The preparation and bioactivities of (-)-isovelleral

The resolution of synthetic (+/-)-isovelleral (1), via chromatographic separation of the two diastereomers of the (-)-menthoxyacetic acid diester of the corresponding (+/-)-diol (3), yielded both enantiomers of the bioactive fungal metabolite (+)-isovelleral (1). While the antimicrobial and cytotoxic activities of the two enantiomers are comparable, natural (+)-1 is approximately 10 times more mutagenic towards Ames' tester strain TA98 than (-)-1. The two enantiomers of the cyclopropane ring isomer 2 also possess negligible mutagenicity compared to (+)-1. Both (+)-1 and (-)-1 have the same affinity for the vanilloid receptor, but significant different affinity for the dopamine D1 receptor. (C) 1997 Elsevier Science Ltd.