title: 7alpha- and 12alpha-Hydroxysteroid dehydrogenases from Acinetobacter calcoaceticus lwoffii: a new integrated chemo-enzymatic route to ursodeoxycholic acid.
abstract: We report the very efficient biotransformation of cholic acid to 7-keto- and 7,12-diketocholic acids with Acinetobacter calcoaceticus lwoffii. The enzymes responsible of the biotransformation (i.e. 7alpha- and 12alpha-hydroxysteroid dehydrogenases) are partially purified and employed in a new chemo-enzymatic synthesis of ursodeoxycholic acid starting from cholic acid. The first step is the 12alpha-HSDH-mediated total oxidation of sodium cholate followed by the Wolf-Kishner reduction of the carbonyl group to chenodeoxycholic acid. This acid is then quantitatively oxidized with 7alpha-HSDH to 7-ketochenodeoxycholic acid, that was chemically reduced to ursodeoxycholic acid (70% overall yield).
authors.affiliation: Dipartimento di Biologia ed Evoluzione, Università di Ferrara, C.so Ercole I d'Este 32, I-44100 Ferrara, Italy.
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Giovannini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Grandini
authors.forename: Daniela
authors.initials: D
authors.lastname: Perrone
authors.forename: Paola
authors.initials: P
authors.lastname: Pedrini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Fantin
authors.forename: Marco
authors.initials: M
authors.lastname: Fogagnolo
mesh_terms: D016954:Acinetobacter calcoaceticus / Q000201:enzymology*; D001711:Biotransformation; D002384:Catalysis; D002478:Cells, Cultured; D002793:Cholic Acids / Q000378:metabolism; D006913:Hydroxysteroid Dehydrogenases / Q000302:isolation & purification / Q000378:metabolism*; D014580:Ursodeoxycholic Acid / Q000378:metabolism*
chemical_list: D002793:Cholic Acids; D014580:Ursodeoxycholic Acid; D006913:Hydroxysteroid Dehydrogenases; C025376:7 alpha-hydroxysteroid dehydrogenase; C019189:12 alpha-hydroxysteroid dehydrogenase