Current scenario of tetrazole hybrids for antibacterial activity.

The incidence of invasive bacterial infections has increased remarkably over the past two decades, which was mainly attributed to the increasing emergence of drug-resistant bacteria especially multidrug-resistant strains, intractable pathogens and newly arising pathogenic organisms. Tetrazoles, the bioisoster of carboxylic acid, possess considerable antibacterial property. Hybridization of tetrazole with other antibacterial pharmacophores has the potential to enhance the efficacy against both drug-sensitive and drug-resistant pathogens. Some tetrazole hybrids such as tetrazole-oxazolidinone hybrid Tedizolid 25 and Tedizolid phosphate 26 have already been marketed for the treatment of acute bacterial skin and skin structure infections caused by various bacteria. DA-7867 (27), the amide analog of Tedizolid, also exhibited promising activities against a panel of clinically important pathogens including drug-resistant organisms, demonstrating the possible utility of the tetrazole scaffolds in the development of new antibacterial agents. Thus, hybridization of tetrazole with other antibacterial pharmacophores represents a promising strategy to develop novel antibacterial candidates. This work is attempted to systematically review the research of tetrazole hybrids in the design and development of antibacterial agents during the past two decades. The structure-activity relationship (SAR) is also discussed to provide an insight for rational design of more effective tetrazole antibacterial candidates.