Zoosporicidal metabolites from an endophytic fungus Cryptosporiopsis sp. of Zanthoxylum leprieurii

Two polyketides and the natural pentacylic peptide were isolated from the culture of an endophytic fungus Cryptosporiopsis sp., which exhibited potent antifungal and zoosporicidal activities against phytopathogens. [Display omitted] ► Two polyketides and one natural pentacylic petide were isolated from the fungus Cryptosporiopsis sp. ► The isolated compounds showed potent zoosporicidal activities against the downy mildew pathogen zoospores. ► These compounds have high potentials for practical use as natural pesticides against phytopathogens. Two polyketides, cryptosporiopsin A (1) and hydroxypropan-2′,3′-diol orsellinate (3), and a natural cyclic pentapeptide (4), together with two known compounds were isolated from the culture of Cryptosporiopsis sp., an endophytic fungus from leaves and branches of Zanthoxylum leprieurii (Rutaceae). The structures of these metabolites were elucidated on the basis of their spectroscopic and spectrometric data. Cryptosporiopsin A and the other metabolites exhibited motility inhibitory and lytic activities against zoospores of the grapevine downy mildew pathogen Plasmopara viticola at 10–25μg/mL. In addition, the isolated compounds displayed potent inhibitory activity against mycelial growth of two other peronosporomycete phytopathogens, Pythium ultimum, Aphanomyces cochlioides and a basidiomycetous fungus Rhizoctonia solani. Weak cytotoxic activity on brine shrimp larvae was observed.