Design Synthesis and Biological Evaluation of Novel Antimicrobial Agents

Abstract

Drug discovery begins with identification of New Chemical Entities (NCEs) with demonstrated activity against a macromolecular target of interest for a particular therapeutic indication. The NCEs are new chemical matter not previously synthesized and/or tested for any known or unknown biological activity.1 Generally, drug discovery and development process takes ~10-15 years2 and up to 30 years in some cases.3 In drug discovery, NCEs is a chemical moiety found to have potential to be developed as a drug, which can have therapeutic benefit in the form of a treatment or cure for some disease or disorder. newlineMicrobial infections are foremost reason for a death worldwide. Several pathogens threaten the mankind by causing a disease which is very difficult to treat. Such pathogens can be cramped by the use of anti-infective agents- a general term used for a medicine having capability to inhibit the spread of infection causing microorganism or by killing them. newlineThese anti-infective agents are also known as antimicrobial agent- a chemical moiety which is used to treat infections by suppressing or destroying the causative microorganisms. The essence of antimicrobial agents is Selective Toxicity - to kill or inhibit only microbe without affecting host cells. Generally, microbiologists classify antimicrobial agents into two major groups, depending on the source from which they are obtained or prepared, viz., antibiotics and chemotherapeutic agents.4 An antibiotic is a chemical substance obtained from one microorganism that kills or inhibits the growth of other microorganisms. Most of the antibiotics are produced either by fungi (e.g., penicillins, cephalosporins, etc.), Streptomyces species (streptomycin, erythromycin, tetracycline, kanamycin, nystatin, neomycin, etc.) or Bacillus species (e.g., polymyxin, bacitracin, etc.). Chemotherapeutic agents are chemically synthesized in the laboratory.4-5 Nowadays the term antibiotic applies to both substances produced naturally and those synthesized chemically.