Design and synthesis of novel anti-multidrug-resistant staphylococcus aureus derivatives of glycyrrhetinic acid by blocking arginine biosynthesis, metabolic and H2S biogenesis.

With the soaring number of multidrug-resistant bacteria, it is imperative to develop novel efficient antibacterial agents and discovery new antibacterial pathways. Herein, we designed and synthesized a series of structurally novel glycyrrhetinic acid (GA) derivatives against multidrug-resistant Staphylococcus aureus (MRSA). The in vitro antibacterial activity of these compounds was evaluated using the microbroth dilution method, agar plate coating experiments and real-time growth curves, respectively. Most of the target derivatives showed moderate antibacterial activity against Staphylococcus aureus (S. aureus) and MRSA (MIC = 3.125-25 µM), but inactivity against Escherichia coli (E. Coli) and Pseudomonas aeruginosa (P. aeruginosa) (MIC > 200 µM). Among them, compound 11 had the strongest antibacterial activity against MRSA, with an MIC value of 3.125 µM, which was 32 times and 64 times than the first-line antibiotics penicillin and norfloxacin, respectively. Additionally, transcriptomic (RNA-seq) and quantitative polymerase chain reaction (qPCR) analysis revealed that the antibacterial mechanism of compound 11 was through blocking the arginine biosynthesis and metabolic and the H2S biogenesis. Importantly, compound 11 was confirmed to have good biocompatibility through the in vitro hemolysis tests, cytotoxicity assays and the in vivo quail chicken chorioallantoic membrane (qCAM) experiments. Current study provided new potential antibacterial candidates from glycyrrhetinic acid derivatives for clinical treatment of MRSA infections.

[Association of rs1495741 Single Nucleotide Polymorphism with Susceptibility of Anti-tuberculosis Drug-induced Hepatotoxicity].

OBJECTIVE: To investigate the potential association between the polymorphism of N- acetyltransferase 2 (NAT2) gene and anti-tuberculosis drug-induced hepatotoxicity (ATDH) in Han population. METHODS: The SNP rs1495741 was genotyped by using multiplex ligation detection reaction (MLDR) technique, and logistic regression analysis was used to analyze the association between this SNP and the susceptibility of ATDH. RESULTS: There were 247 PTB patients enrolled in this study, including 24 ATDH, and 223 controls (PTB without ATDH). No significant difference in genotype and allele distribution was observed for rs1495741 in NAT2 between the controls and ATDH group. After adjusting age, sex, body mass index (BMI) and smoking history, the SNP of rs1495741 showed a significant association with ATDH 〔odds ratio (OR)=2.728 (95% confidence interval: 1.022-7.281)〕 under recessive model (AA vs. GA+GG). CONCLUSIONS: The rs1495741 in NAT2 seems related to the development of ATDH among PTB patients, AA genotype of rs1495741 may be a causative factor for increased susceptibility to ATDH.

[Advances in Microbial Degradation and Transformation of Per- and Polyfluoroalkyl Substances(PFASs)].

Per- and polyfluoroalkyl substances (PFASs) have attracted extensive attention because of their persistence, long-distance migration ability, bioaccumulation, and biological toxicity. Currently, regulatory strategies concerning PFASs in the environment primarily focus on perfluoroalkyl acids (PFAAs). However, most polyfluoroalkyl compounds can be degraded to PFAAs by environmental microorganisms, also known as precursors. Exploring the microbial transformation behavior of precursors is fundamental to comprehensively evaluate the environmental risk of PFASs and formulate control and remediation schemes of PFAS-contaminated sites. Furthermore, anaerobic microbial reductive defluorination of PFAAs is a potential and challenging remediation technology. This review summarizes degradation rules and transformation pathways of precursors (fluorotelomer compounds and perfluorooctane sulfonamide derivatives), PFAAs, and novel PFASs by microorganisms and discusses factors affecting the microbial degradation. Finally, the future research directions are put forward.