The structures of some metabolites of Penicillium diversum: α-and β-diversonolic esters

Abstract
The metabolites of Penicillium diversum include the meroterpenoids austinol (1) and isoaustin (2), together with the known poly-β-ketides lichenxanthone (3), alternariol monomethyl ether (4), and two new compounds, α- and β-diversonolic esters, (5) and (6) respectively. The structure elucidation of the latter compounds is based essentially on extensive 1H and 13C n.m.r. spectroscopic studies. The biogenetic significance of these compounds is discussed.