Study On Secondary Metabolites From The Fungi Myrothecium Sp. And Aspergillus Carneus

Microorganisms could survive in diverse environments such as sea, saline-alkaliland, craters, deserts, et al. Due to the differences of temperature, pH, salinity, and oxygen content, microorganisms which come from different sources process unique metabolic method and diverse biosynthetic pathway in the long-term natural selection, Thus it may produce secondary metabolites with novel structures and variety biological activities. Microoganisms has become the research hotspot of scientific research workers and discovered an important resource of lead compounds of drugs.In this study, the secondary metabolites of Myrothecium sp. and Aspergillus carneus were isolated and elucidated. Various chromatographic methods including silica gel colum chromatography, Sephadex LH-20 chromatography and HPLC were used. Their structures were elucidated by extensive spectroscopic analysis(1D and 2D NMR, MS, OR, IR), chemical methods and comparison with related known compounds. 21 compounds were isolated from the two fungus, and ZC-1, ZC-5 were new compounds. Three known compounds ZC-2, ZC-3, ZC-4 were isolated from Myrothecium sp.for the first time.Eleven compounds were obtained from the ethyl acetate extracts after solid fermentation of Myrothecium sp. which was collected from lake water of Chenghai, Yunnan Province, China. including four quinolinone alkaloids: 7-hydroxy-3-methoxyviridicatin(ZC-1), viridicatin(ZC-2), 3-methoxyviridicatin(ZC-3), viridicatol(ZC-4); five cyclic dipeptides:(11aS)-2,3-dihydro-1H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H,11aH)-dione(ZC-5), cyclopeptine(ZC-6), cyclopenin(ZC-7), dehydrocyclopeptin(ZC-8), trans-3-(3’-hydroxybenzylidene)-3,4-dihydro-4-methyl-lH-1,4-benzodiazepin-2,5-dione(ZC-9); other types: verrucosidin(ZC-10), 4-(2-hydroxybutynoxy) benzoic acid(ZC-11). Four quinolinone alkaloids and five cyclic dipeptides were evaluated antibacterial activity with microdilution method, compounds ZC-1 and ZC-2 exhibited antibacterial activity.Ten compounds were isolated from the secondary metabolites of the Aspergillus carneus which was collected from sea water from South China Sea. Their structures were elucidated as two alkaloids: cyclo-(L-tryptophyl-L-phenylalanyl)(Z-1), 3-hydroxy-4-phenylquinolin-2(1H)-one(Z-3); three polyketides: sterigmatocystin(Z-2), 3-hydroxy-5-(3-hydroxy-5-methylphenoxy) benzoic acid(Z-4), 3-hydroxy-5-(3-hydroxy-5-methylphenoxy)-4-methoxybenzoic acid(Z-5); three benzene derivatives: 4-(acetylamino) benzoic acid(Z-6), orsellinic acid(Z-7), 2,3-dihydrobenzo[b] furan-5-ol(Z-10); other types:(9E,11Z)-13-oxo-9,11-octadecadienoic acid(Z-8), 2,6,6-trimethyl-4-oxo-2-cyclohexene-1-acetic acid methyl ester(Z-9).