Batch and continuous flow asymmetric synthesis of anabolic-androgenic steroids via a single-cell biocatalytic Δ¹-dehydrogenation and C17β-carbonyl reduction cascade

Abstract

Chemoenzymatic asymmetric synthesis of anabolic-androgenic steroid (+)-boldenone (3) and its prodrug (+)-boldenone undecylenate (4) was accomplished starting from commercially available 4-androstene-3,17-dione (4-AD, 1) under both batch and continuous flow conditions....

Engineered ketoreductase-catalyzed stereoselective reduction of ethyl 2′-ketopantothenate and its analogues: chemoenzymatic synthesis of d-pantothenic acid

“…It is well recognized that fine-tuning of the expression level of different components is critical for a multi-enzyme co-expression system. 21,22,33 Thus, three commercially available vectors with two cloning sites, namely pACYCDuet-1, pETDuet-1, and pRSFDuet-1, were employed, and six plasmids encoding both M3 and GDH were assembled. Notably, each gene was equipped with a T7 promoter and a ribosomal binding site (RBS) for protein overexpression.…”

Divergent Chemo‐ and Biocatalytic Route to 16β‐Methylcorticoids: Asymmetric Synthesis of Betamethasone Dipropionate, Clobetasol Propionate, and Beclomethasone Dipropionate

“…Having prepared the expected product 6 a with the correct stereochemistry, the key biocatalytic Δ 1 ‐dehydrogenation of the A ring in 6 a was examined (Table 3). Prior experience from our laboratory has demonstrated that the Δ 1 ‐dehydrogenation of Δ 4 ‐3‐ketosteroids by the flavin adenine dinucleotide (FAD)‐dependent 3‐ketosteroid‐Δ 1 ‐dehydrogenase (Δ 1 ‐KstD) from MK4, a variant of Mycobacterium smegmatis , is an efficient biocatalytic process for the highly regioselective construction of a double bond between C1 and C2 in the A ring of the steroid core during hydrocortisone synthesis [17b,c] . This motivated our attempt to achieve the Δ 1 ‐dehydrogenation of 6 a for the asymmetric synthesis of 16 β ‐methylcorticoids.…”

Merging Continuous Flow Technology, Photochemistry and Biocatalysis to Streamline Steroid Synthesis

“…A very recent chemoenzymatic approach was reported by Chen and coworkers for the synthesis of (+)-boldenone (57) and the prodrug (+)-boldenone undecylenate (58) (Scheme 19). [55] The cascade reaction involved the Δ 1 -dehydrogenation of 4-androstene-3,17-dione (4-AD, 56), catalyzed by engineered 3ketosteroid-Δ 1 -dehydrogenase (Δ1KstD) ReM2, and the subsequent regio-and stereo-selective reduction of the C17-keto group promoted by a NADH dependent 17β-carbonylreductase. Upon optimization, an effec-Scheme 17.…”