Novel antimycotic epicoccolides, sordariones and further new zoosporicidal natural products from endophytic fungi inhabiting Cameroonian medicinal plants

The work was targeted to investigate and identify plant protecting natural products from sixteen endophytes isolated from five Cameroonian medicinal plants (Zanthoxylum lemairei, Zanthoxylum leprieurii, Endodesmia calophylloides, Enanthia chlorantha, and Teobroma cacao). Mass growth of each fungus for production of interesting compounds was carried out in two different fermentation conditions. Chemical and biological investigation of the obtained active extracts afforded 133 natural products, from which 36 were new compound and 7 featured new skeletons. The isolated pure compounds exhibited motility inhibitory and lytic activities against zoospores of the grapevine downy mildew pathogen Plasmopara viticola and inhibitory activity against mycelial growth of two other peronosporomycete phytopathogens, Pythium ultimum, Aphanomyces cochlioides and a basidiomycetous fungus Rhizoctonia solani. Cytotoxicity and antimicrobial activities of some isolated pure compounds were also noticed. These compounds might serve as defensive weapon for the fungus and its host plant. In view of structural diversity and different biological activities exhibited by the isolated compounds, it is right to say that the study of endophytes from tropical plants as sources of new chemicals and drug candidates is promising.