Biotransformation of gamma-terpinene and (-)-alpha-phellandrene by the larvae of common cutworm (Spodoptera litura).

gamma-Terpinene was mixed in artificial diet at a concentration of 1 mg/g of diet, and the diet was fed to the last instar larvae of common cutworm (Spodoptera litura). Metabolites were recovered from frass and analyzed spectroscopically. gamma-Terpinene was transformed mainly to p-mentha-1,4-dien-7-oic acid and p-cymen-7-oic acid (cumic acid). Similarly, (-)-alpha-phellandrene was transformed mainly to (4R)-p-mentha-1,5-dien-7-oic acid and p-cymen-7-oic acid (cumic acid). The C-7 position (allylic methyl group) of gamma-terpinene and (-)-alpha-phellandrene was preferentially oxidized.