2-oxo-2H-pyrimido[2,1-b]benzothiazoles inhibit brain benzodiazepine receptor binding in vitro

2-Oxo-2H-pyrimido[2,1-b]benzothiazole derivatives were found to inhibit the in vitro binding of H-3-Ro 15-1788 (H-3-flumazenil) to rat cortical benzod iazepine receptors with IC50 values in the range of 0.7-13 mu mol/l. The mo st potent compound, 2-oxo-4-phenyl-2H-pyrimido[2,1-b]benzothiazole showed a similar potency to inhibit 3H-Ro 15-1788 binding to membrane preparations of rat brain cortex, cerebellum and hippocampus as well as to various subun it combinations of recombinant human gamma-aminobutyric acid(A)/benzodiazep ine receptors, Scatchard plot analysis showed that 2-oxo-4-phenyl-2H-pyrimi do[2,1-b]benzothiazole is a competitive inhibitor of 3H-Ro 15-1788 binding to rat brain cortical membrane preparations, Copyright (C) 2000 S. Karger A G, Basel.