Microbial oxidation of oleic acid

Abstract

Resting cells of Saccharomyces cerevisiae (baker's yeast, type II; Sigma) were used to convert oleic acid into 10-hydroxyoctadecanoic acid with a 45% yield. Nocardia aurantia (ATCC 12674), Nocardia sp. (NRRL 5646), and Mycobacteriumfortuitum (UI 53378) all converted oleic acid into 10-oxo-octadecanoic acid with 65, 55, and 80% yields, respectively. Structures of all metabolites were suggested by 'H and 13C nuclear magnetic resonance and by infrared and mass spectrometry. Structures of isomeric hydroxystearate and oxostearate derivatives and the stereochemical purity of hydroxystearates are difficult to prove unambiguously unless authentic standard compounds are available for spectral comparison. We describe the use of the chemical Baeyer-Villiger oxidation technique with 10-oxo-octadecanoic acid followed by mass spectral analysis of neutral extracts as a simple method to confirm the position of oxo-functional groups in the structures of fatty acid ketones. We further introduce a simple method based on 'H nuclear magnetic resonance analysis of diastereomeric S-(+)-O-acetylmandelate esters of hydroxystearates as a means of ascertaining stereochemical purities of hydroxy fatty acids.

Configurational Assignment of ‘Cryptochiral’ 10‐Hydroxystearic Acid Through an Asymmetric Catalytic Synthesis

“…A sample of biogenic 1 was obtained by fermentation of oleic acid with common bakers yeast (Saccharomyces cerevisiae; Scheme 7). [8] The product was isolated in very low yield (2%), which was sufficient for analytical purposes. It must be pointed out that we cannot ascertain whether our material was truly produced by the yeast, or if bacterial contamination may have been responsible for the observed hydration activity.…”

“…See the supporting information, Table S Analytical data agree with those reported. [57] Enzymatic Hydration of Oleic Acid [8] (R)-10-Hydroxystearic Acid (= (10R)-10-Hydroxyoctadecanoic Acid; (R)-1). Glucose (4.00 g), NaCl (1.00 g), K 2 HPO 4 (1.00 g), and (NH 4 ) 2 SO 4 (1.00 g) were dissolved in H 2 O (200 ml) and crumbled baker's yeast (Saccharomyces cerevisiae; 2.00 g) was added.…”

“…The original procedure had used soybean meal as nutrient. [8] R f = 0.65 (Et 2 O/ pentane 1:1 + 1% AcOH; Mostain). 1 H-NMR (360 MHz, CDCl 3 ): 0.88 (t, J = 6.4, 3 H); 1.28 -1.43 (m, 26 H); 1.59 -1.68 (m, 2 H); 2.34 (t, J = 7.4, 2 H); 3.55 -3.63 (m, 1 H); 6.50 (br.…”

“…[13] Many more microorganisms have since been described to mediate this reaction, including yeasts. [8] [14 -17] The activity reported for yeasts has been questioned, however, since it may have been feigned by ubiquitous bacterial contamination. [10] Analysis of the absolute configuration of 10-HSA (1)or even of its enantiomeric excessproved to be difficult because of the local symmetry in the vicinity of the chirogenic secondary alcohol unit, approaching cryptochirality.…”

Identification of (e)‐11‐hydroxy‐9‐octadecenoic acid and (E)‐9‐hydroxy‐10‐octadecenoic acid by biotransformation of oleic acid by Pseudomonas sp. 32T3

“…Bioconversion of oleic acid by a variety of microorganisms has been reported. The process may involve saturation of the alkyl chain, oxidation of the double bond to the ketoacid by Staphylococcus (2), Nocardia, Mycobacterium (3), or Sphingobacterium (4), oxidation to hydroxystearic acid by Saccharomyces (3) or Rhodococcus (5) or to several hydroxyoctadecenoic acids by Nocardia, Selenomonas, and Enterococcus (6,7) or Alcaligenes sp. (8).…”