The microbiological hydroxylation of 4β-hydroxy-4α-methyl-5α-androstanes by Cephalosporium aphidicola

Microbiological Hydroxylations with Cephalosporium Aphidicola

“…However, neither was hydroxylated to any detectable extent on the methyl groups but were hydroxylated at C-7. 26 Similarly, 3β-hydroxy-4,4-dimethylandrost-5-en-17-one 19 was hydroxylated at C-7. 27 Both these transformations were characteristic of steroidal xenobiotic transformations by C. aphidicola and show that regiospecific biosynthetically patterned methyl group hydroxylations with this organism are probably restricted to substrates with an aphidicolane or closely related carbon skeleton.…”

Highly efficient, solvent-free esterification of testosterone promoted by a recyclable polymer-supported tosylic acid catalyst under microwave irradiation

“…Consequently, a plethora of chemical protocols have been explored to provide routes toward process improvements of an esterified variants of testosterone. Amongst the most common methods are those which employ activated carboxylic acid derivatives such as acid anhydrides or acid chlorides in the presence of basic amines such as triethylamine (Et 3 N), 40,41 pyridine (Py), [42][43][44][45][46][47][48][49] 4-(dimethylamino)pyridine (DMAP) 50 and/or N,Ndimethylaniline (DMA) 51 as well as a binary mixture of those amines (Py/DMAP), [52][53][54][55][56][57] respectively. A similar kind of conversions have been reported by Yadav et al 58 using potassium fluoride on alumina (KF-Al 2 O 3 ) as a solid base catalyst.…”

The Biotransformation of 5β-Methylestr-9-Enes by Cephalosporium Aphidicola

“…Microbiological hydroxylation is a useful transformation of steroids which provides access to sites that are often chemically relatively inaccessible. 1,2 We have been studying the microbiological hydroxylation of a range of steroids [3][4][5][6][7] using the fungus, Cephalosporium aphidicola, in order to map the factors which determine the regiochemistry of the transformation by this organism. Incubation of 5α-androstane-3,17-dione with C.aphidicola resulted 8 in hydroxylation at the C-1lα and C-14α positions.…”