and deadly to human kind. Resistance to and side effects of known drugs for treatment further increase the threat, while at the same time leaving scientists to search for alternative sources from nature, especially from plants. Pentacyclic triterpenoids (PT) from medicinal plants have been identified as one class of secondary metabolites that could play a critical role in the treatment and management of several NCDs. One of such PT is ursolic acid (UA, 3 β-hydroxy-urs-12-en-28-oic acid), which possesses important biological effects, including anti-inflammatory, anticancer, antidiabetic, antioxidant and antibacterial effects, but its bioavailability and solubility limits its clinical application. Mimusops caffra, Ilex paraguarieni, and Glechoma hederacea, have been reported as major sources of UA. The chemistry of UA has been studied extensively based on the literature, with modifications mostly having been made at positions C-3 (hydroxyl), C12-C13 (double bonds) and C-28 (carboxylic acid), leading to several UA derivatives (esters, amides, oxadiazole quinolone, etc.) with enhanced potency, bioavailability and water solubility. This article comprehensively reviews the information that has become available over the last decade with respect to the sources, chemistry, biological potency and clinical trials of UA and its derivatives as potential therapeutic agents, with a focus on addressing NCDs. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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19 pages, 1914 KiB  
Review
Allelochemicals and Signaling Chemicals in Plants
by Chui-Hua Kong, Tran Dang Xuan, Tran Dang Khanh, Hoang-Dung Tran and Nguyen Thanh Trung
Molecules 2019, 24(15), 2737; https://doi.org/10.3390/molecules24152737 - 27 Jul 2019
Cited by 124 | Viewed by 11654
Abstract
Plants abound with active ingredients. Among these natural constituents, allelochemicals and signaling chemicals that are released into the environments play important roles in regulating the interactions between plants and other organisms. Allelochemicals participate in the defense of plants against microbial attack, herbivore predation, [...] Read more.
Plants abound with active ingredients. Among these natural constituents, allelochemicals and signaling chemicals that are released into the environments play important roles in regulating the interactions between plants and other organisms. Allelochemicals participate in the defense of plants against microbial attack, herbivore predation, and/or competition with other plants, most notably in allelopathy, which affects the establishment of competing plants. Allelochemicals could be leads for new pesticide discovery efforts. Signaling chemicals are involved in plant neighbor detection or pest identification, and they induce the production and release of plant defensive metabolites. Through the signaling chemicals, plants can either detect or identify competitors, herbivores, or pathogens, and respond by increasing defensive metabolites levels, providing an advantage for their own growth. The plant-organism interactions that are mediated by allelochemicals and signaling chemicals take place both aboveground and belowground. In the case of aboveground interactions, mediated air-borne chemicals are well established. Belowground interactions, particularly in the context of soil-borne chemicals driving signaling interactions, are largely unknown, due to the complexity of plant-soil interactions. The lack of effective and reliable methods of identification and clarification their mode of actions is one of the greatest challenges with soil-borne allelochemicals and signaling chemicals. Recent developments in methodological strategies aim at the quality, quantity, and spatiotemporal dynamics of soil-borne chemicals. This review outlines recent research regarding plant-derived allelochemicals and signaling chemicals, as well as their roles in agricultural pest management. The effort represents a mechanistically exhaustive view of plant-organism interactions that are mediated by allelochemicals and signaling chemicals and provides more realistic insights into potential implications and applications in sustainable agriculture. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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17 pages, 2571 KiB  
Review
Beta Glucan: Supplement or Drug? From Laboratory to Clinical Trials
by Vaclav Vetvicka, Luca Vannucci, Petr Sima and Josef Richter
Molecules 2019, 24(7), 1251; https://doi.org/10.3390/molecules24071251 - 30 Mar 2019
Cited by 124 | Viewed by 24148
Abstract
Glucans are part of a group of biologically active natural molecules and are steadily gaining strong attention not only as an important food supplement, but also as an immunostimulant and potential drug. This paper represents an up-to-date review of glucans (β-1,3-glucans) and their [...] Read more.
Glucans are part of a group of biologically active natural molecules and are steadily gaining strong attention not only as an important food supplement, but also as an immunostimulant and potential drug. This paper represents an up-to-date review of glucans (β-1,3-glucans) and their role in various immune reactions and the treatment of cancer. With more than 80 clinical trials evaluating their biological effects, the question is not if glucans will move from food supplement to widely accepted drug, but how soon. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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23 pages, 1785 KiB  
Review
Review of Ethnomedicinal, Phytochemical and Pharmacological Properties of Lannea schweinfurthii (Engl.) Engl.
by Alfred Maroyi
Molecules 2019, 24(4), 732; https://doi.org/10.3390/molecules24040732 - 18 Feb 2019
Cited by 11 | Viewed by 4466
Abstract
Lannea schweinfurthii is a valuable medicinal plant species among different ethnic groups in tropical Africa. The aim of the current study was to review existing literature on the ethnomedicinal uses, phytochemistry and pharmacological properties of L. schweinfurthii in an effort to evaluate the [...] Read more.
Lannea schweinfurthii is a valuable medicinal plant species among different ethnic groups in tropical Africa. The aim of the current study was to review existing literature on the ethnomedicinal uses, phytochemistry and pharmacological properties of L. schweinfurthii in an effort to evaluate the therapeutic potential of the species. The relevant information on the ethnomedicinal uses, phytochemistry and pharmacological properties of L. schweinfurthii was generated from several sources including books, book chapters, theses, scientific reports and journal articles obtained from the library and internet sources such as SciFinder, Wiley, Web of Science, American Chemical Society publications, PubMed, BMC, Elsevier, Science Direct, Scielo and Scopus. Traditionally, L. schweinfurthii is used against reproductive system disorders, respiratory disorders, injuries, headache, blood system disorders, infections or infestations and gastro-intestinal disorders. The phytochemical compounds that have been isolated from L. schweinfurthii include alkaloids, anthocyanins, flavonoids, glycosides, phenols, saponins, steroids, tannins and terpenoids. The in vitro and animal studies carried out so far from the crude extracts and compounds isolated from the species exhibited acetylcholinesterase inhibitory, anti-apoptotic, antibacterial, antiviral, anti-giardial, anti-inflammatory, antioxidant, antiplasmodial, antitrypanosomal, hepatoprotective, larvicidal and cytotoxicity activities. Detailed ethnopharmacological studies emphasizing clinical and toxicological evaluations are needed to assess efficacy and safety of the species as herbal medicine. Full article
(This article belongs to the Special Issue Discovery of Active Ingredients from Natural Products)
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