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Screening of fungal and bacterial strains allowed selection of two Streptomyces strains ( S. platensis and S. cinnamonensis) that oxidatively cleave, in moderate to high yields (up to 65% in 24 h), the quinonic ring of a thiazole fused 1,4-naphthoquinone compound, INO5042, used as a model compound for a series of homologous substituted heterocyclic naphthoquinones. The respective products of these whole-cell biotransformations were identified as isomeric phenol-carboxylic acids resulting from a C-C bond cleavage at a position vicinal to each one of the carbonyl groups. The culture and incubation conditions have been optimised and the mechanism of this biotransformation investigated using oxygen isotope incorporation. The results of 18O2 incorporation indicate a dioxygenase reaction, the mechanism of which is discussed in relation with that of hydroquinone-epoxidases, a family of oxygenating enzymes involved in the biosynthesis of polyketide antibiotics in Streptomyces.

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We have investigated the preparation of (R)‐ and (S)‐1‐phenyl‐1‐(2‐phenylthiazol‐5‐yl)‐methanol by asymmetric bioreduction of the corresponding bulky ketone 1‐phenyl‐1‐(2‐phenylthiazol‐5‐yl)‐methanone with whole microbial cells. A short screening of 38 microbial strains allowed the selection of two suitable yeast strains fulfilling enantiocomplementarity. Gram‐scale preparations of the S‐ and R‐alcohols were achieved with high yield and high optical purity using, respectively, Saccharomyces montanus CBS 6772 (yield 79%, ee 96%) and Rhodotorula glutinis var. dairenensis MUCL 30607 (yield 96%, ee 91%). The two enantiomeric alcohols prepared are novel compounds described here for the first time.