Interaction of Amino Acid Schiff Base Metal Complexes with DNA/BSA Protein and Antibacterial Activity: Spectral Studies, DFT Calculations and Molecular Docking Simulations

Abstract

Cu(II), Ni(II) and Zn(II) complexes of (E)-2-((2,4-dihydroxybenzylidene) amino)-3-(1H-indol-3-yl)propanoic acid Schiff base (L) were synthesized and characterized by various spectral methods. ESI-MS was used to confirm the structure of synthesized compounds. Molecular geometries of the complexes were predicted by optimizing the structure by DFT/B3LYP method with LANL2DZ basis set in the gas phase. The interaction of the metal complexes with CT-DNA and BSA protein has been examined by UV-vis, fluorescence and viscometer titrations reveal that the complexes bind to DNA through intercalation binding mode. The copper complexes exhibit effective cleavage of pUC19 DNA by the oxidative mechanism. The synthesized compounds screened for their antibacterial activities against various bacteria strains exhibit the L and copper complex show potential activity against Pseudomonas aeruginosa and Escherichia coli, respectively. Subsequently, molecular docking studies were performed on to understand the binding of the compounds with DNA, BSA and bacteria. KEYWORDS amino acid Schiff base, antibacterial activity, DFT calculations, DNA binding and cleaving, metal complexes

New “one‐pot” Pd(II) and Zn(II) complexes of Schiff bases, derivatives of 1‐amino‐1‐deoxy‐d‐sorbitol: Spectroscopic studies and biological and catalytic activities

“…420–410 cm −1 and ca. 480–460 cm −1 assigned to v (Me‐O) and v (Me‐N), respectively, and the shift of the v (C=N) vibration toward lower frequencies due to the coordination of the metal ion to the nitrogen confirmed the formation of the corresponding complexes . Also sharp bands in the range 1460–1200 cm −1 after the coordination of the metal indicated a change of the structure and complex formation.…”

“…260 nm assigned to the OH form were observed . Coordination of the zinc(II) and palladium(II) caused the disappearance of the band at ~400 nm and bathochromic shift of the one of the high energy bands to ~390 nm, typical of complex formation …”

“…1630 cm −1 and ca. 1600 cm −1 (Table and supporting information) in the region typical for v (C=N) vibration coupled with v (C=C) vibrations . Broad absorption bands at ca.…”

“…One of the reasons for the synthesis of new Schiff base complexes, derivatives of amino sugar, was their potential for biological activity . According to Silva et al ., Schiff bases are promising candidates for the design of new antifungal agents.…”

“…Imines are formed as intermediate products in biologically important reactions . Complexes of Schiff bases play an important role in the detection of various ions, exhibit biological properties, and are widely used as catalysts . Recently, several studies focused on Schiff bases and their complexes, derivatives of natural products, for example, amino sugars, amino acids, and chitosan .…”