From biosynthesis in plants to post-biosynthetic enzymatic conversion. Generation of odor-impact rose oxides from citronellol-rich essential oils

ABSTRACT

Citronellol is a monoterpene alcohol biosynthesized by various plant species belonging to different families of Angiosperm. Bioinspired by the metabolism of Rosa sp., able to produce (–)-cis-rose oxide from citronellol, we have studied and optimized a laccase-catalyzed oxidation of (±)-, (R)-, and (S)-citronellol into rose oxide diastereomers in the presence of mediators. The reaction was found to be diastereomerically cis-selective but completely non-enantioselective. The laccase-mediator system was then applied on citronellol-containing essential oils such as lemongrass (Cymbopogon citratus) and geranium (Pelargonium graveolens) essential oils in order to modify their composition beyond the plant metabolism and increase their rose oxides content, thereby tuning their olfactory properties.

KEYWORDS:

• Biocatalysis
• essential oils
• fragrance
• oxidation
• rose
• citronellol
• rose oxide

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

ML performed experiments, discussed the data and results, and co-wrote the paper.

GC discussed the data and results, and proofread the paper.

FJ performed experiments, discussed the data and results, and co-wrote the paper.

BB discussed the data and results, and proofread the paper.

SA designed the research, discussed the data and results, and wrote the paper.

Additional information

Funding

This work was supported by Université Côte d’Azur, Université de Lyon, and CNRS. ML’s PhD fellowship is co-funded by IFF-LMR and French Région SUD. We are grateful to Atsushi Tanaka (Amano Enzyme) for a loan of Amano Enzyme M120 laccase;Conseil Régional Provence-Alpes-Côte d’Azur.