5 research outputs found

    A SEARCH FOR RETROVIRUS INFECTION IN SYSTEMIC LUPUS-ERYTHEMATOSUS AND RHEUMATOID-ARTHRITIS

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    Evidence for retroviral infection in general and human immunodeficiency virus (HIV) infection in particular was sought in freshly isolated peripheral blood T cells, B cells, and monocyte-macrophages from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) and also in T cell and B cell lines established from the same source. Similar cells isolated from rheumatoid synovial membrane were also examined. The strategy used for the detection of virus was cocultivation with susceptible cell lines looking for syncytia formation, reverse transcriptase production, and nucleic acid hybridisation with HIV cDNA probes. No evidence for infection was obtained

    The discovery of potent nonstructural protein 5A (NS5A) inhibitors with a unique resistance profile-Part 1

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    Nonstructural protein 5A (NS5A) represents a novel target for the treatment of hepatitis C virus (HCV). Daclatasvir, recently reported by Bristol–Myers–Squibb, is a potent NS5A inhibitor currently under investigation in phase 3 clinical trials. While the performance of daclatasvir has been impressive, the emergence of resistance could prove problematic and as such, improved analogues are being sought. By varying the biphenyl‐imidazole unit of daclatasvir, novel inhibitors of HCV NS5A were identified with an improved resistance profile against mutant strains of the virus while retaining the picomolar potency of daclatasvir. One compound in particular, methyl ((S)‐1‐((S)‐2‐(4‐(4‐(6‐(2‐((S)‐1‐((methoxycarbonyl)‐L‐valyl)pyrrolidin‐2‐yl)‐1H‐imidazol‐5‐yl)quinoxalin‐2‐yl)phenyl)‐1H‐imidazol‐2‐yl)pyrrolidin‐1‐yl)‐3‐methyl‐1‐oxobutan‐2‐yl)carbamate (17), exhibited very promising activity and showed good absorption and a long predicted human pharmacokinetic half‐life. This compound represents a promising lead that warrants further evaluation

    The discovery of potent nonstructural protein 5A (NS5A) inhibitors with a unique resistance profile—part 2

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    In ongoing studies towards novel hepatitis C virus (HCV) therapeutics, inhibitors of nonstructural protein 5A (NS5A) were evaluated. Specifically, starting from previously reported lead compounds, peripheral substitution patterns of a series of biaryl‐linked pyrrolidine NS5A replication complex inhibitors were probed and structure–activity relationships were elucidated. Using molecular modelling and a supercritical fluid chromatographic (SFC) technique, intramolecular H‐bonding and peripheral functional group topology were evaluated as key determinants of activity and membrane permeability. The novel compounds exhibited retained potency as compared with the lead compounds, and also showed promising results against a panel of resistance viruses. Together, the results of the study take us a step closer towards understanding the potency of daclatasvir, a clinical candidate upon which the compounds were based, and to designing improved analogues as second‐generation antiviral agents targeting NS5A
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