Solid state synthesis, characterization, anti-oxidant and anti-microbial studies of some guanine complexes

Abstract

Metal (II) carbonates (Mn, Ni, Zn) were ground mechanochemically to produce guanine complexes.. Elemental analysis, infrared spectroscopy, melting/decomposition temperature determination and conductivity tests were used to characterize the synthesized complexes. The infrared spectroscopic analysis of the ligand shows a peak at 1674cm^-1 which can be assign to the presence of azomethane in guanine while the shift to1566-1640 cm^-1 confirmed bond formation from azo-group to metal, while the appearance of new peak at 559-592cm^-1 and 440-452cm^-1 was due to deprotonated amine(-NH) and ring nitrogen respectively confirm complexation. The guanine ligand's melting point temperature of 3600C indicates its stability at high temperatures, whereas the complex's decomposition temperature of over 3600C indicates its extreme stability. Comparing the complexes to the theoretical values, conductivity measurement reveals that they are non-electrolytic (29.0-60.6 × 10^-6 Ω^-1cm² mol^-1). At high concentrations (4000 μg/disc and 500 μg/disc), the ligand and its corresponding complexes demonstrated antimicrobial properties against a variety of bacteria and fungi, and their anti-oxidant activity was assessed using the IC50 range (0.00–98.4μg/ml).