Studies On The Secondary Metabolites Of Chaetomium Globosum And Chaetomium Convolutum

Background: Cytochalasans are polyketide–amino acid hybrid with a highly substituted isoindolinone and possess wide range of distinctive biological functions such as antibacterial,antineoplastic,anti-inflammatory and anti-HIV activities and phytotoxicity.Up to now,nearly 100 chae-type cytochalasan have been isolated and characterized from Chaetomium globosum.Most of C.globosum were endophytic fungus derived from plant and marine,however,few attentions has been given to animal-derived C.globosum.Objective: To isolate novel cytochalasans from C.globosum,an endophytic fungus derived from the Annelida Whitmania pigra Whitman,and Chaetomium convolutum.Methods: Rice was selected as the medium to ferment fungi in large quantity.The secondary metabolites were separated and purified from C.globosum and C.convolutum by a variety of separation methods and chromatography(Silica gel,ODS,Sephadex LH-20,MPLC,HPLC).The structure and relative configurations of single compound was determined on the basis of spectroscopic analyses(UV,IR,1D,2D NMR)and by comparison with the previous data in the literature.The absolute configuration of new compounds was established by single-crystal X-ray diffraction and ECD data.Results: Two novel cytochalasans with sixteen known compounds were isolated from C.globosum.One new isocoumarin derivative with nine known compounds were found from C.convolutum.Conclusion: Cytochalasans are found from the secondary metabolites of both C.globosum and C.convolutum.The separation of the secondary metabolites requires further investigation.