Abstract

STRUCTURAL AND INSILICO STUDIES ON HYDRAZINIUM AND AMMONIUM SALTS OF ETHYLENEDIAMINETETRAACETIC ACID AND 1,2-TRANS CYCLOHEXANEDIAMINETETRAACETIC ACID

B. N. Sivasankar* and C. Sonia

Abstract

Neutralization reaction in aqueous medium between ethylenediaminetetraacetic acid (H4EDTA) and a mixture of weak bases such as hydrazine hydrate and aqueous ammonia yielded a new salt, N2H5H3EDTA.2NH3.H2O. The X-ray single crystal structure of this salt has been determined which reveals that it is composed of one discrete N2H5 + and H2EDTA2- ions along with two ammonia and one water molecules. Both the tertiary nitrogen atoms of EDTA are protonated resulting in the zwitter ion structure. Hydrazinium and ammonium salts of H4EDTA and H4CDTA such as (N2H5)2H2EDTA, N2H6H2EDTA, N2H5H3CDTA.H2O and NH4H3CDTA.2H2O have also been prepared by the reported methods and all the salts were subjected to insilico studies to determine their protein binding efficiencies. The structure of all the salts were MM2 optimized using Discovery studio version 3.5. The bio availability of synthesized compounds and the control, erlotinib were assessed for ADME and Lipinski’s rule of five. The 3D crystal structure of protein (PDB ID: 1M17) was retrieved from Protein Data Bank. Among the five compounds screened, two compounds, N2H6H2EDTA and NH3H3CDTA.2H2O show very good binding affinities as evident from their dock scores and values and also from their ADME and TOPKAT properties. CCDC No: CCDC 1033967.

Keywords: Hydrazinium cation, X-ray crystallography, Zwitter ion, ligand docking, dock score.