Transformation of some 3α-substituted steroids by Aspergillus tamarii KITA reveals stereochemical restriction of steroid binding orientation in the minor hydroxylation pathway

Baeyer-Villiger Oxidation of Some C19 Steroids by Penicillium lanosocoeruleum

“…3α-Hydroxy-17a-oxa- d -homo-5α-androstan-17-one ( 5 ) was previously obtained in 53% yield by transformation of androsterone using Aspergillus tamarii KITA, but it was one of the six metabolites produced from this substrate. During that transformation, substrate as well as 3α-hydroxy-17a-oxa- d -homo-5α-androstan-17-one also underwent hydroxylation, giving a mixture of 1β- and 11β-hydroxy products [16]. Epiandrosterone was converted to 3β-hydroxy-17a-oxa- d -homo-5α-androstan-17-one ( 6 ) with 10% yield by Aspergillus terreus [18].…”

“…The use of the chimeric enzyme PASTMO (a hybrid of phenylacetone monooxygenase (PAMO) and bacterial steroid monooxygenase (STMO) from Rhodococcus rhodochrous ) in the biotransformation of progesterone afforded the final lactone (testololactone) with a moderate (19%) conversion [4]. Among microorganisms, fungal species of the Penicillium [5,6,7,8,9,10], Aspergillus [11,12,13,14,15,16,17,18,19,20] and Fusarium genera [21,22,23] are especially known to transform 4-en-3-oxo and 3β-hydroxy-5-ene C 21 as well as C 19 steroids. Enzymes performing oxidation belong to the family of NADPH-dependent steroid Baeyer-Villiger monooxygenases (BVMOs) containing FAD as a cofactor.…”

“…P. camemberti was able to carry out the oxidation of pregnenolone and DHEA to testololactone, which could be formed via two routes: through 4-en-3-ketone or 3β-hydroxylactone [9]. In most cases of transformations described in literature, the steroids, besides the Baeyer-Villiger oxidation, also underwent hydroxylation, reduction or dehydrogenation [8,12,15,16,19,23,29]. The mixtures of metabolites formed during the transformations led to difficulties in product purification.…”

Microorganisms as Biocatalysts and Enzyme Sources

“…The ability of Biotransformation products of (20S)-20-hydroxymethylpregna-1, 4-dien-3-one (112). microorganisms to reduce 17-keto-to 17β-hydroxysteroids was evidenced for a wide variety of substrates and microorganisms of different taxonomy: bacteria, fungi, and yeast [54,56,57,66]. The ability of different microorganism to transform progesterone (102).…”