Abstract
The biotransformation of (−)-(4R)-isopiperitenone (1) by suspension cell culture of Mentha piperita yielded three new hydroxylated derivatives, 4−6, and two new epoxidized derivatives, 7 and 8. (−)-7-Hydroxyisopiperitenone (2) and its glucoside were previously isolated from the culture. The structures of 4−8 were elucidated using spectral methods, and their absolute stereochemistry was established by NMR experiments and correlation with compounds of known configuration.