A computational study on conformational geometries, chemical reactivity and inhibitor property of an alkaloid bicuculline with γ-aminobutyric acid (GABA) by DFT

► The equilibrium bicuculline conformers have been obtained by geometry optimizations using DFT. ► The antagonistic behavior of bicuculline with GABA receptor have been evaluated using 6-311G(d,p) basis. ► The specific site of interaction of BIC with GABA receptor have been calculated. ► The global and local reactivity descriptors of BIC and GABA have been discussed. ► Condensed Fukui functions and HOMO-LUMO gap for bicuculline and GABA receptor are computed.