Synthesis, spectral, computational and thermal analysis studies of metalloceftriaxone antibiotic

Multidimensional Insights into Organics Stress on Anammox systems: From a "Molecule-Cell-Ecology" Perspective

Anaerobic ammonium oxidation (anammox) is efficient and cost-effective for treating high-strength ammonia wastewater, but the organics in wastewater will affect its stability. To address this challenge, it is crucial to gain a deep understanding of the inhibitory effects and mechanisms of organics stress on anammox bacteria. The review provided a comprehensive classification of organics and evaluated their specific effects on the anammox system according to their respective characteristics. Based on the micro to macro perspective, the "molecule-cell-ecology" inhibitory mechanism of organics on anammox bacteria was proposed. The molecular observation systematically summarized the binding process and action sites of organics with anammox bacteria. At the cellular observation, the mechanisms of organics effects on extracellular polymeric substances, membranes, and anammoxosome of anammox bacteria were also expounded. At the ecological observation, the dynamic changes in coexisting populations and their role in organics transformation were further discussed. Further revelations on response mechanisms and inhibition mitigation strategies were proposed to broaden the applicability of anammox systems for organic wastewater. This review offered a multidimensional understanding of the organics inhibitory mechanism of anammox bacteria and provided a theoretical foundation for anammox systems.

Structure, mechanism, and toxicity in antibiotics metal complexation: Recent advances and perspectives

Antibiotic-metal complexes (AMCs) formed by antibiotics and metal ions have attracted considerable attentions in recent years. Although different removal methods for AMCs have been reported in the literature, very few investigations have focused on the mechanisms and toxic effects of antibiotic-metal coordination. This review briefly describes the structural characteristics of various commonly used antibiotics and the coordination mechanisms with metal ions. Considering the complexity of the real environment, various environmental factors affecting AMC formation are highlighted. The effects of AMCs on microbial community structure and the role of metal ions in influencing resistant genes from the molecular perspective are of interest within this work. The toxicities and mechanisms of AMCs on different species of biota are also discussed. These findings underline the need for more targeted detection and analysis methods and more suitable toxicity markers to verify the combination of antibiotics with metal ions and reveal environmental toxicities in future. This review presents an innovative idea that antibiotics combined with metal ions will change the toxicity and environmental behavior of antibiotics.

Spectral, thermal studies and biological activity of pyrazinamide complexes

Synthesis and spectrothermal characterization of new fabricated pyrazinamide complexes with metal [Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)] salts are reported. The structural chemistry of these complexes is achieved via elemental analysis, spectral (UV, visible, and IR), thermal (DTA and TGA) as well as magnetic susceptibility. In these new octahedral complexes (Zn complex is tetrahedral), pyrazinamide acts as a bidentate ligand. Pyrazinamide complexes show higher activity than pyrazinamide for some strains. The geometry of the complexes is converted from Oh to Td during their thermal decomposition. The decomposition mechanisms are suggested and the thermodynamic parameters for the thermal decomposition steps are evaluated.

Evaluation of the Interaction between the Poincianella pyramidalis (Tul.) LP Queiroz Extract and Antimicrobials Using Biological and Analytical Models

Poincianella pyramidalis (Tul.) LP Queiroz (Fabaceae) is an endemic tree of northeastern Brazil, occurring mainly in the Caatinga. Its medicinal use is widespread and is an important therapeutic option against diarrhea, dysentery, and respiratory and urinary infections, among other diseases. In this study we determined the chemical marker and evaluated the interaction between P. pyramidalis extract and a commercial antimicrobial through the use of biological and analytical models. To obtain the extract, an ethanol-water mixture (50:50 v/v) was used as solvent. It was nebulized in a spray dryer using colloidal silicon dioxide as a drying adjuvant. The extract (ENPp) was subjected to HPLC analysis to verify the presence of certain secondary metabolites. The Minimum Inhibitory Concentration (MIC) of the extract against Gram-negative bacteria was determined by broth microdilution and the MIC of synthetic antimicrobial drugs in the presence and absence of the extract. The antioxidant activity of ENPp was evaluated by the DPPH method. The compatibility between the antimicrobial and the extract was evaluated by thermal analysis (TG/DTA). The acute toxicity of the extract was evaluated in vivo in rodents. The results indicate significant additive action of the extract on synthetic antibiotics, considerable antioxidant activity and absence of toxicity. This extract shows high potential for the development of formulations for antimicrobial therapy when used with a vegetable-active ingredient.