Schiff bases have a variety of applications in biological, clinical, and pharmacological areas. The synthesis and application of Schiff bases and their coordination compounds have been highly considered in inorganic, organic and biological fields, since their structural properties similar to some of the biological systems.1-6) Additionally, tetradentate Schiff bases composed of N 2 O 2 donor atoms set have been recognized as a kind of important chelating ligands for designing medicinally and catalytically useful metal complexes. [7][8][9] The flexible coordination behavior of these types of chelating ligands could also be useful to generate interesting dimeric and polymeric structures as synthones for supramolecular chemistry. 10,11) Usually, the N, O donor heterodentate Schiff bases can be derived by condensing the aldehydes/ketones with various amines or amino acids. 12,13) N 2 O 2 Schiff base ligands derived from salicylald ehyde and diamine have been known. 14,15) Dialdehydes and diketones with amines and amino acids have also been utilized to obtain a variety of N 2 O 2 Schiff base ligands. 16)Amino acids plays an important role in many physiological activities of the human body and also helpful in understanding biological functions of macromolecules such as proteins. 17) In particular, tryptophan (Trp)/histidine (His) analogues as promising candidates for novel antimicrobial therapeutics. In the recent years, a series of synthetic peptide analogues based on Trp-His and His-Arg (antimicrobial peptides) structural frameworks have been prepared and found to be active against several Gram-positive and Gram-negative bacterial strains as well as against fungal strains.18) Furthermore, it is well known that the human body contains essential metaloelements which play important roles and interact with many biological molecules to fully understand the physiological functions by studying their chemistry coordination and behavior. 17,18) In the present studies we have introduced an azomethine (Schiff base) linkage to tryptophan/histidine, which may permit a variety in their coordination behaviour and complexation role.In previous studies, we have described the synthesis, catalytic and biological applications of Schiff bases and their metal complexes derived from o-phthalaldehyde (OPA) with various amines. [19][20][21][22][23][24][25][26][27] In this respect, we have also developed some useful macrocyclic Schiff bases and their metal complexes. Results from these studies have also shown that complexation of metals with Schiff base ligands serves to improve their antimicrobial activity. There are few other research groups also reported the importance of Schiff base chemistry of the combination of o-phthalaldehyde with amines.28,29) However, a careful literature survey reveals that Schiff bases from the combination of amino acids and o-phthalaldehyde and their coordination behavior towards the transition elements have yet not been studied. The combination of dialdehyde i.e. o-phthalaldehyde and aminoacids is expected to ...