Humicolone, a new phenolic tetralone in acetal form, was isolated, together with a known phenolic tetralone, from cultures of Humicola grisea Traaen, a hyphomycete taken from drifting wood in the southeastern lagoon of New Caledonia. Humicolone, determined from MTPA esters to have absolute configuration 1'R,3S,4S, showed cytotoxicity on KB cell lines, with IC 5 0 values between 1 and 5ppm. Another unidentified filamentous fungus, also from drifting wood in a nearby New Caledonian marine area, gave phosphatidyl cholines and, unusually for fungi, a bisabolane sesquiterpene.