Obtaining of 24-Norchol-4-ene-3,22-dione from Phytosterol with Mutants of Mycolicibacterium neoaurum

Abstract

Engineered mutants of Mycolicibacterium spp. are known producers of valuable steroid synthons with C₁₉ or C₂₂ skeleton. Here we describe a method for site-directed mutagenesis of Mycolicibacterium neoaurum strains, bioconversion from phytosterol, and selective purification of C₂₃ steroid 24-norchol-4-ene-3,22-dione (24-NCED) and C₂₂ steroid 20-hydroxymethylpregn-4-ene-3-one (20-HMP). The yields of crystalline products with 95% purity by the method here described are 2.74 ± 0.085 g for 24-NCED and 1.42 ± 0.085 g for 20-HMP from 10 g/L phytosterol. 20-HMP is recognized as the key precursor in chemical syntheses of pharmaceutical corticosteroids and 24-NCED is a promising synthon for the synthesis of valuable steroids and own potent biological activity.

Keywords: 20-Hydroxymethylpregn-4-en-3-one; 24-Norchol-4-ene-3,22-dione; Bioconversion; Cholesterol; Mycobacterium neoaurum; Mycolicibacterium; Phytosterol; Steroid synthon; fadA5.