Assessment of headspace solid-phase microextraction (HS-SPME) for control of asymmetric bioreduction of ketones by Alternaria alternata

Abstract

The aim of this study was to assess the effectiveness of headspace solid-phase microextraction (HS-SPME) compared to liquid–liquid extractions using with methylene chloride (CH₂Cl₂) for control of fungal biotransformation of ketones of varying volatility. The proposed method was successfully applied. The best way to extract all the components of the mixture (alcohols, aldehydes) in quantities similar to the extraction of methylene chloride was the use of fibres coated with a combination of nonpolar material. SPME fibre assembly polydimethylsiloxane/divinylbenzene (PDMS/DVB) was most suitable for the extraction of the products mixture obtained after biotransformation of acetylcyclohexane and acetophenone. On the other hand, the best results were obtained for 2-acetylthiophene, α,α,α-trifluoroacetophenone and their derivatives using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibre. In addition, our study showed that Alternaria alternata is a good biocatalyst for bioreduction of ketones to alcohols according to Prelog's rule.

Keywords:

• HS-SPME
• liquid–liquid extractions
• fungal biotransformation
• ketones
• Alternaria alternate

Acknowledgements

We thank prof. Tadeusz Kowalski (Department of Forest Pathology, Mycology and Tree Physiology, University of Agriculture in Krakow) for his help in the study.

Disclosure statement

No potential conflict of interest was reported by the authors.