A new chemoenzymatic approach to the synthesis of Latanoprost and Bimatoprost

Bimatoprost (1) and Latanoprost (2) are prostaglandin analogues widely used for glaucoma treatment. We have developed a new chemoenzymatic synthesis for 1 and 2, which utilizes a highly stereoselective sequence of biotransformations catalyzed by enzymes belonging to a single microorganism (the yeast Pichia anomala). The original synthesis, starting from (-)-Corey lactone benzoate (3aR,4R,5R,6aS)-3, was modified by replacing three synthetic steps (Cdouble bond, longC reduction, stereoselective Cdouble bond, longO reduction and hydrolysis/deprotection of the benzoate ester) with a one-pot, three-enzymes reaction. The overall biotransformation gave good yields and it was highly stereoselective; noteworthy, by engineering the reaction medium, Cdouble bond, longC reduction could be modulated so that unsaturated (3aR,4R,5R,6aS,3\u2032S)-6 or saturated intermediate (3aR,4R,5R,6aS,3\u2032R)-7 could be preferentially obtained. \ua9 2014 Elsevier B.V. All rights reserved

Cloning the putative gene of vinyl phenol reductase of Dekkera bruxellensis in Saccharomyces cerevisiae

Vinylphenol reductase of Dekkera bruxellensis, the characteristic enzyme liable for \u201cBrett\u201d sensory modification of wine, has been recently recognized to belong to the short chain dehydrogenases/reductases family. Indeed, a preliminary biochemical characterisation has conferred to the purified protein a dual significance acting as superoxide dismutase and as a NADH-dependent reductase. The present study aimed for providing a certain identification of the enzyme by cloning the VPR gene in S. cerevisiae, a species not producing ethyl phenols. Transformed clones of S. cerevisiae resulted capable of expressing a biologically active form of the heterologous protein, proving its role in the conversion of 4-vinyl guaiacol to 4-ethyl guaiacol. A VPR specific protein activity of 9 \ub1 0.6 mU/mg was found in crude extracts of S. cerevisiae recombinant strain. This result was confirmed in activity trials carried out with the protein purified from transformant cells of S. cerevisiae by a his-tag purification approach; in particular, VPR-enriched fractions showed a specific activity of 1.83 \ub1 0.03 U/mg at pH 6.0. Furthermore, in agreement with literature, the purified protein behaves like a SOD, with a calculated specific activity of approximatively 3.41 U/mg. The comparative genetic analysis of the partial VPR gene sequences from 17 different D. bruxellesis strains suggested that the observed polymorphism (2.3%) and the allelic heterozygosity state of the gene do not justify the well described strain-dependent character in producing volatile phenols of this species. Actually, no correlation exists between genotype membership of the analysed strains and their capability to release off-flavours. This work adds valuable knowledge to the study of D. bruxellensis wine spoilage and prepare the ground for interesting future industrial applications