Isolation, Characterization, and Bioherbicidal Potential of the 16-Residue Peptaibols from Emericellopsis sp. XJ1056.

Eco-friendly bioherbicides are urgently needed for managing the problematic weed Amaranthus retroflexus. A mass spectrometry- and bioassay-guided screening approach was employed to identify phytotoxic secondary metabolites from fungi for the development of such bioherbicides. This effort led to the discovery of six phytotoxic 16-residue peptaibols, including five new compounds (2-6) and a known congener (1), from Emericellopsis sp. XJ1056. Their planar structures were elucidated through the analysis of tandem mass and NMR spectroscopic data. The absolute configurations of the chiral amino acids were determined by advanced Marfey's method and chiral-phase liquid chromatography-mass spectrometry (LC-MS) analysis. Bioinformatic analysis and targeted gene disruption identified the biosynthetic gene cluster for these peptaibols. Compounds 1 and 2 significantly inhibited the radicle growth of A. retroflexus seedlings, and 1 demonstrated potent postemergence herbicidal activity against A. retroflexus while exhibiting minimal toxicity to Sorghum bicolor. Structure-activity relationship analysis underscored the importance of trans-4-hydroxy-l-prolines at both the 10th and 13th positions for the herbicidal activities of these peptaibols.

Biotransformation of ursolic acid by Circinella muscae and their anti-neuroinflammatory activities of metabolites.

In this study, the biotransformation of ursolic acid by Circinella muscae CGMCC 3.2695 was investigated. Scaled-up biotransformation reactions yielded ten metabolites. Their structures were established based on extensive NMR and HR-ESI-MS data analyses, and four of them are new compounds. C. muscae could selectively catalyze hydroxylation, lactonisation, carbonylation and carboxyl reduction reactions. Furthermore, all the identified metabolites were evaluated for their anti-neuroinflammatory activities in LPS-induced BV-2 cells. Most metabolites displayed pronounced inhibitory effect on nitric oxide (NO) production. The results suggested that biotransformed derivatives of ursolic acid might be served as potential neuroinflammatory inhibitors.

Natural flavonolignans as potential therapeutic agents against common diseases.

OBJECTIVES: Plant-derived flavonolignans had been demonstrated to have various biological functions. They are an important class of natural products combined by a flavonoid unit and a phenylpropanoid unit. KEY FINDINGS: From the literature survey, 88 constituents from natural resources were identified. Different derivatives of flavonolignans were listed, fused phenylpropanoid unit with dioxane ring, or cyclic ether, or simple ether side chain, or lactone, and so on. Besides, the pharmacological effects of flavonolignans were summarized as well. It has a wide range of anti-tumour, antioxidant, anti-microorganic and anti-inflammatory effects. SUMMARY: This review had provided a full-scale profile of flavonolignans on its plant sources, phytochemistry and pharmacology, and also proposed some issues and perspectives which may be of concern in the future. It was greatly anticipated that the commercialization of the flavonolignans would lead to uplift the financial abilities of communities attending the growing of the flavonolignans and the relevant and potential production becoming an international herbal and pharmaceutical commodity.

Biotransformation of Betulonic Acid by the Fungus Rhizopus arrhizus CGMCC 3.868 and Antineuroinflammatory Activity of the Biotransformation Products.

Biotransformation of betulonic acid (1) by Rhizopus arrhizus CGMCC 3.868 resulted in the production of 16 new (3, 5, 6, and 9-21) and five known compounds. Structures of the new compounds were established by analysis of spectroscopic data. Hydroxylation, acetylation, oxygenation, glycosylation, and addition reactions involved the C-20-C-29 double bond. Antineuroinflammatory activities of the obtained compounds in NO production were tested in lipopolysaccharides-induced BV-2 cells. Compared with the substrate betulonic acid, biotransformation products 3, 8, 9, 14, and 21 exhibited an improved inhibitory effect, with IC50 values of 10.26, 11.09, 5.38, 1.55, and 4.69 µM, lower than that of the positive control, NG-monomethyl-l-arginine.

Trigonostemon species in south China: Insights on its chemical constituents towards pharmacological applications.

ETHNOPHARMACOLOGY RELEVANCE: The Euphorbiaceae family, which contains about 300 genera and more than 5000 species, is widely distributed in different regions. Trigonostemon genus comprises a wide group of tropical and temperate plants belonging to the Euphorbiaceae family. This genus includes at least 50 species throughout tropical Asia, extending from India and Sri Lanka to New Guinea. They have been employed by local populations for the treatment of asthma, poisonous snake bites, and food poisoning. AIM OF THE REVIEW: The main aim of the review is to critically analyze the reported traditional uses, bioactive chemical constituents and pharmacological activities of Trigonostemon species. MATERIALS AND METHODS: Scientific databases, including Google Scholar, PubMed, CNKI, SpringerLink, Web of Science, Wiley Online Library and SciFinder, were searched using keywords such as "Trigonostemon", "South China", "chemical constituents", or "traditional use". Thus, available articles from 2000 to 2020 were collected and analyzed. RESULTS AND DISCUSSION: This paper provides systematic data that Trigonostemon species possess a diverse phytochemical composition, (including diterpenes, alkaloids, coumarins, lignins, sesquiterpenes, triterpenoids, flavonoids, and polyphenols) found in different plant organs. Research on Trigonostemon plants has revealed critical therapeutic properties, such as antiviral, anti-tumor, antimicrobial, anti-inflammatory, and insecticidal activities. CONCLUSIONS: It is envisaged that the current review will add value to more scientific research on Trigonostemon species and enhance/promote the increased interest in the sustainable use of Trigonostemon species as well as lead to the validation of unverified ethnobotanical claims. Future studies on Trigonostemon species would focus on establishing the links between the traditional uses, active compounds and reported pharmacological activities.

Biotransformation of betulinic acid by Circinella muscae and Cunninghamella echinulata to discover anti-inflammatory derivatives.

Biotransformation of betulinic acid was carried out with Circinella muscae CGMCC 3.2695 and Cunninghamella echinulata CGMCC 3.970, yielded six previously undescribed hydroxylated metabolites and four known compounds. C. muscae could catalyze the regioselecitve hydroxylation and carbonylation at C-3, C-7, C-15 and C-21 to yield seven products. C. echinulata could catalyze the C-1, C-7 and C-26 regioselecitve hydroxylation and acetylation to yield five metabolites. The structures of the metabolites were established based on extensive NMR and HR-ESI-MS data analyses. Furthermore, most of the metabolites exhibited pronounced inhibitory activities on lipopolysaccharides-induced NO production in RAW264.7 cells.