Synthesis and evaluation of novel benzimidazole derivative [Bz-Im] and its radio/biological studies.

Two different benzimidazole analogues act as multimodal agent, first one as novel non-peptidic CCK-B receptor antagonist and similarly as potent anti-fungal agent, designated as [Bz-Im]. These compounds were synthesized and characterized by spectroscopic techniques such as FT-IR, NMR, EI-MS and also evaluated for specific radiopharmaceuticals. Preliminary radiolabeling results with (99m)Tc and biological evaluation studies showed promising results for further evaluation in vivo. The efficiency of labeling was more than 97% and complex was stable for about 12h at 30 degrees C in the presence of serum. Both ligands showed binding to most of the organs, known to express CCK receptors in biodistribution studies. Cholecystokinin (CCK(1) andCCK(2)) receptor binding affinities of these analogues are, IC(50), 0.942+/-0.107 for compound C and 0.665+/-0.211 for compound D in rat pancreatic acini. The anti-fungal activity has shown inhibitory activity against Aspergillus flavus and Aspergillus niger. These studies have provided a new template for further development of non-peptidic ligands for diagnostic and therapeutic purposes of diseases related with CCK receptors as well as anti-microbes.