77060-26-5Relevant articles and documents
Hydroxylation of lithocholic acid by selected actinobacteria and filamentous fungi
Kollerov,Monti,Deshcherevskaya,Lobastova,Ferrandi,Larovere,Gulevskaya,Riva,Donova
, p. 370 - 378 (2013/03/28)
Selected actinobacteria and filamentous fungi of different taxonomy were screened for the ability to carry out regio- and stereospecific hydroxylation of lithocholic acid (LCA) at position 7β. The production of ursodeoxycholic acid (UDCA) was for the first time shown for the fungal strains of Bipolaris, Gibberella, Cunninghamella and Curvularia, as well as for isolated actinobacterial strains of Pseudonocardia, Saccharothrix, Amycolatopsis, Lentzea, Saccharopolyspora and Nocardia genera. Along with UDCA, chenodeoxycholic (CDCA), deoxycholic (DCA), cholic (CA), 7-ketodeoxycholic and 3-ketodeoxycholic acids were detected amongst the metabolites by some strains. A strain of Gibberella zeae VKM F-2600 expressed high level of 7β-hydroxylating activity towards LCA. Under optimized conditions, the yield of UDCA reached 90% at 1 g/L of LCA and up to 60% at a 8-fold increased substrate loading. The accumulation of the major by-product, 3-keto UDCA, was limited by using selected biotransformation media.
Improved enantioselectivity in the epoxidation of cinnamic acid derivatives with dioxiranes from keto bile acids
Bortolini, Olga,Fantin, Giancarlo,Fogagnolo, Marco,Forlani, Roberto,Maietti, Silvia,Pedrini, Paola
, p. 5802 - 5806 (2007/10/03)
The asymmetric epoxidation of substituted cinnamic acids has been obtained in the presence of different keto bile acid derivatives as optically active carbonyl inducers and Oxone as oxygen source. Predominant or almost exclusive formation of both enantiomeric epoxides is obtained (ee up to 95%) depending on the specific substitution at carbons C(7) and C(12) of the bile acid.
Regiospecific oxidoreductions catalyzed by a new Pseudomonas paucimobilis hydroxysteroid dehydrogenase
Bianchini, Ercolina,Chinaglia, Nicola,Dean, Mariangela,Giovannini, Pier Paolo,Medici, Alessandro,Pedrini, Paola,Poli, Silvia
, p. 1391 - 1398 (2007/10/03)
The preparative-scale regio- and stereo-specific oxidation of hydroxy groups and reduction of keto functions at C(3) of several C21 bile acids, catalyzed by a new 3α-hydroxysteroid dehydrogenase (3α-HSDH) is reported. The crude enzyme, isolated from the cells of Pseudomonas paucimobilis, revealed the presence of a further enzymatic fraction containing a secondary alcohol dehydrogenase (SADH), that has been used to recycle the cofactor.
Enzymatic α/β Inversion of C-3 Hydroxyl of Bile Acids and Study of the Effects of Organic Solvents on Reaction Rates
Riva, Sergio,Bovara, Roberto,Zetta, Lucia,Pasta, Piero,Ottolina, Gianluca,Carrera, Giacomo
, p. 88 - 92 (2007/10/02)
Enzymatic α/β inversion of the C-3 hydroxyl of numerous bile acids containing different numbers of hydroxyl groups in the skeleton and side chains of different lengths has been carried out.Inversion was obtained in two steps through the sequential use of the commercial enzymes 3α- and 3β-hydroxysteroid dehydrogenase, employed in the free form or immobilized on Eupergit C.The transformations were practically quantitative and the products more than 98percent pure.NAD was regenerated in situ with the pyruvate/lactic dehydrogenase system and NADH with the formate/formate dehydrogenase system.The effects of product inhibition on reaction rates and the favorable effects produced by low concentrations (7-10percent, v/v) of ethyl acetate and ethanol were also examined.
