Study On The Secondary Metabolites Of Acremonium Phialsis Isolated From Bamboo Yellow

Shiraia bambusicola Henn.is a traditional Chinese medicinal fungi and possesses extensive pharmacological activities.The fungi isolated from S.bambusicola are those species that inhabit the fruiting body of S.bambusicola,but their relationships with S.bambusicola remained ill-defined.These fungi may produce similar metabolites to S.bambusicola due to the same living environment and become potential resource for searching natural products.In this work,the strain CA022 isolated from the stromata of S.bambusicola was selected as research materials.CA022 was determined as Acremonium cavaraeanum based on colony morphologic characteristics,microscopic morphology and the phylogenetic analysis of ITS.In preliminary biological activity assay,A.cavaraeanum CA022 showed antibacterial activity to Staphylococcus aureus and Escherichia coli.Then,A.cavaraeanum CA022 were cultured in solid-substrate fermentation cultures to prepare the organic solvent extracts.The HPLC finger-print was used to provide the basis for the abundance.There are 4 compounds that have been obtained by application of different separation techniques using various stationary and mobile phases.The structures of the 3 compounds,a novel xanthone,2,7-dihydroxy-3,6,9-trimethyl-9H-xanthene-1,4,5,8,tetraone(5 mg),along with the known ergot steroid compounds,ergosta-4,6,8(14),22-tetraen-3-one(34 mg)and ergosterol(9 mg)were elucidated by mass spectrometry,infrared spectrum,ultraviolet spectrum and nuclear magnetic resonance.The new compound has oxygen heterocyclic ring and four carbonyl groups attached to C-1,C-4,C-5,C-8.This compound is fat-soluble under acidic condition,while in an alkaline environment is water-soluble.It has very small solubility in common organic solvents and high solubility in pyridine.Currently,ergosta-4,6,8(14),22-tetraen-3-one is isolated for the first time from the solid-state fermentation of A.cavaraeanum CA022.Chemical studies of the strain A.cavaraeanum CA022 has afforded a new compound and two ergot steroid compounds.The result implied that the search for new activity development from those compounds is an effective approach.