Homo- and heteroleptic Zinc(II) carboxylates: Synthesis, structural characterization, and assessment of their biological significance in in vitro models

Abstract

A series of five new zinc(II) complexes of 2-phenylbutyric acid comprising of one homoleptic (1) and four heteroleptic (2–5) complexes were synthesized under open beaker conditions. The behavior of the complexes in the solid and solution state was explored through FT-IR and NMR (1H and 13C) spectroscopy, respectively. Crystallographic data have revealed that complexes 2 and 3 crystallized in monoclinic and triclinic crystal system, respectively, with a distorted octahedral geometry, whereas complex 4 crystallized in monoclinic crystal system with a pentagonal geometry around the zinc(II) atom. All the complexes have been screened for enzyme (alkaline phosphatase) inhibition, in vitro hemolysis and antileishmanial activity, DNA and cetyltrimethylammonium bromide (CTAB) interaction. The increase in the concentration of complexes 1, 2, 4 and 5 remarkably decreases the activity of enzyme alkaline phosphatase, whereas complex 3 was found inactive. The behavior of the complexes as a potent drug is clear from the results of hemolysis and antileishmanial activity against promastigote. The UV–Vis spectroscopic data of complexes–DNA interactions suggested a surface binding mode whereas the interaction of CTAB with complexes, studied through conductometry, confirmed strong interacting ability of complexes with CTAB.