Methanol adduct of puupehenone, a biologically active derivative from the marine sponge Hyrtios species

A methanal adduct of puupehenone (I), 15 alpha-methoxypuupehnol (2), an artifact resulting from the action of MeOH an puupehenone, was isolated during purification of the CH2Cl2 extract of the New Caledonian marine sponge Hyrtios sp., as the major constituent. Its chemical structure was elucidated by 2D NMR experiments. Compound 2 displayed similar antimicrobial and antifungal activity as puupehenone and a lower cytotoxic activity toward KB cells with ED50 values of 6 and 0.5 mu g/mL, respectively. Compound 2 was slightly more active against three strains of Plasmodium falciparum than puupehenone.