Synthesis and biological evaluation of benzimidazolone bridged triheterocyclic compounds

A new series of benzimidazolone bridged triheterocyclic compounds bearing thiosemicarbazide, thiadiazole, triazole, moieties was synthesized and then screened for their in vitro urease, alpha-glucosidase, and acetylcholinesterase inhibition properties for the first time. All the synthesized compounds showed an outstanding urease inhibitory effect when compared with standards. Compounds 1, 4, 5b, 5d, 6b, 6d, 7b, and 7d showed significant acetylcholinesterase inhibitory activity with IC50 values between 7.32 +/- 0.58 and 12.52 +/- 0.13 mu g/ml comparable to donepezil (15.12 +/- 0.20 mu g/ml). Compound 5c, having thiosemicarbazide moiety at the positions N-1 and N-3 of benzimidazolone nucleus, showed the highest alpha-glucosidase inhibitory activity (IC50 = 11.42 +/- 0.11 mu g/ml).