RESUMEN
Herein we describe the research and development of the process for the scale-up total synthesis of largazole, a potent class I selective histone deacetylase (HDAC) inhibitor, a potential anticancer agent and also useful for the treatment of other disorders where transcriptional reprogramming might be beneficial. The synthetic route and conditions for each fragment and final product were modified and optimized to make them suitable for larger scale synthesis. With the process we developed, hundreds of grams of each fragment and decagrams of final productlargazole were synthesized in good to excellent yields. The final target largazole was obtained in 21% overall yield over eight steps based on the longest sequence with over 95% HPLC purity.
RESUMEN
VX-950 is a potent, selective, peptidomimetic inhibitor of the hepatitis C virus (HCV) NS3-4A serine protease, and it demonstrated excellent antiviral activity both in genotype 1b HCV replicon cells (50% inhibitory concentration [IC50] = 354 nM) and in human fetal hepatocytes infected with genotype 1a HCV-positive patient sera (IC50 = 280 nM). VX-950 forms a covalent but reversible complex with the genotype 1a HCV NS3-4A protease in a slow-on, slow-off process with a steady-state inhibition constant (K(i)*) of 7 nM. Dissociation of the covalent enzyme-inhibitor complex of VX-950 and genotype 1a HCV protease has a half-life of almost an hour. A >4-log10 reduction in the HCV RNA levels was observed after a 2-week incubation of replicon cells with VX-950, with no rebound of viral RNA observed after withdrawal of the inhibitor. In several animal species, VX-950 exhibits a favorable pharmacokinetic profile with high exposure in the liver. In a recently developed HCV protease mouse model, VX-950 showed excellent inhibition of HCV NS3-4A protease activity in the liver. Therefore, the overall preclinical profile of VX-950 supports its candidacy as a novel oral therapy against hepatitis C.