Search

We recently described the discovery of oxygenated N-alkyl deoxynojirimycin (DNJ) derivative 7 (CM-10-18) with antiviral activity against dengue virus (DENV) infection both in vitro and in vivo. This imino sugar was promising but had an EC(50) against DENV in BHK cells of 6.5 μM, which limited its use in in vivo. Compound 7 presented structural opportunities for activity relationship analysis, which we exploited and report here. These structure-activity relationship studies led to analogues 2h, 2l, 3j, 3l, 3v, and 4b-4c with nanomolar antiviral activity (EC(50) = 0.3-0.5 μM) against DENV infection, while maintaining low cytotoxicity (CC(50) > 500 μM, SI > 1000). In male Sprague-Dawley rats, compound 3l was well tolerated at a dose up to 200 mg/kg and displayed desirable PK profiles, with significantly improved bioavailability (F = 92 ± 4%).

The high levels of hepatitis B virus (HBV) surface antigen (HBsAg)-bearing subviral particles in the serum of chronically infected individuals play an important role in suppressing HBV-specific immune response and are only mildly affected by the current small molecule therapies. Thus, a therapy that specifically reduces HBsAg serum levels could be used in combination therapy with nucleos(t)ide drugs or permit therapeutic vaccination for the treatment of HBV infection. Herein, we report the design, synthesis, and evaluation of novel triazolo-pyrimidine inhibitors (1, 3, and 4) of HBsAg cellular secretion, with activity against drug-resistant HBV variants. Extensive SAR led to substantial improvements in the EC(50) of the parent compound, 5 (HBF-0259), with the best being 3c, with EC(50) = 1.4 ± 0.4 μM, SI ≥ 36. The lead candidates, both 1a (PBHBV-001) and 3c (PBHBV-2-15), were well-tolerated in both normal and HBV-transgenic mice and exhibited acceptable pharmacokinetics and bioavailability in Sprague-Dawley rats., (© 2011 American Chemical Society)