Configurational analysis and relative binding affinities of 16-methyl-5α-androstane derivatives
作者:Pál Tapolcsányi、János Wölfling、István Tóth、Mihály Szécsi、Péter Forgó、Gyula Schneider
DOI:10.1016/s0039-128x(01)00113-1
日期:2001.11
The four possible isomers 16 beta -hydroxymethyl-5 alpha -androstane-3 beta ,17 beta -dioI 1, 16 alpha -hydroxymethyl-5 alpha -androstane-3 beta ,17 beta -diol 2, 16 beta -hydroxymethyl-5 alpha -androstane-3 beta ,17 alpha -diol 3 and 16 alpha -hydroxymethyl-5 alpha -androstane-3 beta ,17 alpha -diol 4 with proven configuration were converted into the corresponding 16 beta -methyl-5 alpha -androstane-3 beta ,17 beta -dioI 5, 16 alpha -methyl-5 alpha -androstane-3 beta ,17 beta -diol 6, 16 beta -methyl-5 alpha -androstane-3 beta ,17 alpha -diol 7, 16 alpha -methyl-5 alpha -androstane-3 beta ,17 alpha -diol 8, furthermore into the 16 beta -methyl-17 beta -hydroxy-5 alpha -androstane-3-one 13, 16 alpha -methyl-17 beta -hydroxy-5 alpha -androstan-3-one 14, 16 beta -methyl-17 alpha -hydroxy-5 alpha -androstan-3-one 15 and 16 alpha -methyl-17 alpha -hydroxy-5 alpha -androstan-3-one 16. The steric structures of the resulting epimers were determined by means of H-1-, and C-13-NMR spectroscopy. In this way, comparison was possible with the C-16 epimers 5, 6 and 13, 14 prepared earlier by a different route, and the series of isomers could be completed with the steric structures of 16 beta -methyl-17 alpha -hydroxy-5 alpha -androstan-3 beta -ol 7 and 16 alpha -methyl-17 alpha -hydroxy-5 alpha 8 and with their 3-keto derivatives 15 and 16. The relative binding affinities of the 16-methyl-5 alpha -androstane-3 beta ,17-diols 5, 6, 7, 8 and 17-hydroxy-16-methyl-5 alpha -androstan-3-ones 13, 14, 15, 16 were studied. The introduction of a 16-methyl substituent into 5 alpha -androstane molecules substantially decreases the binding affinity to the androgen receptor and 16 alpha -methyl derivatives were always bound more weakly than the 16 beta -methyl isomers. (C) 2001 Elsevier Science Inc. All rights reserved.