Regioselective synthesis of 5′-amino acid esters of some nucleosides via orthogonal protecting protocol

Nicotinamide riboside-amino acid conjugates that are stable to purine nucleoside phosphorylase

The nutraceutical Nicotinamide Riboside (NR), an efficacious biosynthetic precursor to NAD, is readily metabolized by the purine nucleoside phosphorylase (PNP). Access to the PNP-stable versions of NR is difficult because the glycosidic bond of NR is easily cleaved. Unlike NR, NRH, the reduced form of NR, offers sufficient chemical stability to allow the successful functionalisation of the ribosyl-moiety. Here, we report on a series of NRH and NR derived amino acid conjugates, generated in good to excellent yields and show that O5'-esterification prevents the PNP-catalyzed phosphorolysis of these NR prodrugs.

Uptake and efflux of FL118 and two FL118 derivatives in 3D cell model

Drug uptake and efflux are two of the critical factors required in order to be able to define drug efficacy. This study aims to investigate cytotoxicity and uptake mechanisms of two FL118 analogues (7-Q20 and val-FL118) in parallel with FL118 in three-dimensional multi-cellular spheroids model. The influence of compound concentration, time, temperature, cell lines, and the inhibitors of P-gp, BCRP and LAT1 on drug uptake and efflux were investigated. In vitro cytotoxicity studies revealed that FL118, 7-Q20 and val-FL118 exhibited sensitive cytotoxicity to the HCT-116 cell line and the water-soluble compound 7-Q20 showed the lowest IC50. Cellular uptake and efflux of FL118 was independent of efflux pump proteins. Uptake and efflux of 7-Q20 were affected by P-gp, which was one of reasons that caused a lower uptake at 37 °C than at 4 °C. The carrier protein LAT1 played a role in the cellular intakes of val-FL118. These findings provided basic information for FL118 and the two novel FL118 derivatives for further development.

Synthesis of a Novel Series of Amino Acid Prodrugs Based on Thienopyridine Scaffolds and Evaluation of Their Antiplatelet Activity

The thienopyridines class of drugs used as P2Y₁₂ receptor antagonists plays a vital role in antiplatelet therapy. To further optimized this compound class, we designed and synthesized a series of amino acid prodrugs of 2-hydroxytetrahydrothienopyridine. All compounds were then evaluated for their inhibitory effect on ADP-induced platelet aggregation in rats and then ED₅₀ and bleeding time of the most potent compounds were compared with commercial drugs. The results showed compound 5c could be a potent and safe candidate for further research.