(+)-Menthol and Its Hydroxy Derivatives, Novel Fungal Monoterpenols from the Fusicoccin-producing Fungi, Phomopsis amygdali F6a and Niigata 2

Abstract

  In our search for new fusicoccins of unique diterpene glucosides from Phomopsis amygdali, we found that a fragrant substance was formed in the early stage of fusicoccin fermentation. This fragrant constituent was isolated and identified as (+)-menthol, which is a novel fungal metabolite as the enantiomer of well-known peppermint (−)-menthol. (+)-7-Hydroxymenthol and new (+)-(6S)-hydroxymenthol were also isolated and identified as fungal metabolites. In addition, p-menthanetriol, which has been reported as the first fungal monoterpene from the fungus, was also isolated. The possible biosynthetic relationship of these metabolites is discussed.