Ruifang Pang

Design, synthesis, and biological evaluation of novel quinoline derivatives as HIV-1 Tat-TAR interaction inhibitors.

Thirty-two quinoline derivatives were designed and synthesized as HIV-1 Tat-TAR interaction inhibitors. All the compounds showed high antiviral activities in inhibiting the formation of SIV-induced syncytium in CEM174 cells. Nine of them with low cytotoxicities were evaluated by Tat dependent HIV-1 LTR-driven CAT gene expression colorimetric enzyme assay in human 293T cells, indicating effective inhibitory activities of blocking the Tat-TAR interaction. Molecular modeling experiments indicated that these compounds may inhibit Tat-TAR interaction by binding to Tat protein instead of TAR RNA.

Discovery of dual inhibitors targeting both HIV-1 capsid and human cyclophilin A to inhibit the assembly and uncoating of the viral capsid

HIV-1 assembly and disassembly (uncoating) processes are critical for the HIV-1 replication. HIV-1 capsid (CA) and human cyclophilin A (CypA) play essential roles in these processes. We designed and synthesized a series of thiourea compounds as HIV-1 assembly and disassembly dual inhibitors targeting both HIV-1 CA protein and human CypA. The SIV-induced syncytium antiviral evaluation indicated that all of the inhibitors displayed antiviral activities in SIV-infected CEM cells at the concentration of 0.6-15.8 microM for 50% of maximum effective rate. Their abilities to bind CA and CypA were determined by ultraviolet spectroscopic analysis, fluorescence binding affinity and PPIase inhibition assay. Assembly studies in vitro demonstrated that the compounds could potently disrupt CA assembly with a dose-dependent manner. All of these molecules could bind CypA with binding affinities (Kd values) of 51.0-512.8 microM. Fifteen of the CypA binding compounds showed potent PPIase inhibitory activities (IC(50) values<1 microM) while they could not bind either to HIV-1 Protease or to HIV-1 Integrase in the enzyme assays. These results suggested that 15 compounds could block HIV-1 replication by inhibiting the PPIase activity of CypA to interfere with capsid disassembly and disrupting CA assembly.

Design and SAR of new substituted purines bearing aryl groups at N9 position as HIV-1 Tat–TAR interaction inhibitors

Twenty-four purine derivatives bearing aryl groups at N9 position were designed and synthesized as HIV-1 Tat-TAR interaction inhibitors. All the compounds showed high antiviral activities in inhibiting the formation of SIV-induced syncytium in CEM174 cells. Ten of them with low cytotoxicities were evaluated by Tat dependent HIV-1 LTR-driven CAT gene expression colorimetric enzyme assay in human 293T cells at a concentration of 30 microM, indicating effective inhibitory activities of blocking the Tat-TAR interaction. The aryl groups at N9 position affected the binding affinities between compounds and TAR RNA, showing some specificities of aryl groups to TAR RNA.

Design, synthesis, and biological evaluation of novel substituted [1,2,3]triazolo[4,5‑ d ]pyrimidines as HIV-1 Tat-TAR interaction inhibitors

A novel series of compounds, derived from [1,2,3]triazolo[4,5-d]pyrimidines with a guanidyl group or amino group-terminated side chain was designed and synthesized as HIV-1 trans-activator of transcription–trans-activation responsive region (Tat–TAR) interaction inhibitors. Their ability to inhibit Tat–TAR RNA interaction was determined by a Tat-dependent HIV-1 long terminal repeat (LTR)-driven chloramphenicol acetyltransferase (CAT) assay and simian immunodeficiency virus (SIV)-induced syncytium evaluation. The binding of the compounds with TAR RNA was conducted by molecular modeling and capillary electrophoresis (CE) analysis. The results showed that all the compounds could block the Tat–TAR interaction and have antiviral activities.