On the mode of conversion of racemic C14-C19 .gamma.-hydroxy alkene fatty acids into C7-C11, optically active .gamma. and .delta.-lactones in Cladosporium suaveolens

Biosynthesis of Dodecano‐4‐lactone in Ripening Fruits: Crucial Role of an Epoxide‐Hydrolase in Enantioselective Generation of Aroma Components of the Nectarine (Prunus persica var. nucipersica) and the Strawberry (Fragaria ananassa)

“…The introduction of 0-atoms is generally achieved by i) hydratization of double bonds (e.g. linoleic acid + ricinoleic acid), ii) direct functionalization of nonactivated CH, groups by mixed-function oxygenases, and iii) introduction of a hydroperoxide into a pentadienyl segment of linoleic-and linolenic acid by a lipoxygenase [6] [7]. Recently, we have shown that dodecano-Clactone (4), at least, is produced by a different route.…”

Enantiodifferentiation of four ?-lactones produced byPenicillium Roqueforti

“…According to several authors, the presence of the two enantiomers of each lactone suggested that the precursors of the lactones were present as both enantiomers, that inversion of configuration occurred during metabolisation, or that substrate degradation followed different pathways. [12][13][14][15]21 According to Fuganti et al 13 the biogeneration of lactones proceeds in quite different ways for several microorganisms such as Yarrowia lipolytica, Pichia ohmeri, Fusarium poae, and Cladosporium suaveolens. An enantiomeric excess in favour of the (6Z)-(S)-dodecen-4-olide is obtained during the degradation of C18 hydroxyacids by Pichia ohmeri, whereas the reverse is observed when Yarrowia lipolytica is used.…”

“…14 An enantiomeric excess of 22% for the (R) isomer of 4-hexanolide obtained by bioconversion of 12-hydroxy-(9Z)-hexadecenoic acid by Cladosporium suaveolens is given by Cardiollo et al 21 The (S) enantiomer is present in large excess in the culture of Fusarium poae in a liquid malt broth. 12 Oleic and linoleic acids, the most important fatty acids of soy bean oil, may be considered the precursors of 4-dodecanolide and (6Z)-dodecen-4-olide.…”

“…It was proven that the precursors of lactones were hydroxylated fatty acids of C18 chain length, which were shortened by ␤-oxidation steps followed by lactonization. 8,15,21 Haffner and Tressel 15 have studied the biotransformation of oleic acid to ␥ C10, C12 saturated and unsaturated lactones in Sporobolomyces odorus. They concluded that at least three different metabolic pathways were used for the first step including action of 10-hydratase and/or 10 lipoxygenase for C12 lactone formation.…”