Synthesis and GABA A receptor activity of 2,19-sulfamoyl analogues of allopregnanolone

Abstract

The synthesis of new analogues of allopregnanolone with a bridged sulfamidate ring over the β-face of ring A has been achieved from easily available precursors, using an intramolecular aziridination strategy. The methodology also allows the synthesis of 3α-substituted analogues such as the 3α-fluoro derivative. GABA A receptor activity of the synthetic analogues was evaluated by assaying their effect on the binding of [ 3H]flunitrazepam and [ 3H]muscimol. The 3α-hydroxy-2,19-sulfamoyl analogue and its N-benzyl derivative were more active than allopregnanolone for stimulating binding of [ 3H]flunitrazepam. For the binding of [ 3H]muscimol, both synthetic analogues and allopregnanolone stimulated binding to a similar extent, with the N-benzyl derivative exhibiting a higher EC 50. The 3α-fluoro derivative was inactive in both assays.