Metabolites of the fungus Arthropsistruncata

The structures of 12 new polyketide metabolites produced in liquid cultures of the fungus Arthropsis truncata have been determined by a combination of chemical and spectroscopic methods. Four of these metabolites possess an unusual 2-oxaspiro[4.5]decane skeleton, and the structure assigned to one of these metabolites 20 has been confirmed by an X-ray crystallographic study of the dibenzoyl derivative 21. The absolute stereochemistry of these compounds has been predicted by application of the Harada-Nakanishi dibenzoate rule to arthropsolide D tribenzoate (32).