Biotechnological transformation of citronellene and citronellol by fungus Rhizopus oryzae (ATCC 9363) leading to interesting conversions through oxidations and rearrangements

Abstract

Abstract In this study, microbial transformation of monoterpenes (-)-citronellol, (±)-citronellene (dihydromyrcene) using Rhizopus oryzae in PDB medium was investigated. The major bioconversion product of citronellene was found to be dihydroxycitronellene, which is formed by dihydroxylation of terminal 6,7-double bond. Interestingly this molecule was reported earlier as biotransformation product of (+) citronellene by the larvae of common cutworm (Spodoptera litura) (Miyazawa et al. 2009).On thecontrary, (3S)-citronellol yielded 7-hydroxycitronellol as a major product. Severalminor products including rose oxide, rose glycol, isopulegol, artemisia-triene,1,8-nonan-diol-8-methyl, citronellyl phenyl acetate were obtained from (-)-citronellol. Whereas camphene, camphor, α-pinene, Isopulegone, terpinene-4-ol, 1,8-nonan-diol-8-methyl are the minor products obtained from (±)-citronellene. The minor products were identified by GC-MS analysis and matching fragmentationswith NIST library. Some metabolites produce possessperfumery value.