5% methylcellulose and incubated at 37 °C for 4–5 days. Viral foci were counted after crystal violet staining of the plaques. pNL4-3.Luc.R−E− is a lentiviral reporter plasmid containing two frameshift mutations in Env and Vpr-coding regions and a firefly luciferase gene inserted into the nef gene of HIV pNL4-3 clone (obtained through the NIH AIDS Research and Reference Reagent Program, from Dr.

Nathaniel Landau, The Rockefeller University) (Connor et al., 1995 and He et al., 1995). EBOV-G and LASV-G are plasmids expressing EBOV (Zaire strain) and LASV (Josiah strain) glycoprotein, Depsipeptide respectively (kindly provided by Dr. Andrea Cuconati). To determine the effects of compounds on the package of EBOV and LASV G protein pseudotyped lentiviral particles, 3 × 105 of 293T cells seeded in a well of 24-well plates were co-transfected with 0.5 μg EBOV-G or LASV-G expression plasmid, 1 μg of pNL4–3.Luc.R−E− using calcium phosphate precipitation procedure. After 6 h, the cells were replenished with complete DMEM containing concentrations of test compounds. Culture media were harvested at 72 h post transfection and filtered through a 0.45 μm pore sized PES filter. The yields of

pseudotyped viral particles, in presence and absence of compounds, were determined by infection of Huh7.5 cells grown in 96-well plate with 1:1 diluted media from 293T cells. Luciferase activities in cell lysates of Huh7.5 cells were measured (Steady-glo luciferase assay system, Promega) http://www.selleckchem.com/products/erastin.html 72 h post-infection. To determine the cell viability, an MTT based assay (Sigma) was performed. Cells were mock treated or treated with concentrations of test compounds under conditions that were identical to that used for each of the antiviral assays, except that cells were not infected. The dose-dependent curves were generated to determine the inhibitory concentration required to inhibit cell viability by 50% (CC50). A standard in vitro ADME profiling study was performed (Absorption Systems), to determine the aqueous solubility in PBS (pH 4.0 and 7.4) at 300 μM;

plasma protein binding and liver microsome stability in samples of human, rat or mouse origins; inhibition of each of the 5 cytochrome P450 (CYP) isozymes (CYP1A2, 2C9, 2C19, 2D6 and 3A4); and permeability in human epithelial Casein kinase 1 colorectal adenocarcinoma cells Caco-2. ER α-glucosidase I was isolated and purified from rat liver (Karlsson et al., 1993). Oligosaccharide substrate Glc3Man5GlcNAc1 was obtained and labeled as described previously (Alonzi et al., 2008). Varying concentrations of test compounds were added to the mixture of α-glucosidase I and its substrate for 30 min. Following HPLC separation, the amount of hydrolysis product was quantified using peak area analysis. The 50% inhibitory concentrations (IC50) were calculated based on the dose-dependent enzymatic inhibition curves.