Metal complexes of gliclazide: Preparation, spectroscopic and thermal characterization. Biological potential study of sulphonylurea gliclazide on the house fly, Musca domestica (Diptera – Muscidae)

Metal complexes of gliclazide (GLZ; HL) drug are prepared and characterized based on elemental analyses, IR, diffused reflectance, magnetic moment, molar conductance and thermal analyses (TG and DTG) technique. From the elemental analyses data, the complexes are proposed to have the general formulae [M(HL)Cl3(H2O)]·3H2O (M = Cr(III) and Fe(III)), [M(HL)Cl2(H2O)2]·yH2O (M = Co(III), Ni(II) and Cu(II), y = 0–2) and [M(HL)Cl2]·yH2O (M = Mn(II) and Zn(II), y = 0–1). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that GLZ is coordinated to the metal ions in a neutral bidentate manner with ON donor sites of the amide-O and sulphonamide-OH. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral (Cr(III), Fe(III), Co(II), Ni(II) and Cu(II)) and tetrahedral (Mn(II) and Zn(II)). The thermal behaviour of these chelates is studied using thermogravimetric analysis (TG and DTG) techniques. The results obtained show that the hydrated complexes lose water molecules of hydration followed immediately by decomposition of the anions and ligand molecules in the successive unseparate steps. The activation thermodynamic parameters are calculated using Coats–Redfern method. The GLZ drug, in comparison to its metal complexes also is screened for their biological activity against house fly, Musca domestica (Diptera – Muscidae). Dose of 5 μg/insect of gliclazide is typically applied against 3 days-old larval instar of M. domestica. Survival of pupal and adult stages has been affected by the complexes of gliclazide more than larval instars. Morphogenic abnormalities of larvae, pupae and adults are studied. On the other hand, pupation and adult emergence program is deteriorated by the effect of different chemicals.