Study On The Screening For The Chemical Components Of Marine Fungi Alternaria Sp. MNP801by HPLC-UV-ELSD

High throughput screening (HTS) technology plays important role in drug lead compounds screening, but compounds screening of good bioactivity and novel structure is restricted from complex and trace nature metabolites. In this thesis, a new HPLC-UV-ELSD-Bioactivity guided screening method has been established based on the our previous bioactive metabolites guided screening from marine fungi by HPLC-UV screening method combined with antitumor (MTT method), antioxidantive (DPPH method) and trypsin inhibitory activities, This new screening method can provid HPLC-UV-ELSD spectrum of trace metabolites from marine fungus based on antioxidantive and antitumor activity guided spectrum, then bioactive metabolites can directly isolated by the preparative HPLC and this new method can avoid lost trace components of no UV absorption.Six compounds were successfully isolated from Alternaria sp. MNP801by HPLC-UV-ELSD-Bioactivity guided screening method. The structures of six compounds were identified:ergosterol peroxide (1),6,7,8-trimethoxy-coumarin (2),6,7-dimethoxy-coumarin (3),1,2-benzenedicarboxylic acid di-isobutyl ester (4), di-n-butyl-phthalate (5), bis (2-ethylexyl) phthalate (6). Compunds2-6were isolated for the first time from marine fungus Alternaria sp..The confirmatory experiment showed that compound1has strong cytotoxicity against H460,3T3, PC12and U937tumor cells, its IC50value was0.122,0.096,0.020and0.034μmol·mL-1, respectively. The acetylcholinesterase inhibitory activity of compound1,25and6were tested, the result showed that compound1,2and5do not have activity, but compound6showed significant activity, its IC50value was0.079μmol·mL Compound1showed DPPH free radical scavenging activity with its IC50value was0.259μmol·mL-1. Flow cytometry test suggested that compound1and2can inhibit the proliferation of U937cells and induce cells apoptosis for the first time.