[Study on chemical bibenzyls in Dendrobium gratiosissimum].

Nineteen compounds were isolated and structurally characterized from an ethanol extract of Dendrobium gratiossimum, including dendrogratiol A(1), DDB-1(2), 3,4-dihydroxyl-5,3',4'-trimethoxybibenzyl(3), amoenylin(4), chrysotoxine(5), DTB(6), 3,4,4'-trihydroxyl-5,3'-dimethoxybenzyl(7), 3-methylgiga(8), aloifol(9), gigantol tetramethyl ether(10), batatasin Ⅲ(11), moscatilin(12), moniliformine(13), gigantol(14), DMB(15), flavanthrinin(16), cannithrene-2(17), 3,4-dihydroxyl-5,4'-dimethoxystilbene(18) and 4-hydroxy-3,5,4'-trimethoxystilbene(19). 1 was a new compound, and 2-10, 16, 18 and 19 were obtained from this plant species for the first time. In vitro cytotoxic and antiviral activities of these isolates were evaluated, which displayed that 4 showed moderate cytotoxicity against human hepatoma cell line HepG2 with the IC_(50) of 10.15 µmol·L~(-1); 7 and 12 exhibited moderate inhibitory activity towards HIV virus with the IC_(50) of 9.35 and 9.15 µmol·L~(-1), respectively; and 10 displayed inhibitory activity against IAV virus with the IC_(50) of 8.90 µmol·L~(-1).

Development and Application of An Assay for High-throughput Antiviral Compounds Screening against Alphaviruses / 病毒学报

To establish a cell-based rapid luciferase suppression assay for high-throughput screening (HTS) anti-alphaviruses compounds screening, which could cause viral encephalitis, raise the social issues associated directly with public health and huge economic burden to the society. The Gaussia luciferase assay system was used for HTS model for identifying inhibitors of labeled virus XJ160-GLUC. The decreased 50% GLUC activity inhibition ratio was deemed to be the screening positive index. The reaction system in this model was optimized, and the reliability of the model was evaluated. For HTS model's optimization, cells were infected with XJ160-GLUC at an MOI of 0.025 PFU/cell. The supernatant treated with compounds 48h were collected for GLUC expression detection. In the model, Z' factor was up to 0.71, demonstrating that HTS assay for identifying inhibitors that target all aspects of the viral life cycle of XJ160-GLUC was stable and reliable. After screening 8080 compounds (five-in-one), 341 positive samples were selected, and the positive rate was 4.2% with a cutoff at 50% inhibition. Then 1705 compounds were screened subsequently and the positive rate was 1.1% with obtaining 19 positive compounds. These results will lay the foundation for finding the anti-alphaviruses' drug targets.

Establishment of drug screening assay and pharmacodynamic evaluation method targeting influenza RNA polymerase / 药学学报

Influenza virus RNA-dependent RNA polymerase (RdRP) is essential for replication and expression of influenza virus genome. Viral genomic sequences encoding RdRP are highly conservative, thus making it a potential anti-influenza drug target. A cell-based influenza RdRP inhibitor screening assay was established by a luciferase reporter system to analyze the activity of RdRP. Specificity study and statistic analysis showed that the screening assay is sensitive and reproducible.