Synthesis, characterization and biological applications of some substituted pyrazoline based palladium (II) compounds

• Published in: Applied organometallic chemistry 2018-11, Vol.32 (11), p.n/a
• Main Authors: Thakor, Khyati P., Lunagariya, Miral V., Bhatt, Bhupesh S., Patel, Mohan N.
• Format: Article
• Language: English
• Subjects: Absorption; Bacteria; Binding; Chemistry; Coordination compounds; cytotoxicity; Deoxyribonucleic acid; DNA; DNA intercalation; E coli; Electrophoresis; ethidium bromide displacement; Fluorescence; Free energy; Infrared radiation; Modelling; mycobacterium tuberculosis; NMR; Nuclear magnetic resonance; Palladium; Plasmids; Resistance; Saline water; Spectroscopic analysis; Spectrum analysis; Substitutes; Thermogravimetric analysis; Titration; Toxicity; Tuberculosis; Viscosity; Viscosity measurement
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.4523

Palladium (II) complexes of the type [PdLCl2] (where L = substituted pyrazoline ligands) have been synthesized. The metal complexes (5a‐5f) have been characterized by various spectroscopic and analytical techniques like 1H‐NMR, 13C‐NMR, LC–MS, IR, Energy‐dispersive X‐ray (EDX), electronic spectroscopy, thermogravimetric analysis (TGA), elemental analysis and conductance measurement. Complexes to herring sperm DNA (HS‐DNA) binding has been explored by absorption titration and binding constant (Kb) as well as Gibb's free energy have been evaluated. Complex 5b shows the highest binding constant value. So, thermodynamic parameters of 5b‐HS DNA complex at different temperature have been evaluated. Also, Viscosity measurement and molecular modeling studies have been performed to know the binding mode of complexes. Based on the observations, an intercalative binding mode of DNA has been proposed. Further confirmation of intercalative mode of DNA binding has been taken by fluorescence spectroscopy and results are in a good agreement with absorption titration, viscosity measurement and molecular modeling data. Antibacterial activity of the complexes has been screened against pathogenic bacteria such as S. aureus, E. coli, B. subtilis, S. marcescens and P. aeruginosa. Cytotoxicity is performed on brine shrimp and S. pombe. Gel electrophoresis assay demonstrates that all the complexes can cleave the pUC19 plasmid DNA. Anti‐tuberculosis activity has been carried out using mycobacterium tuberculosis H37Rv bacteria by L.J. Medium conventional method. Synthesis and characterization of pyrazoline‐based Pd (II) complexes have been carried out as an alternative to platinum‐based drugs. The complexes have been evaluated for diverse biological activities like DNA binding, nucleolytic, antibacterial and antituberculosis activities and cytotoxicity with appropriate methods along with kinetic and thermodynamic parameters.