Antibiotic 49A

The increasing demand for new and effective antibiotics requires intelligent strategies to obtain a wide range of potential candidates. Laccase-catalyzed reactions have been successfully applied to synthesize new β-lactam antibiotics and other antibiotics. In this work, laccases from three different origins were used to produce new aminoglycoside antibiotics. Kanamycin, tobramycin and gentamicin were coupled with the laccase substrate 2,5-dihydroxy-N-(2-hydroxyethyl)-benzamide. The products were isolated, structurally characterized and tested in vitro for antibacterial activity against various strains of Staphylococci, including multidrug-resistant strains. The cytotoxicity of these products was tested using FL cells. The coupling products showed comparable and, in some cases, better antibacterial activity than the parent antibiotics in the agar diffusion assay, and they were not cytotoxic. The products protected mice against infection with Staphylococcus aureus, which was lethal to the control animals. The results underline the great potential of laccases in obtaining new biologically active compounds, in this case new antibiotic candidates from the class of aminoglycosides.

The thiazolopyrimidine nucleus is a bioisosteric analog of purine and an important class of N-containing heterocycles. Thiazolopyrimidine scaffolds are considered a promising class of bioactive compounds that encompass diverse biological activities, such as antibacterial, antiviral, antifungal, anticancer, corticotrophin-releasing factor antagonists, anti-inflammatory, antituberculosis, and glutamic receptors antagonists. Despite the importance of thiazolopyrimidines from a pharmacological viewpoint, there is hardly a comprehensive review on this important heterocyclic nucleus. Throughout the years, those scaffolds have been studied extensively for its anticancer properties and several compounds were designed, synthesized, and evaluated for their anticancer effects with activity in the μM to nM range. However, there are hardly any reviews covering the anticancer effects of thiazolopyrimidines. In this review, an effort was made to compile literature covering the anticancer activity of thiazolopyrimidines reported in the last decade (2010-2020). Nearly thirty articles were reviewed and compounds with IC50 < 50 μM against at least 50% of the used cell lines were listed in this review. The best ten compounds (10a, 14b, 17g, 18, 25e, 25k, 34e, 41i, 49a and 49c) showing the best anticancer activity against the corresponding cell lines during the last 10 years are highlighted. By highlighting the most active compounds, this review article sheds light on the structural features associated with the strongest anticancer effects to provide guidance for future research aiming to develop anticancer molecules.

Background: Our study aims at assessing the pre-clinical impact of the synergistic mechanism of Daptomycin (DAP) and Ceftaroline (CFT) on patients with Methicillin-Resistant Staphylococcus aureus Bacteremia infections (MRSAB). Methods: A systematic overview was conducted by searching PubMed, Oxford academic, and Cochrane library up to June 2020. Study selection and data extraction: All English- language clinical trials, in vitro studies, and case reports related to the synergistic drug therapy for MRSAB. Results: In the case of MRSAB infections, we examined two different in vitro studies that showed effective synergism with DAP and CFT. The Minimum Inhibitory Concentration (MIC) range observed for each is as follow: DAP 0.125-1 mg/L, CFT 0.38-1 mg/L, DAP + CFT 0.094-0.5 mg/L, vancomycin (VAN) 0.75-2 mg/L, VAN + CFT 0.25-2 mg/L. DAP + CFT combination displayed the most efficacy with the lowest MIC. The statistical analysis performed showed that DAP + CFT obtained significantly lower fractional inhibitory concentration (FIC) values (0.941 ± 0.328) compared with VAN + CFT. In vitro activities of regimens tested on DAP non-susceptibility and VAN intermediate after 96 hours showed DAP 8.29 ± 0.03a log10 CFU/mL, VAN 6.82 ± 0.04a log10 Colony Forming Unit (CFU)/mL, CFT 4.63 ± 0.19a log10 CFU/mL, DAP + CFT 1.15 ± 0.20b log10 CFU/mL, VAN + CFT 3.18 ± 0.49a log10 CFU/mL. (a meaning significantly different than DAP plus CFT, P< equal to 0.001b meaning therapeutic enhancement combination was defined as ≥ 2 log10 CFU/ml reduction over the most active single agent). Based on these results, although DAP was not susceptible, the Colony Forming Unit (CFU) for DAP and CFT had the best therapeutic results. Conclusion: In vitro studies have shown that a combination DAP and CFT is more efficacious than the combination of VAN and CFT in MRSA bacteremia infections. The synergic effects of DAP (bactericidal) and CFT (bactericidal) is statistically significant, in recent trials, warranting promising evidence for its use in complicated bacteremia infection.