Microbial Conversion of α-Ionone, α-Methylionone, and α-Isomethylionone

Abstract

a-Ionone, a-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-a-ionone. 2,3-Dehydro-a-ionone, 3,4-dehydro-o-ionone, and 1-(6,6-dimethyl-2-methylene-3-cyclohexenyl)-buten-3-one were also identified. Analogous bioconversion products from a-methylionone and a-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. lonones and their derivatives are widely distributed in nature. They are important constituents of many kinds of essential oils and are presumably generated from carot-* Corresponding author.

Stereo- and Regioselective Hydroxylation of α-Ionone by Streptomyces Strains

“…When starting from racemic ␣-ionone [(6R)-(Ϫ)/(6S)-(ϩ)], one would expect to find the four diastereoisomers of the hydroxy product (Fig. 2) in equal amounts if hydroxylation was not stereoselective, as reported, e.g., for A. niger JTS 191 (18). In the chiral-phase gas chromatograms, though, only two major product peaks appear, representing the two enantiomers (3R,6R)-and (3S,6S)hydroxy-␣-ionone (Fig.…”

“…c The two values are the value from the ␤-ionone experiment before the slash and the value from the ␣-ionone experiment after the slash. hydroxy derivative, not to a product mixture as, e.g., A. niger does (18). A detailed 1 H NMR analysis (see below) shows this in fact to be 3-hydroxy-␣-ionone.…”

“…Microbial transformation of ␣-and/or ␤-ionone to a number of hydroxy and oxo derivatives has been reported for several fungal strains (2,4,8,9,18), mainly of the genus Aspergillus, but not for bacterial strains. 3-Hydroxy-␣-ionone was observed, among other metabolites, when Cunninghamella blakesleeana ATCC 8688 (2) or Aspergillus niger JTS 191 (18) was used.…”

Regio‐ and Stereoselective Hydroxylation of Optically Active α‐Ionone Enantiomers by Engineered Cytochrome P450 BM3 Mutants

“…The microbial biotransformation of racemic α‐ionone using different Streptomyces strains,19 fungi such as Aspergillus niger, 20 immobilized cells of Nicotium tabacum, 21 and cultured cells of Caragana chamlagu 22 has been reported. Moreover, different bacterial P450s from Bacillus subtillus, Sorangium cellulosum, Novaspinghobium aromaticivorans and Streptomyces have been shown to hydroxylate α‐ionone 23–27.…”

Chemical Attractant to Trap Bactrocera latifrons (Diptera: Tephritidae) in Chilli Field

“…Although, in these study the attractiveness of IN is higher than SP which opposed the previous studies these activity in the laboratory that gave moderate attractiveness that the mixture of isophorol and isophorone is higher than the mixture of -ionol and ionone. The previous study reported α-ionol and α-ionone and their derivatives could be attracted Bactrocera latifrons [5], especially 3-oxo-ionone and 3-oxo-ionol that were synthesized from microbial conversion could be attract higher than α-ionone and α-ionol [11]. Although, these attractants, α-ionone and α-ionol could be attracted fairly otherwise it response for these attractant with short time [12].…”