Biotransformation of (+)-(1R)- and (−)-(1S)-fenchone by the larvae of common cutworm (Spodoptera litura)

Biotransformation of (+)-(1R)- and (−)-(1S)-fenchone in Spodoptera litura larvae has been investigated. (+)- and (−)-Fenchone were regio- and stereo-selective hydroxylated. (+)-Fenchone was transformed to one new terpenoid, (+)-(1S,4R)-3-oxo-2,2,4-trimethyl-cyclopentylacetic acid and four known terpenoids, (+)-(1S,6S)-6-exo-hydroxyfenchone, (+)-(1S,6R)-6-endo-hydroxyfenchone, (+)-(1R)-10-hydroxyfenchone and (+)-(1S,5R)-5-exo-hydroxyfenchone. (−)-Fenchone was transformed to one new terpenoid, (−)-(1S)-10-hydroxyfenchone and four known terpenoids, (−)-(1R,6R)-6-exo-hydroxyfenchone, (−)-(1R,6S)-6-endo-hydroxyfenchone, (−)-(1R,5S)-5-exo-hydroxyfenchone and (−)-(1R,4S)-3-oxo-2,2,4-trimethyl-cyclopentylacetic acid. C-6 position of (+)- and (−)-fenchone was progressing to the carboxylic acid, which is characteristically metabolic pathway compared with any other biocatalysts. Intestinal bacteria from the frass of larvae did not participate in the metabolism of (+)- and (−)-fenchone.