Secondary Metabolites And Biological Activity Of Chaetomium Sp.

Fungi are rich resources of a variety of structurally diverse secondary metabolites.They have the advantage of being easy to obtain from the environment and easy to expand.Lots of natural products that have improved our lives are from fungus secondary metabolites,such as penicillin,cephalosporins,griseofulvin and lovastatin.In recent years,a lot of novel and bioactive natural products associated with diverse structural types of chaetoglobosins,azaphilones,anthraquinone,steroids and terpenoids have been discovered.Many of the compounds have significant biological activities,such as antitumor,cytotoxic,anti-inflammatory,antibiotic,enzyme inhibitory and so on.Through the screening of five strains of Chaetomium sp.and three kinds of medium,It was found that the metabolites of C518 and C521 were abundant in PD medium.The metabolites and their biological activities were studied.After extraction,silica gel column chromatography,gel column chromatography and HPLC analysis of the mycelium and filtrate,14 compounds were isolated and purified.the structures of those compounds are identified respectively to be ergosterol?1?,?-?-Aureonitol?2?,5-Hydroxymethylfurfura?3?,ergosterol peroxide?4?,Epicoccone B?5?,3-methoxyepicoccone B?6?,flavipin?7?,mollipilin A?8?,chaetoglobosin B?9?,chaetolactone?10?,cyclo-?S-Pro-R-Leu??11?,tyrosol?12?,chaetoglocin A?13?and epicoccone?14?by spectroscopic methods(MS,¹H,¹³C NMR and2D NMR).Among them,compound 10 is a polyketide with a new carbon skeleton,11 is first isolated from the fungus Chaetomium sp.The antioxidant activity of 1-7 was determined by literature assay.Compounds 5-7 had marked activity(IC₅₀=10.8,23.2 and 7.2?M,respectively).In addition,alpha glucosidase inhibitory activity of 5-7 was measured,and 6was inactive,compounds 5 and 7 were active(IC₅₀=27.3 and 33.8?M,respectively).14 secondary metabolites were obtained from two Chaetomium sp.,including a new compound chaetolactone?10?with a new carbon skeleton.Compounds 5-7 displayed marked antioxidant activity and alpha glucosidase inhibitory activity.This work may provide a theoretical basis for developing these fungi.