In continuation of our search for bioactive secondary metabolites from terrestrial Bacillus spp., a new microbial diketopiperazine, cis-cyclo-(His,Leu) (1) was isolated from the ethyl acetate extract of a strain B. subtilis B38, together with cis-cyclo-(Phe,Phe) (2), tryptophane (3), cis-cyclo-(Leu,Tyr) (4), cis-cyclo-(Trp,Tyr) (5) and macrolactin A (6). The chemical structures of the isolated compounds were identified by comparison of their 1D, 2D NMR and HRESIMS data with authentic spectra and literatures. To the best of our knowledge, this is the first time that cyclo-(His,Leu) has been isolated from natural products.
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http://dx.doi.org/10.1080/14786419.2012.660635 | DOI Listing |
J Antibiot (Tokyo)
January 2025
Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, Toyama, Japan.
Two new benzene-containing polyketides, cryptoic acids A (1) and B (2), along with a new acylated diketopiperazine designated cyclocryptamide (3), were isolated from the culture extract of Cryptosporangium sp. YDKA-T02. The absolute configuration of amino acid components in 3 was determined by Marfey's method.
View Article and Find Full Text PDFNat Commun
January 2025
Key Laboratory of Marine Drugs Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, P R China.
Prenylation modifications of natural products play essential roles in chemical diversity and bioactivities, but imidazole modification prenyltransferases are not well investigated. Here, we discover a dimethylallyl tryptophan synthase family prenyltransferase, AuraA, that catalyzes the rare dimethylallylation on the imidazole moiety in the biosynthesis of aurantiamine. Biochemical assays validate that AuraA could accept both cyclo-(L-Val-L-His) and cyclo-(L-Val-DH-His) as substrates, while the prenylation modes are completely different, yielding C2-regular and C5-reverse products, respectively.
View Article and Find Full Text PDFBioresour Technol
December 2024
Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai 200237, P.R. China.
Hydrothermal pretreatment (HTP) is used to increase the biochemical methane potential (BMP) of food waste (FW). The formation of melanoidins will seriously affect the microbial activity and methane production during anaerobic digestion (AD). Based on spectroscopic methods, similarities and heterogeneity of melanoidins from different sources were investigated, and the wide peak band (260-350 nm) in the ultraviolet region and the differences of amide groups of fructose-amino acid system, fructose-casein system and FW system were revealed.
View Article and Find Full Text PDFBiotechnol Rep (Amst)
March 2025
Microbiodiversity and bioprospection research group, Laboratorio de Biología Celular 19A-310, Molecular, Facultad de Ciencias, Universidad Nacional de Colombia Sede Medellín, 050034, Colombia.
The control of avocado pests and diseases heavily relies on the use of several types of pesticides, some of which are strictly monitored or not internationally accepted. New sources of bioactive molecules produced by phytopathogen-inhibiting microorganisms offer an excellent alternative for the control of pests and diseases. This study explores the potential antagonistic action against phytopathogenic microorganisms, using bacterial strains obtained from avocado thrips.
View Article and Find Full Text PDFJ Agric Food Chem
December 2024
China Pharmaceutical Culture Collection, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Tiantan Xili 1#, Beijing 100050, China.
Liupao tea is a postfermented dark tea with hypolipidemic activity. Research on the active substances in Liupao tea has primarily focused on those derived from the tea itself, overlooking the secondary metabolites produced by its predominant fungus, . In this study, CPCC 401251, the predominant strain found in Liupao tea under investigation, was isolated and analyzed.
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