Rituparna Palit et al / Int. J. Res. Ayurveda Pharm. 7(6), Nov - Dec 2016 68 Review Article www.ijrap.net BENZIMIDAZOLE: AN OVERVIEW Rituparna Palit 1 *, Rajesh Kumar 2 , Nikita Saraswat 1 , Ankita Wal 3 , Prabhat Kumar Upadhyaya 4 1 Assistant Professor, Department of Pharmacy, Pranveer Singh Institute of Technology, Kanpur, U.P, India 2 Student, Department of Pharmacy, Shri Ram MurtiSmarak College of Engineering and Technology, Bareilly, U.P, India 3 Associate Professor, Department of Pharmacy, Pranveer Singh Institute of Technology, Kanpur, U.P, India 4 Assistant Professor, Institute of Pharmaceutical Research, GLA University, Mathura, U.P., India Received on: 04/10/16 Revised on: 15/11/16 Accepted on: 02/12/16 *Corresponding author E-mail: rituparna.palit32@gmail.com DOI: 10.7897/2277-4343.076243 ABSTRACT Benzimidazole derivatives are versatile nitrogen containing heterocyclic compounds which have long been known as a promising class of biologically active compounds possessing wide variety of biological and pharmacological activities like antibacterial, anti-inflammatory, anti-ulcer, anti-diabetic etc. Scientists have elucidated that Benzimidazole system possesses the variable sites like position 2 and 5 which can be suitably modified to yield potent therapeutic agents.The present review covers the chemistry and pharmacological activities of substituted bezimidazoles. Keywords: Benzimidazole, anti-fungal, anti-histaminic, anti-convulsant, anti-inflammatory, analgesic, anti-viral, anti-oxidant, anti-cancer and anti- ulcerative. INTRODUCTION Benzimidazole is as aromatic heterocyclic organic compound. The synthesis of benzimidazole based polyheterocycles draw the attention of pharmacists from last few decades as it functions as an important pharmacophore in medicinal chemistry and pharmacology. Basically, benzimidazole is a bicyclic compound consisting of the fusion of benzene with imidazole which ultimately gives a privileged structure. This magical moiety possesses many pharmacological properties. Till now the most prominent benzimidazolemoiety is N-ribosyl- dimethylbenzimidazole present in nature and it serves as the axial ligand for cobalt in vitamin B 12 . 1 N N H Benzimidazol e Benzimidazolepossess many biological activities such as anti- microbial, anti-fungal, anti-histaminic, anti-inflammatory, anti- viral, anti-oxidant, anti-cancer, anti-ulcerative etc., that’s why benzimidazole derivatives are considered as an important moiety for the development of molecules of pharmaceutical interest. 2,3 There is biological relevance of many heterocyclic building blocks is due to the structural similarity to purine nucleobase and as benzimidazole derivative also which selectively inhibits the endothelial cell growth and then suppresses the process of angiogenesis in vitro as well as in vivo. 3 In addition to this activity, substituted benzimidazoles plays the role of potent inhibitors of parietal cell H + /K + ATPase (proton pump). 4 Moreover, a benzimidazole when substituted with proline bis- amide, it is helpful in curing insomnia and promotes sleep; it acts as a potent orexin inhibitor which was found from high throughput screening. Orexins plays a wide range of functions in CNS which includes regulation of normal sleep-wake cycle and feeding behaviors. Patients of narcolepsy have seen with a disfunctioning of neurons responsible for orexin production. 5 Benzimidazoles when substituted with aminothio carbamoyl hydrazine carbonyl, 1,3,4-thiadiazole and 4H-1,2,4-triazole at 1 st position via a methyl chain and the 2 nd position is substituted with phenyl, p-chlorophenyl, p-methoxyphenyl and pyridinyl rings then the derivatives of benzimidazolemoiety shows potent antioxidant properties. 6 The planar chromophoric ability of benzoannulatedbenzimidazole such as benzimidazo [1,2- a]quinolines or benzimidazo[1,2-a]quinazolines have the ability to get inserted between adjacent base pairs of DNA molecule in the intercalation process and also they can be used as fluorescent probes in assays(homogeneous) of biological molecules. 7 Some reports suggested that benzimidazoles substituted with hydrogen at 1 st position were found active against E.histolytica. 8 PHARMACOLOGICAL ACTIVITIES Anti-inflammatory activity Suresh et al., (2011) synthesized derivatives having thiophene nuclei bind with benzimidazole moiety 1. Newly synthesized compounds were then screened for anti-inflammatory activity and showed significant effect when compared with standard Diclofenac sodium. 9