New antitumour fungal metabolites from Alternaria porri.

Chemical investigation of the onion pathogenic fungus Alternaria porri resulted in the isolation of two new phthalides named zinnimide (2) and deprenylzinnimide (8), along with a new bianthraquinone, alterporriol F (10). The structures of the new metabolites were characterised by spectroscopic analysis and chemical degradation. Of the new compounds isolated, alterporriol F was highly cytotoxic towards HeLa and KB cells, with IC(50) values of 6.5 and 7.0 microg mL(-1).