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

Abstract

The synthesis of new analogues of allopregnanolone with a bridged sulfamidate ring over the a−face of ring A has been achieved from easily available precursors, using an intramolecular aziridination strategy. The methodology also allows the synthesis of 3a-substituted analogues such as the 3a-fluoro derivative. GABAA receptor activity of the synthetic analogues was evaluated by assaying their effect on the binding of [3H]flunitrazepam and [3H]muscimol. The 3a-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 EC50. The 3á-fluoro derivative was inactive in both assays.