NHC-diphosphate is an active phosphorylated intracellular metabolite of β-d-N4-Hydroxycytidine (NHC) as a diphosphate form[1]. NHC is a pyrimidine ribonucleoside and behaves as a potent anti-virus agent. NHC effectively inhibits the replication of venezuelan equine encephalitis virus (VEEV), Chikungunya virus (CHIKV) and hepatitis C virus (HCV)[1]. Huh-7 cells are incubated with (10-50 μM; 4 h) NHC or a McGuigan phosphoramidate prodrug of NHC.Intracellular levels of the parental compounds and phosphorylated metabolites are measured using LC-MS MS. Small amounts of NHC-monophosphate (MP) and NHC-diphosphate can be observed, while NHC-triphosphate remains the most abundant metabolite.[1].
NHC-triphosphate triammonium is an active phosphorylated intracellular metabolite of β-d-N4-Hydroxycytidine (NHC) as a triphosphate form[1]. NHC-triphosphate triammonium is a weak alternative substrate for the viral polymerase and can be incorporated into HCV replicon RNA[1][2]. In an intracellular metabolism assay, HCV replicon cells are treated with 10 μM 3H-labeled NHC, and intracellular nucleotide levels are determined after 1, 2 and 8 hours incubations. NHC is rapidly convered into the mono-, di-, and triphosphate forms, and NHC-TP reaches up to 71.12 pM after 8 hours[1].NHC-triphosphate triammonium (NHC-TP) (5-40 μM) absence leads to full-length polymerization products, it can be a weak alternative substrate. In addition, incorporation of NHC-TP instead of CTP increases the molecular weight of the polymerization product by 16 (one extra oxygen) for each event and an obvious electrophoretic shift is observed in cell-free HCV NS5B polymerization reactions[1].Huh-7 cells are incubated with (10-50 μM; 4 h) NHC or a McGuigan phosphoramidate prodrug of NHC. Intracellular levels of the parental compounds and phosphorylated metabolites are measured using LC-MS MS. Small amounts of NHC-monophosphate (MP) and NHC-diphosphate (DP) can be observed, while NHC-triphosphate triammonium remains the most abundant metabolite[2].NHC-triphosphate triammonium (NHC-TP) metabolite may directly target the viral polymerase and behave as a nonobligate chain terminator. It plays a prominent role in inhibiting early negative-strand RNA synthesis, either through chain termination or mutagenesis, which may in turn interfere with correct replicase complex formation. [1]. Stuyver LJ,et al. Ribonucleoside analogue that blocks replication of bovine viral diarrhea and hepatitis C viruses in culture.Antimicrob Agents Chemother. 2003 Jan;47(1):244-54. [2]. Maryam Ehteshami, et al. Characterization of β-d- N4-Hydroxycytidine as a Novel Inhibitor of Chikungunya Virus.
XMU-MP-3 is a robust, non-covalent inhibitor of BTK, exhibiting exceptional potency with IC50 values of 10.7 nM and 17.0 nM for BTK WT and BTK C481S mutation, respectively, in the presence of 10 μM ATP. Moreover, XMU-MP-3 elicits apoptosis.