Secondary Mould Metabolites. Part 16. Stemphyltoxins, New Reduced Perylenequinone Metabolites from Stemphylium botryosum var. Lactucum.

The structures of five new metabolites, stemphyltoxins (I)-(IV) [(Ia)-(Ic), (II)] and stemphyperylenol (III), are elucidated by analysis of their 1H and 13C NMR spectra [the relative configuration of (II) is unknown].