Preparative-scale regio- and stereospecific oxidoreduction of cholic acid and dehydrocholic acid catalyzed by hydroxysteroid dehydrogenases

Abstract

NAD(P)-dependent hydroxysteroid dehydrogenases were used as catalysts for the oxidoreduction of the hydroxyl-keto groups of cholic acid (3cu,7a,l2a-trihydroxy-5~-cholan-24-oic acid) and dehydrocholic acid (3,7,12-trioxo-5~-cholan-24-oic acid). Cholic acid was regiospecifically oxidized, on a preparative scale, at each of the three possible positions, and dehydrocholic acid regio-and stereospecifically reduced at each of the three positions. The compounds were quantitatively transformed and the producta were 97-99% pure. The assignment of product structure was made by NMR. The nicotinamide cofactors were enzymatically regenerated, in situ, with the a-ketoglutarate/glutamate dehydrogenase, formate/formate dehydrogenase or glucose/glucose dehydrogenase systems. The enzymes were employed in the free form or immobilized on Sepharose CL-4B.

A new enzymatic route to the synthesis of 12-ketoursodeoxycholic acid

“…The organic layer was dried over sodium sulfate and evaporated to dryness. The product, crystallized from ethyl acetate, showed physical properties coincident with those reported in literature (Riva et al, 1986).…”

Exploitation of the alcohol dehydrogenase‐acetone NADP‐regeneration system for the enzymatic preparative‐scale production of 12‐ketochenodeoxycholic acid

“…(2) is an important intermediate in the synthesis of ursodeoxycholic acid, a drug used in cholesterol gall-stones dissolution therapy and in the treatment of the autoimmune hepatopathy, known as primary sclerosis cholangitis (PSC) (Beuers, 2005;Festi et al, 1990). The quantitative regioselective oxidation of the 12a-hydroxyl group of cholic acid (1) by action of a NADP-dependent 12a-hydroxysteroid dehydrogenase coupled with an efficient recycling system (a-ketoglutarate/glutamate dehydrogenase) has been previously described (Carrea et al, 1984(Carrea et al, , 1985Riva et al, 1986). However, this system resulted not to be applicable on an industrial scale due to the relative high cost of a-ketoglutarate for this specific application.…”

One‐Pot Multienzymatic Synthesis of 12‐Ketoursodeoxycholic Acid: Subtle Cofactor Specificities Rule the Reaction Equilibria of Five Biocatalysts Working in a Row

“…[4][5][6][7] Several years ago, we reported the HSDH-catalyzed two-steps enzymatic synthesis of 12-ketoursodeoxycholic acid (3a,7b-dihydroxy-12-oxo-5b-cholanoic acid, Scheme 1, 3), a key intermediate for the synthesis of ursodeoxycholic acid (3a,7b-dihydroxy5b-cholanoic acid) by a Wolff-Kishner reduction.…”