title: Molecular hybridization approach of bio-potent CuII/ZnIIcomplexes derived from N, O donor bidentate imine scaffolds: Synthesis, spectral, human serum albumin binding, antioxidant and antibacterial studies.
abstract: Novel bio-relevant monometallic Schiff base complexes of the type, [Cu(L1)2] (1), [Zn(L1)2]·2H2O (2), [Cu(L2)2]·2H2O (3) and [Zn(L2)2]·H2O (4) [L1(E)-3-(((3-chloro-4-hydroxyphenyl)imino)methyl)naphthalen-2-ol and L2(E)-2-chloro-4-((1-(5-chloro-2-hydroxyphenyl)ethylidene)amino)phenol] were synthesized and characterized. A comparative account of analytical, spectroscopic (FT-IR,1H and13C NMR, Mass, UV-vis and EPR), thermal (TGA/DTA), XRD and SEM studies revealed a correlation between the structure and function of these biologically active molecular entities. HSA (Human serum albumin) binding profiles of the metal complexes (1-4) were monitored using biophysical techniques viz., absorbance, fluorescence, circular dichromism (CD) and foster resonance energy transfer (FRET). The intrinsic binding constant (Kb) demonstrated substantial binding propensity of L1linked complexes (1 and 2) in comparison to L2complexes (3 and 4) suggesting L1to be more bio-active pharmacophore due to higher planarity and conjugation as compared to L2ligand. The outcome of fluorescence study revealed static quenching mechanism on the basis of the quenching of HSA by the complexes (1-4). However, modifications in the secondary structure of HSA by complexes (1-4) inferred via CD measurements which revealed the enhancement of α-helicity (67.47% to 69.20%) with the preference order of 1>2>3>4. Furthermore, in-vitro antibacterial study against different bacteria and antioxidant activities against DPPH and superoxide radical (O2-) at variable concentrations outspread discernible bio-potencies of the metal complexes as compared to free ligand scaffolds due to the chelation effect.
authors: Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India. Electronic address: shakir078@yahoo.com.
authors: Mohammad
authors: M
authors: Shakir
authors: Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India.
authors: Summaiya
authors: S
authors: Hanif
authors: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
authors: Md Fazle
authors: MF
authors: Alam
authors: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
authors: Hina
authors: H
authors: Younus
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D013057:Spectrum Analysis / Q000379:methods; D013818:Thermogravimetry; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D007097:Imines; D012709:Serum Albumin; D003300:Copper; D015032:Zinc
keywords: Antioxidant; Human serum albumin; Metal complexes; Schiff base; Spectroscopic studies