process for the production of optically active ª amp; dagger; and delta lactones

摘要

Optically active hydroxycarboxylic acids and lactones are prepared by microbiological reduction of ketocarboxylic acids of the general formula R.CO.(CHR1)nCOOH (wherein R represents an aliphatic non-acetylenic hydrocarbon radical of 1-14 carbon atoms, R1 represents hydrogen or a C1-5 alkyl group and n is 2 or 3), by incorporating the ketocarboxylic acid in an aqueous medium containing a viable micro-organism having a reductive capacity, allowing reduction to proceed and separating the product from the medium. The products are useful as fungistatic agents or flavouring substances. According to the Provisional Specification, R may represent an unsubstituted or substituted, saturated or unsaturated aliphatic hydrocarbon radical or a cycloaliphatic or mixed aliphatic-cycloaliphatic radical.ALSO:Micro-organisms having a reductive capacity, which have been inactivated in the course of microbiological reduction of ketocarboxylic acids, can be reconstituted by suspending them in a phosphate buffer solution of pH 6-8 containing glucose, for a few hours with aeration. Less effective reconstitution can be effected by omitting the aeration, or by simply suspending the inactivated micro-organism in a new medium for the main reaction. The micro-organisms may be yeasts (e.g. Saccharomyces cerevisiae, S. fragilis, Candida dattila, C. globiformis, C. monosa, C. pseudotropicalis or C. lactis), moulds (e.g. Penicillium notatum, Margarinomyces bubaki or Cladosporium butyri) or bacteria (e.g. Sarcina lutea or Escherichia freundi).