|Keywords (Extracted from title, table of contents and abstract of thesis)
steroids, microorganisms, bioactive steroids, biotransformation, microbial transformations, bioactivities, inhibitory activities, anti-inflammatory activity
The work embodied in this dissertation comprises on three parts. Part-A describes the microbial transformations of five bioactive steroids, i.e., mesterolone (70), 17a-ethynyl-17B-hydroxy-4-androsten-3-one (81), 17a-ethyl-17B-hydroxy-4-androsten-3-one (82), cortisol (8) and (+)-androst-4-ene-3, 17-dione (4). Part-B describes the biotransformation of a seaquiterpene cedryl acetate (100). Part-C describes the bioactivities of substrates 70, 81, 82, 8, 4 and 100 and their microbial and chemical derivatives. It is further divided into two parts. Part C-1 explains the inhibitory activities of microbial and chemical derivatives of starting materials 81, 82, 8, 4 and 100 against the enzymes tyrosinase, prolyl endopoptidase and a-glucosidase while Part-C-II deals with the anti-inflammatory activity of mesterolone (70) and its derivatives.
Part_A: This part of the thesis is mainly concerned with the structural modification and characterization of steroids through microorganisms. The transformed products were either new or previously reported in the literature. They were characterized by various sophisticated spectroscopic techniques available at this institute
Mesterolone (70), on incubation with cephalosporium aphidicola, Rhizopus stolonifer and Fusarium lini, afforded six new and three known metabolites namely methyl-5a-androstan-3, 17-dione (71), 3B, 17B-dihydroxy-1a-methyl-5a-androstane (72) 1a-methyl-androst-1-ene-3, 17-dionw (73). 15a-hydroxy-1a-methydroxy-1a-methyl-5a-androst-3-one (77), 11a, 17B-dihydroxy-1a-methyl-5a-androstan-3-one (78) 15a, 17B-dihyroxy-1a-methyl-5a-androstane-3-one (79) and 15a, 17B-dihydroxy-1a-methyl-androst-1-en-3-one (80)