Microbial Transformations of Hypolipemic E-Guggulsterone

Abstract

Biotransformation of E-guggulsterone (pregna-4,17(20)-cis-diene-3,16-dione) (1) by Aspergillus niger resulted in the formation of four new hydroxyl derivatives identified as 7 beta-hydroxypregna- 4,17(20)-trans-diene-3,16-dione (2), 7 beta-hydroxypregna-4,17(20)-cis-diene-3,16-dione (3), 7 beta- hydroxypregn-4-ene-3,16-dione (4), and 7 beta,15 beta-dihydroxypregn-4-ene-3,16-dione (5). The biotransformation of 1 with Cephalosporium aphidicola also resulted in the formation of four new steroidal derivatives as 11 alpha-hydroxypregna-4,17(20)-trans-diene-3,16-dione (6), 11 alpha- -hydroxypregna-4,17(20)-cis-diene-3,16-dione (7), 11 alpha,15 beta-dihydroxypregna-4,17(20)-trans-diene- 3,16-dione (8), and 11 alpha,15 beta-dihydroxypregna-4,17(20)-cis-diene-3,16-dione (9). The structures of these compounds were elucidated on the basis of 1D and 2D NMR spectroscopic techniques.

A New Lanostane Triterpene from Skimmia laureola

“…Its UV spectrum showed end absorptions only indicating the absence of any chromophoric group. The IR spectrum displayed strong absorptions at 1630 and 3300 cm −1 indicating the presence of C=C and OH groups, respectively [1,2] [20].…”

“…lycopersici (tomato) [5]. A number of coumarins, e. g. isogospherol (2) [6], heraclenol (3) [7], (+)-7-methoxy-6-(2 R-methoxy-3 -hydroxy-3 -methyl butyl)coumarin (4) [1], 5,8-dimethoxy coumarin-2H-1-benzopyran-2-one (5) [8], 7-methoxy-6-[2 -oxo-3 -methyl butyl]coumarin (6) [9] and (+)-ulopterol (7) [10,11], were isolated, in addition to various quinoline alkaloids, e. g. 4-methoxy-1-methyl-3-(2 S-acetoxy-3 -ene butyl)-2-quinolone (8) [12], 4-methoxy-1-methyl-3-(2 S-acetoxy-3 -hydroxy butyl)-2-quinolone (9) [12], 3-hydroxy-2,2,6-trimethyl-3,4,5,6-tetrahydro-2H-pyrano[3,2-c]quinoline-5-one (10) [13], 4-methoxy-1-methyl-3-(2 -oxo-3 -methyl butyl)-2-quinolone (11) [15], 4-methoxy-1-methyl-3-(2 S-hydroxy-3 -ene butyl)-2-quinolone (12) [12], methyl isoplatydesmine (13) [2], ribalinin (14) [14] and dictamnine (15) [15 -18].…”

Microbial Transformation of (+)-Adrenosterone

“…It is used as an aromatase (estrogen synthetase) inhibitor, which has potential clinical importance for managing the estrogen mediated events such as ovulation and the growth of estrogen dependant tumors [3]. In continuation of our work on microbial transformation of bioactive natural products [4], we have recently carried out transformational studies on adrenosterone (1). The fungal transformation of 1 by Cephalosporium aphidicola was therefore conducted which resulted in the formation of androsta-1,4-diene-3,11,17-trione (2), 17-hydroxyandrost-4-ene-3,11-dione (3), and 17-hydroxyandrosta-1,4-diene-3,11-dione (4).…”

Microbial Hydroxylation of Pregnenolone Derivatives

“…In continuation of our studies on the biotransformation of potential bioactive agents, [1][2][3][4][5][6][7][8][9][10][11][12] we subjected pregnenolone (1) to fungal metabolism with fungi reported to effect hydroxylation of steroids at various positions, 13,14) and as a result a series of transformed analogues 3-11 were obtained. Pregnenolone (1) is a major hormone in human nerve tissues.…”