Synthesis and Evaluation of the Complex-Forming Ability of Hydroxypyranones and Hydroxypyridinones With Ni (Ii) As Possible Inhibitors for Urease Enzyme in Helicobacter Pylori Publisher



Palizban A¹ ; Saghaie L² Show Affiliations
Source: Research in Pharmaceutical Sciences Published:2016

Abstract

The complex-forming ability of 2-methyl-3-hydroxypyran-4-one (1a), 2-ethyl-3-hydroxypyran-4-one (1b), 1,2-dimethyl-3-hydroxypyridin-4-one (4a) and 1-ethyl-2-methyl-3-hydroxypyridin-4-one (4b) with nickel(Ni(II)) were characterized by infrared, ultraviolet, proton nuclear magnetic resonance spectroscopy and melting point. The mole-ratio of nickel:ligands was analyzed by atomic-absorption-spectrometry. The partition-coefficients (KOW) of the compounds were also determined. The binding of ligands with Ni(II) are through deprotonated hydroxyl group (-O-, disapeared at 3259 cm-1) and ioan-pairs of carbonyl group (=CO., shifted from 1650 to 1510-1515 cm-1). The characterization of complex geometry for bis-(2-methyl-3- hydroxypyranonato)Ni(II) (5a) and bis-(2-ethyl-3-hydroxypyranonato)Ni(II) (5b) predicted to be squareplaner while for bis-(1,2-dimethyl-3-hydroxypyridinonato)Ni(II) (5c) and bis-(1-ethyl-2-methyl-3- hydroxypyridinonato)Ni(II) (5d) distorted to tetrahedral-geometry. Inhibitors of Helicobacter pylori urease are nickel chelators. The compounds 1a, 4a and 4b are likely suitable ligands with complex forming-ability to make complexes of 5a, 5c and 5d with nickel. The KOW values show the compound 5c with low partitioncoefficient is more suitable ligand with lower penetration from GI lumen. Future studies demand to find out the biological activity of developed compounds on H. pylori.