Isolation and Identification of "Diazepam-Like" Compounds From Bovine Urine

Abstract
Attempts to isolate the putative endogenous ligand for the benzodiazepine receptor from bovine urine resulted in the identification of 3 isoflavans: equol (1), 3'',7-dihydroxyisoflavan (2) and 4''-hydroxy-7-methoxyisoflavan (9), as diazepam-like compounds. 3-Chloro-9H-carbazole (17) enhanced the binding of diazepam in the benzodiazepine receptor binding assay. Pinosylvine monomethyl ether (18), indigo (20) and indirubin (21) were isolated as inactive compounds.