Role of Schiff Base in Drug Discovery Research

Abstract

Compounds having imine or azomethine (-C=N-) functional group are known as Schiff bases. They were first reported in 1864 by German Chemist, Hugo Schiff and hence they are named so. For the synthesis of Schiff base, a number of methods have been described in literature. These are now synthesized by a simple one pot condensation of an various amines/hydrazides with carbonyl compounds, water is eliminated during condensation process. As shown in Figure 1, Schiff bases are synthesis from simple reaction between acetone and primary amine. Water is byproduct in this reaction. Other name for Schiff bases are imine or azomethine. Schiff bases form an backbone for large number of organic compounds and have a enormous applications in many fields. Structurally these are nitrogen derivatives of carbonyl compounds in which the (C=O) group has been replaced by an (C=N) group. Schiff bases have also received a great attention because of their potential biological activities such as anti-inflammatory, analgesic, antimicrobial, anticancer, antioxidant and so forth. Schiff Bases are the precursors of countless versatile organic processes for the production of intermediates/products and in making carbon-nitrogen linkage. Synthesis, characterization and structure activity relationship (SAR) of Schiff bases are been studied worldwide. Several studies showed that the presence of a lone pair of electrons in sp 2 hybridized orbital of nitrogen atom of the azomethine group is of considerable chemical and biological importance [1]. They interferes in normal cell processes by the formation of a hydrogen bond between the active centers of cell constituents and sp 2 hybridized nitrogen atom of the azomethine group [2,3]. Schiff bases also have other potential applicability as catalysts, intermediates in organic synthesis, dyes, pigments, polymer stabilizers [4], and corrosion inhibitors [5]. Several Studies show that metal complexes of schiff base are more potent than free organic ligand [6]. Lots of researchers reported that addition of transition metals into Schiff bases increases its biological activity [7]. In coordination chemistry, Schiff bases has key role in design and development of novel compounds having potent biological activities. Schiff bases are the intermediates in organic reactions and are further explored for their utility. Schiff base and their derivatives has attracted the attention of researchers for exploring various processes for development of new environmental-friendly technology [8]. In medicinal field, due to chemotherapeutic applications Schiff bases is now attracting the attention of researchers. They are known to exhibit a variety of potent activities. Parveen and Arjmand [9] have reported the interaction of calf thymus (CT) DNA with a new asymmetric copper(II) N,N-ethane bridged N 2 S 2 macrocycle [2].