Peart, P.; Reynolds, W.; Williams, F.; Reese, Paul B.
Author Affiliation, Ana.
The facile bioconversion of testosterone by alginate-immobilised filamentous fungi
Journal of Molecular Catalysis B: Enzymatic
Date of Publication
The potential for biotransformation of the substrate 17ß-hydroxyandrost-4-en-3-one (testosterone) by six filamentous fungi, namely, Rhizopus oryzae ATCC 11145, Mucor plumbeus ATCC 4740, Cunninghamella echinulata var. elegans ATCC 8688a, Aspergillus niger ATCC 9142, Phanerochaete chrysosporium ATCC 24725 and Whetzelinia sclerotiorum ATCC 18687, was investigated. In this study both free cells and macerated mycelia immobilised in calcium alginate were utilised and the results (products, % yields, % transformation) were compared. In general the encapsulated cells of the microorganisms effectively generated products similar to those found using free cells. However, with immobilised macerated mycelia, isolation of the transformation products was expedited by the simple work up procedure, and their purification was facilitated by the absence of fungal secondary metabolites. Twenty seven analogues of testosterone were generated, wherein the androstane skeleton was functionalised at C-1ß, -2ß, -6ß, -7a, -11a, -14, -15a, -15ß and -16ß by the moulds. Redox chemistry was also observed. Seven of the analogues, 6ß,11a,17ß-trihydroxyandrost-4-en-3-one, 6ß,14a,17ß-trihydroxyandrost-4-en-3-one, 2,6ß-dihydroxyandrosta-1,4-diene-3,17-dione, 2ß,16ß-dihydroxyandrost-4-ene-3,17-dione, 2ß,6ß-dihydroxyandrost-4-ene-3,17-dione, 2ß,15ß,17ß-trihydroxyandrost-4-en-3-one and 2ß,3a,17ß-trihydroxyandrost-4-ene, were novel compounds. Five others, namely, 7a,17ß-dihydroxyandrost-4-en-3-one, 6ß,14a-dihydroxyandrost-4-ene-3,17-dione, 15a,17ß-dihydroxyandrost-4-en-3-one, 16ß,17a-dihydroxyandrost-4-en-3-one and 2ß,16ß,17ß-trihydroxyandrost-4-en-3-one, were fully characterised for the first time.....