Novel N-Heterocyclic Carbene Silver(I) Complexes: Synthesis, Structural Characterization, Antimicrobial and Cytotoxicity Potential Studies
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
Authors: Slimani, Ichraf; Chakchouk-Mtibaa, Ahlem; Mellouli, Lotfi; Mansour, Lamjed; Ozdemir, Ismail; Gurbuz, Nevin; Hamdi, Naceur
Abstract
In this study, a series of unsymmetrical N,N-disubstituted benzimidazolium salts were synthesized as N-heterocyclic carbene (NHC) (2a-2j) and their Ag-I complexes. Their structures were characterized by elemental analyses, H-1 and C-13 nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy techniques. Further, both the salts and their silver(I)-NHC complexes have been evaluated for their potential antibacterial properties against a panel of bacterial strains namely, Micrococcus luteus, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus and Pseudomonas aeruginosa. The results show that silver complexes are effective against Salmonella Typhimurium, Listeria monocytogenes, and Micrococcus luteus with moderate to high activity, and their minimum inhibitory concentrations ranging from 0.0034 to 1.26 mg mL(-1). In addition, the benzimidazoles salts 2a-2j and silver-NHC complexes 3a-3j were screened for their antitumor activity. Complex 3e exhibited the highest antitumor effect with half-maximal inhibitory concentration (IC50) value of 4.2 mu g mL(-1) against MCF-7.
Characterization and protective efficacy of a sptP mutant of Salmonella Paratyphi A
IMMUNITY INFLAMMATION AND DISEASE
Authors: Pan, Pengtao; Zou, Fanyu; He, Chuanshan; He, Qunli; Yin, Junlei
Abstract
Background Salmonella Paratyphi A causes paratyphoid A, a severe systemic disease of people and remains a major public health problem in many parts of the world. In the interest of researching the roles of sptP on Salmonella Paratyphi A and developing a live-attenuated vaccine candidate, an sptP mutant of Salmonella Paratyphi A SPA017 (SPA017 Delta sptP) was constructed, and then its characterization, immunogenicity, and protective ability were evaluated. Results The deletion of sptP had no effect on growth and biochemical properties. Adhesion and invasion assays showed that the lack of sptP did not affect the adhesion of Salmonella Paratyphi A, but the invasive ability of the mutant strain was significantly decreased, the half-lethal dose (LD50) of the mutant strain was 1.43 x 10(4) times of the parent strain in intraperitoneally injected mice. Single intraperitoneal vaccination with SPA017 Delta sptP (1 x 10(5) CFU) in mice did not affect the body weight or elicit clinical symptoms relative to the control group, SPA017 Delta sptP bacteria were isolated from livers and spleens of vaccinated mice at 14 days postvaccination. Notably, specific humoral and cellular immune responses were significantly induced. The protective assessment showed that the mutant strain could provide high-level protection against subsequent challenge with the wild-type SPA017 strain. Conclusions These results demonstrated that SptP plays an essential role in the pathogenicity of Salmonella Paratyphi A, and Salmonella Paratyphi A lacking sptP is immunogenic and protective in mice.