Synthesis, characterisation and biological activity of diorganotin compounds of (E)-N'-(5-nitro-2-hydroxybenzylidene)-3-hydroxy-2-naphthohydrazide

Abstract

Diorganotin(IV) compounds with the general formula R2SnL [H2L = (E)-N’-[1-(5-nitro-2-hydroxybenzylidene]-3-hydroxy-2-naphthohydrazide; R = Me (1.toluene and 1), n-Bu (2), Ph (3), Cy (4), Bz (5), o-ClBz (6) and p-ClBz (7)] have been synthesised and characterised by elemental analyses, IR, 1H, 13C{1H} and 119Sn NMR spectroscopy, thermal analysis and in the cases of 1 and 3, single crystal X-ray diffraction. Crystallography, in accord with NMR, indicate highly distorted penta-coordinate geometries whereby each C2NO2 donor set is defined by the NO2 donor atoms derived from di-anionic L and two tin-bound organo substituents. The Schiff base ligand and the corresponding diorganotin compounds have been evaluated against two colon human carcinoma cell lines (HT-29 and HCT 116) and a normal colon fibroblast cell line (CCD-18Co). Among the evaluated compounds, the n-butyl derivative, 2, is most potent and least toxic to the cancer and normal cell lines, respectively, yielding the highest safety profile (high SI). In addition, the anti-bacterial activities have been evaluated against a panel of 21 Gram positive and Gram negative bacteria. Based on the broth dilution method, non-toxic 3, exhibited promising anti-bacterial effects against two Gram positive bacteria, namely, Enterococcus faecalis and Staphylococcus epidermidis.