Biological Activities of Schiff Bases and Their Complexes: A Review of Recent Works

Schiff base compounds and their metal complexes have been extensively investigated due to their wide range of applications including catalysts [1,2], medicine [3,4] crystal engineering [5], anti-corrosion agent [6,7]. Schiff bases are studied widely due to their synthetic flexibility, selectivity and sensitivity towards the central metal atom; structural similarities with natural biological compounds and also due to presence of azomethine group(-N=CH-) which imports in elucidating the mechanism of transformation and racemization reaction biologically [8,9]. Schiff bases having chelation with oxygen, nitrogen etc. donors and their complexes have been used as drugs and reported to possess a wide variety of biological activities against bacteria, fungi, and certain type of tumors and also, they have many biochemical, clinical and pharmacological properties [10-14]. Imine or azomethine groups are present in various natural, naturally derived and nonnatural compounds (Figure 1). The imine group present in such compounds has been shown to be critical to their biological activities [15-17]. This review concentrates on the synthesis and biologi-