[Bioconversion of C19- and C21-steroids with parent and mutant strains of Curvularia lunata].
Regio- and stereospecificity of microbial hydroxylation was studied at the transformation of 3-keto-4-ene steroids of androstane and pregnane series by the filamentous fungus of Curvularia lunata VKMF-644. The products of the transformations were isolated by column chromatography and identified using HPLC, mass-spectrometry (MS) and proton nuclear magnetic resonance (1H NMR) analyses. Androst-4-ene-3,17-dione (AD) and its 1(2)-dehydro- and 9alpha-hydroxylated (9-OH-AD) derivatives were hydroxylated by the fungus mainly in position 14alpha, while 6alpha-, 6beta- and 7alpha-hydroxylated products were revealed in minor amounts. At the transformation of C21-steroids (cortexolone and its acetylated derivatives) the presence of 17-acetyl group was shown to facilitate further selectivity of 11beta-hydroxylation. Original procedures for protoplasts obtaining, mutagenesis and mutant strain selection have been developed. A stable mutant (M4) of C. lunata with high 11beta-hydroxylase activity towards 21-acetate and 17alpha,21-diacetate of cortexolone was obtained. Yield of 11beta-hydroxylated products reached about 90% at the transformation of 17alpha, 21-diacetate of cortexolone using mutant strain M4.
Kollerov
V V
VV
Shutov
A A
AA
Fokina
V V
VV
Sukhodol'skaia
G V
GV
Gulevskaia
S A
SA
Donova
M V
MV
D000731:Androstanes / Q000378:metabolism*; D001203:Ascomycota / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D001711:Biotransformation; D003350:Cortodoxone / Q000378:metabolism*; D006900:Hydroxylation; D009154:Mutation; D011278:Pregnanes / Q000378:metabolism*
D000731:Androstanes; D011278:Pregnanes; C033936:androstane; D003350:Cortodoxone