Studies on meropenem and cefixime metal ion complexes for antibacterial activity

Background The metal ion complexes of meropenem and cefixime with cadmium, silver, palladium, zinc, nickel, cobalt and copper were synthesized and characterized by UV, FTIR and H1-NMR spectrophotometry. The antibacterial effects of the complexes were studied using cup and plate method against S. aureus, B. subtilis, E. coli, P. aeruginosa and K. pneumoniae for normal and resistant strains of bacteria. The minimum inhibitory concentration of the metal ion complexes was determined by broth dilution method. Results UV spectroscopic studies suggested that meropenem ligand form complex with different metal ions and FTIR spectrum confirmed the proposed structure. Similarly, UV spectrum of cefixime metal ion complexes at λmax 202–295 nm and meropenem metal ion complexes at λmax 249–304 nm was observed in all the complexes. FTIR peaks for a proposed structure were observed in all the meropenem and cefixime metal ion, indicating the formation of complexes, and retained the functional groups of drugs. Meropenem as well as cefixime metal ion complexes exhibited more antibacterial activity against all the selected bacterial strains. Specifically, the lowest minimum inhibitory concentration against P. aeruginosa and K. pneumoniae was observed to be 100 and 150 μg/ml, respectively. Conclusion The present study concluded that the meropenem and cefixime metal complexes can exhibit the better treatment than individual drug on normal as well as resistant bacteria.

Roles of metal ions in the selective inhibition of oncogenic variants of isocitrate dehydrogenase 1

Cancer linked isocitrate dehydrogenase (IDH) 1 variants, notably R132H IDH1, manifest a ‘gain-of-function’ to reduce 2-oxoglutarate to 2-hydroxyglutarate. High-throughput screens have enabled clinically useful R132H IDH1 inhibitors, mostly allosteric binders at the dimer interface. We report investigations on roles of divalent metal ions in IDH substrate and inhibitor binding that rationalise this observation. Mg2+/Mn2+ ions enhance substrate binding to wt IDH1 and R132H IDH1, but with the former manifesting lower Mg2+/Mn2+KMs. The isocitrate-Mg2+ complex is the preferred wt IDH1 substrate; with R132H IDH1, separate and weaker binding of 2-oxoglutarate and Mg2+ is preferred. Binding of R132H IDH1 inhibitors at the dimer interface weakens binding of active site Mg2+ complexes; their potency is affected by the Mg2+ concentration. Inhibitor selectivity for R132H IDH1 over wt IDH1 substantially arises from different stabilities of wt and R132H IDH1 substrate-Mg2+ complexes. The results reveal the importance of substrate-metal ion complexes in wt and R132H IDH1 catalysis and the basis for selective R132H IDH1 inhibition. Further studies on roles of metal ion complexes in TCA cycle and related metabolism, including from an evolutionary perspective, are of interest.

Synthesis, Characterization and Magnetic Susceptibility of Novel Transition Metal Ion Complexes with (E)-2-((7H-Purin-6-ylimino)methyl)phenol and Its Antibacterial Efficiency

The novel transition metal ion complexes were synthesized by refluxing the ethanolic solutions of metal acetates with Schiff base in 1:2 ratios. The structure and characterization of synthesized complexes of Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) with Schiff base (E)-2-((7H-purin-6-ylimino)methyl)phenol were elucidated by using 1H NMR, FT-IR and UV-Visible spectroscopic techniques. The synthesized compounds were also been screened against gram positive and gram-negative bacteria. The novel compounds were further carried out for the study of magnetic susceptibility.

Overview of the Antioxidant and Anti-Inflammatory Activities of Selected Plant Compounds and Their Metal Ions Complexes

Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.