- Clean Enzymatic Oxidation of 12α-Hydroxysteroids to 12-Oxo-Derivatives Catalyzed by Hydroxysteroid Dehydrogenase
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The C12 specific oxidation of hydroxysteroids is an essential reaction required for the preparation of pharmaceutical ingredients like ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA), which can be synthesized by Wolff-Kishner reduction of the obtained 12-oxo-hydroxysteroids. 12α-hydroxysteroid dehydrogenases (12α-HSDHs) have been shown to perform this reaction with high yields, under mild conditions and without the need of protection and deprotection steps, required in chemical synthesis. Here, the recombinant expression and biochemical characterization of the nicotinamide adenine dinucleotide (NAD+)-dependent HSDH from Eggerthella lenta (El12α-HSDH) are reported. This enzyme shows comparable properties with the well-known nicotinamide adenine dinucleotide phosphate (NADP+)-dependent enzyme from Clostridium sp. 48–50. In order to perform a viable and atom efficient enzymatic hydroxysteroid oxidation, NAD(P)H oxidase (NOX) was employed as cofactor regeneration system: NOX uses oxygen (O2) as sacrificial substrate and produces only water as side product. 10 mM of cholic acid was fully and selectively converted to 12-oxo-CDCA in 24 h. The possibility to employ this system on UCA and 7-oxo-deoxycholic acid (7-oxo-DCA) as substrates was additionally investigated. The performance of the El12α-HSDH was evaluated also in combination with a “classical” regeneration system (oxaloacetate/malate dehydrogenase) showing full conversion in 4 h. Finally, the feasibility of a catalytic aerobic-NAD+-dependent enzymatic oxidation was shown on a preparative scale (oxidation of CA to 12-oxo-CDCA) employing the El12α-HSDH-NOX system in a segmented-flow-reactor. (Figure presented.).
- Tonin, Fabio,Alvarenga, Natália,Ye, Jia Zheng,Arends, Isabel W. C. E.,Hanefeld, Ulf
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supporting information
p. 2448 - 2455
(2019/05/22)
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- Efficient Synthesis of 12-Oxochenodeoxycholic Acid Using a 12α-Hydroxysteroid Dehydrogenase from Rhodococcus ruber
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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.).
- Shi, Shou-Cheng,You, Zhi-Neng,Zhou, Ke,Chen, Qi,Pan, Jiang,Qian, Xiao-Long,Xu, Jian-He,Li, Chun-Xiu
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supporting information
p. 4661 - 4668
(2019/09/10)
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- Deoxycholic acid transformations catalyzed by selected filamentous fungi
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More than 100 filamentous fungi strains, mostly ascomycetes and zygomycetes from different phyla, were screened for the ability to convert deoxycholic acid (DCA) to valuable bile acid derivatives. Along with 11 molds which fully degraded DCA, several strains were revealed capable of producing cholic acid, ursocholic acid, 12-keto-lithocholic acid (12-keto-LCA), 3-keto-DCA, 15β-hydroxy-DCA and 15β-hydroxy-12-oxo-LCA as major products from DCA. The last metabolite was found to be a new compound. The ability to catalyze the introduction of a hydroxyl group at the 7(α/β)-positions of the DCA molecule was shown for 32 strains with the highest 7β-hydroxylase activity level for Fusarium merismoides VKM F-2310. Curvularia lunata VKM F-644 exhibited 12α-hydroxysteroid dehydrogenase activity and formed 12-keto-LCA from DCA. Acremonium rutilum VKM F-2853 and Neurospora crassa VKM F-875 produced 15β-hydroxy-DCA and 15β-hydroxy-12-oxo-LCA, respectively, as major products from DCA, as confirmed by MS and NMR analyses. For most of the positive strains, the described DCA-transforming activity was unreported to date. The presented results expand the knowledge on bile acid metabolism by filamentous fungi, and might be suitable for preparative-scale exploitation aimed at the production of marketed bile acids.
- Kollerov,Lobastova,Monti,Deshcherevskaya,Ferrandi,Fronza,Riva,Donova
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- Hydroxylation of lithocholic acid by selected actinobacteria and filamentous fungi
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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.
- Kollerov,Monti,Deshcherevskaya,Lobastova,Ferrandi,Larovere,Gulevskaya,Riva,Donova
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p. 370 - 378
(2013/03/28)
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- Preparation and characterization of some keto-bile acid azines
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New acyclic dimers of ketocholanic acids with hydrazine were obtained. Crystal structure was determined for the 3,7-dihydroxy-12-ketocholanic acid azine. Some distinctive 1H NMR signals are assigned for the entire set of azines.
- Bertolasi, Valerio,Bortolini, Olga,Fantin, Giancarlo,Fogagnolo, Marco,Perrone, Daniela
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p. 756 - 764
(2008/02/08)
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- Cyclocholates with 12-Oxo and 7,12-Oxo Groups
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Syntheses of bile acid cyclooligomers with 12- and 7,12-oxo groups (6a-d, 7a-c, 8a-b) by the Yamaguchi method are described. Cyclotrimerization is the principal reaction route for these cholic acid systems. Conversion of 7- and 12-hydroxy groups in cholic acid (la-b) to oxo groups (4a-c, 5a-c), followed by macrocyclization (6a-d, 7a-c, 8a-b) and selective reduction of the oxo groups back to hydroxy ones without cleaving the 24-carboxylic ester linkages (11) constitutes a new strategy in the synthesis of cyclocholates having unprotected hydroxy groups.
- Gao, Hongwu,Dias, Jerry Ray
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p. 719 - 724
(2007/10/03)
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- Regioselective microbial oxidation of bile acids
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High regioselectivity in the microbial oxidation of C7, C3 and C12 hydroxyl groups of cholic, chenodeoxycholic, deoxycholic and hyocholic acids 1-4 is reported. The tested microrganisms have been isolated from 50 environmental samples withdrawed from an industry that extracts and purify bile acids.
- Fantin, Giancarlo,Ferrarini, Sabina,Medici, Alessandro,Pedrini, Paola,Poli, Silvia
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p. 1937 - 1942
(2007/10/03)
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