81873-91-8Relevant articles and documents
Efficient Synthesis of 12-Oxochenodeoxycholic Acid Using a 12α-Hydroxysteroid Dehydrogenase from Rhodococcus ruber
Shi, Shou-Cheng,You, Zhi-Neng,Zhou, Ke,Chen, Qi,Pan, Jiang,Qian, Xiao-Long,Xu, Jian-He,Li, Chun-Xiu
, p. 4661 - 4668 (2019/09/10)
12α-Hydroxysteroid dehydrogenase (12α-HSDH) has the potential to convert cheap and readily available cholic acid (CA) to 12-oxochenodeoxycholic acid (12-oxo-CDCA), a key precursor for chemoenzymatic synthesis of the therapeutic bile acid ursodeoxycholic acid (UDCA). In this work, a native nicotinamide adenine dinucleotide (NAD+)-dependent 12α-hydroxysteroid dehydrogenase (Rr12α-HSDH) from Rhodococcus ruber was identified using a structure-guided genome mining (SSGM) approach, which is based on the structure of cofactor pocket and the conserved nicotinamide cofactor binding motif alignment. Rr12α-HSDH was heterologously overexpressed in Escherichia coli BL21 (DE3), purified and characterized. The purified Rr12α-HSDH showed a high oxidative activity of 290 U mg?1protein toward CA, with a catalytic efficiency (kcat/KM) of 5.10×103 mM?1 s?1. In a preparative biotransformation (100 mL), CA (200 mM, 80 g L?1) was efficiently converted to 12-oxo-CDCA in 1 h, with a 85% isolated yield and a space-time yield (STY) of up to 1632 g L?1 d?1. Furthermore, Rr12α-HSDH was shown to be able to catalyze the oxidation of other 12α-hydroxysteroids at high substrate loads (up to 200 mM), giving the corresponding 12-oxo-hydroxysteroids in 71%–85% yields, indicating the great potential of Rr12α-HSDH as a promising biocatalyst for the synthesis of various therapeutic bile acids. (Figure presented.).
Regioselective oxidation of cholic acid and its 7β epimer by using o-iodoxybenzoic acid
Dangate, Prasad S.,Salunke, Chetan L.,Akamanchi, Krishnacharya G.
, p. 1397 - 1399 (2011/11/06)
Rational exploration directed by DFT (density functional theory) based atomic Fukui indices, lead to development of regioselective oxidation of cholic acid and its 7β epimer by o-iodoxybenzoic acid. In case of cholic acid only, 7α-hydroxyl underwent oxidation, where as in its 7β epimer the selectivity was towards 12α-hydroxy group. Since these oxidations are the key steps in synthesis of ursodeoxycholic acid starting from cholic acid these findings may be useful in devising a protection free synthetic route.