Microbial conversion of α-ionone, α-methylionone, and α-isomethylionone

Abstract

α-Ionone, α-methylionone, and a-isomethylionone were converted by Aspergillus niger JTS 191. The individual bioconversion products from a-ionone were isolated and identified by spectrometry and organic synthesis. The major products were cis-3-hydroxy-a-ionone, trans-3-hydroxy-a-ionone, and 3-oxo-α-ionone. 2,3-Dehydro-α-ionone, 3,4-dehydro-β-ionone, and 1-(6,6-dimethyl-2-methylene-3-cyclohexenyl)-buten-3-one were also identified. Analogous bioconversion products from α-methylionone and α-isomethylionone were also identified. From results of gas-liquid chromatographic analysis during the fermentation, we propose a metabolic pathway for a-ionones and elucidation of stereochemical features of the bioconversion. © 1988, American Society for Microbiology.