Biologically active Co (II), Cu (II), Zn (II) centered water soluble novel isoniazid grafted O-carboxymethyl chitosan Schiff base ligand metal complexes: Synthesis, spectral characterisation and DNA nuclease activity.

In this study, the new N, N, O tridentate donor water soluble isoniazid based biopolymer Schiff base ligand and their Co (II), Cu (II), Zn (II) metal complexes were prepared. The compounds were designed for potential biological application such as antibacterial, antifungal, anti-inflammatory, total antioxidant, antidiabetic and DNA binding studies. The synthesized compounds were illuminated in different light sources of various spectra were used to explore the functional groups of Biopolymer derivatives. Thermal degradation, thermal stability and percentage of mass loss for the prepared compounds were investigated through thermo gravimetric and differential thermal (TGA-DTA) analyses. Crystalline structure of synthesized biopolymer derivatives were explored by X-ray diffraction (XRD) studies, the crystallinity of chitosan is gradually decreased after the Schiff base and complex formation. Surface morphology and structures of the prepared compounds were examined using SEM analysis. The magnetic moment and magnetism of the metal complexes were studied using Vibrating-sample magnetometer (VSM). Antidiabetic studies of Biopolymer Schiff base and metal complexes were carried out by α-amylose inhibitory method. DNA nuclease activities of synthesized metal complexes were investigated by Ultra-Violet (UV) and viscometry methods. The Cu (II) complexes showed better DNA binding results than Co (II) and Zn (II) complexes.

Synthesis and characterisation of novel Cu(ii)-anchored biopolymer complexes as reusable materials for the photocatalytic degradation of methylene blue.

This study focused on the synthesis, photocatalytic degradation of organic dyes and biological activity of novel N, N, O-donor tridentate water soluble 4-hydroxy benzohydrazide-grafted biopolymer Schiff base Cu(ii) complexes. The eco-friendly catalysts were designed for potential application in the degradation of organic dyes. The photocatalytic degradation of methylene blue was investigated with various irradiation times (30, 60, 90 and 120 min), catalytic dosages (5, 10, 15 and 20 mg) and pH (3, 7 and 12). The as-prepared compounds were characterised via various techniques including FT-IR and FT-NMR spectroscopy; TGA-DTA, XRD, SEM-EDAX; ESR and UV-vis spectroscopy; photoluminescence, magnetic moment, and conductivity measurements; and elemental and thermal analysis. The crystallinity of the Schiff base ligands, chitosan, and their Cu(ii) complexes was analysed via X-ray diffraction (XRD) studies. The XRD patterns revealed that the polymer chitosan was more crystalline than the Schiff base ligands and their complexes. The surface morphological analysis by scanning electron microscopy (SEM) revealed that the Cu(ii) complexes were amorphous in nature compared to chitosan and the ligands. The anti-inflammatory and anti-diabetic studies of the biopolymer Cu(ii) complexes were performed using the albumin denaturation technique and McCue and Shetty method, respectively. The as-synthesized 4-hydroxy benzohydrazide-grafted O-carboxymethyl chitosan Schiff base ligands and their Cu(ii) complexes showed a good anti-inflammatory and antidiabetic effect. The photocatalytic activity proved that the aryl-substituted complex was more efficient than the aliphatic-substituted complex.

Biologically active novel N, N, O donor tridentate water soluble hydrazide based O-carboxymethyl chitosan Schiff base Cu (II) metal complexes: Synthesis and characterisation.

Water soluble hydrazide based O-carboxymethyl chitosan Schiff base ligands have been prepared from chitosan and a mixture of benzoic acidhydrazide with ß-diketone by carboxymethylation using mono chloroaceticacid (MCA) through in-situ reaction. The degree of deacetylation of chitosan was determined by elemental analysis and potentiometric titration. Schiff base ligands and the functional groups were characterised by FT-IR, 1H, and 13C NMR spectroscopic techniques. The crystallinity of ligands and complexes was evaluated by X-ray powder diffraction (XRD) studies. Thermal stability of all the synthesized compounds was investigated by thermo gravimetric analysis and differential thermal analysis (TGA-DTA) which revealed the presence of metal oxide (CuO) residue to elevate the temperature to >500 °C. Filed emission scanning electron microscopic (FESEM) analysis revealed that Cu (II) complexes were more amorphous in nature than chitosan and Schiff base ligands. Vibrating sample magnetometer (VSM) studies reported that the d9 configuration of the metal complex was paramagnetic in nature and the geometry of the complex was square pyramidal. The antimicrobial activity of the synthesized hydrazide Cu (II) complexes was characterised by agar plate method, anti-inflammatory study was characterised by egg albumin denaturation technique and total antioxidant activity was characterised by phosphomolybdenum method.