Regardless of the route of transmission, R5-tropic HIV-1 predominates early in infection, rendering C-C chemokine receptor type 5 (CCR5) antagonists as attractive agents not only for antiretroviral therapy but also for prevention. Here, we report the specificity, potency, and underlying mechanism of action of a novel small molecule CCR5 antagonist, TD-0680. TD-0680 displayed the greatest potency against a diverse group of R5-tropic HIV-1 and SIV strains when compared with its prodrug, TD-0232, the Food and Drug Administration-approved CCR5 antagonist Maraviroc, and TAK-779, with EC50 values in the subnanomolar range (0.09-2.29 nM). Importantly, TD-0680 was equally potent at blocking envelope-mediated cell-cell fusion and cell-mediated viral transmission as well as the replication of a TAK-779/Maraviroc-resistant HIV-1 variant. Interestingly, TD-0232 and TD-0680 functioned differently despite binding to a similar transmembrane pocket of CCR5. Site-directed mutagenesis, drug combination, and antibody blocking assays identified a novel mechanism of action of TD-0680. In addition to binding to the transmembrane pocket, the unique exo configuration of this molecule protrudes and sterically blocks access to the extracellular loop 2 (ECL2) region of CCR5, thereby interrupting the interaction between virus and its co-receptor more effectively. This mechanism of action was supported by the observations of similar TD-0680 potency against CD4-dependent and -independent SIV strains and by molecular docking analysis using a CCR5 model. TD-0680, therefore, merits development as an anti-HIV-1 agent for therapeutic purposes and/or as a topical microbicide for the prevention of sexual transmission of R5-tropic HIV-1.

Modification of 1,3,3,4-tetra-substituted pyrrolidine embodied CCR5 receptor antagonists revealed that introducing a fluoro group at the 3-position of the 3-phenyl group to reduce metabolism did not adversely affect the high potency against HIV infection, and that replacing the piperidine ring with a tropane ring could deliver the most potent anti-HIV agents. Stereochemistry of the substituted tropane ring is essential for maintaining the potent anti-HIV activity because only exo-isomers displayed subnanomolar whole cell activity.

By using functionality inversion approach, we identified a new scaffold containing (S)-alpha-phenyl-gamma-amino butanamide as CCR5 antagonists derived from the 1,3-propanediamine carboxamide pharmacophore protocol. The (2S)-2-phenyl-4-(8-aza-bicyclo[3.2.1]octan-8-yl)-butanamide derivatives display significantly high potency to antagonize CCR5 receptor with nanomolar IC50 values. (C) 2010 Elsevier Ltd. All rights reserved.

A novel series of CCR5 antagonists has been identified, utilizing the lead, nifeviroc, which were further modified based on bioisosteric principles. Lead optimization was pursued by balancing potential toxicity and potency. Potent analogues with low toxic properties were successfully developed by formation of urea and amide bonds at the nitrogen at position 4- of the pyrrolidine ring.

By employing pharmacophore-based design and the privileged fragments reassembly, a series of piperidine-/tropane-/piperazine-bridged CCR5 antagonists were designed and synthesized via an efficient convergent synthesis strategy, with focus on the optimal choice of the basic center carrier structure. Significantly, the 4-amino-4-methylpiperidine bridged 1-acyl-1,3-propanediamine compounds were identified as a new class of nanomolar CCR5 antagonists, providing an efficient approach and novel scaffolds for further development of potent CCR5 inhibitors.

Chemokine receptors belong to a superfamily of proteins that signal through coupled heterotrimeric G proteins. Chemokine receptor CCR5 is the major co-receptor essential for HIV entry into host cells, and now chemokine CCR5 receptor has become an important target in searching for anti-HIV drugs. Here, we describe the establishment of a human embryonic kidney (HEK) 293/CCR5-HA cell line stably expressing CCR5 receptor with influenza hemagglutinin (HA) tag at the N termini on the membrane surface of HEK293 cells. Plasmid pcDNA3.0-CCR5-HA was transfected into HEK293 cells, and monoclonal HEK293 cell lines expressing CCR5 receptor were generated under G418 selection. The expression of functional CCR5 receptor was tested by GTP?S assay, and the results showed about 5 monoclonal HEK293 cell lines expressed functional CCR5 receptor, and of which No.7 monoclonal cell line is the best. The FACS analysis results further confirmed that CCR5 receptor was positive in 96.89% of No.7 monoclonal HEK293/CCR5-HA cell line. Further results showed that RANTES significantly stimulated GTP?S binding in the dose-dependent manner, and CCR5 antagonist Sch-351125 inhibited RANTES stimulated GTP?S binding in the dose-dependent manner in No.7 monoclonal HEK293/CCR5-HA cell line. Our results suggest that the established HEK293/CCR5-HA cell line is suitable for highthroughput screening and is feasible to identify CCR5 receptor antagonists.

Cdc7 kinase plays a critical role in the regulation of DNA replication in eukaryotic cells and has been proposed as a target for cancer therapy. We have identified a class of Cdc7/Dbf4 inhibitors with a pyrido-thieno-pyrimidine core structure. Synthesis of a focused pyrido-thieno-pyrimidine library yielded potent and selective Cdc7 inhibitors with antiproliferative activity against cancer cells in vitro. Their synthesis and SAR data are presented herein.

Objective:To observe the clinical effect of Xiaofeng Huoxue and Runfei Liqi method for treating cough variant asthma (CVA). Methods:82 cases of CVA were divided into the treatment group (42 cases) and the contrast group (40 cases) randomly. The treatment group was treated by the self-made decoction with function of xiaofeng huoxue and runfei liqi. The contrast group was treated by budesonide powder for inhalation and procaterol hydrochloride tablets. The clinical symptoms, eosinophil cell ounting of induced sputum, serum total IgE level and the peak expiratory flow rate (PEFR%) were observed. Results:The total effective rate of the treatment group and the contrast group was 92.85% and 78.94% respectively. The clinical symptom improvement of the treatment group was superior to that of the contrast group. The difference had a statistic meaning (P0.05). The eosinophil cell ounting of induced sputum and PEFR% of two groups was decreased with no significant difference (P0.05). The serum total IgE level of the treatment group was much reduced than that of the contrast group (P0.05). Conclusion:Xiaofeng Huoxue and Runfei Liqi method is effective on treating CVA by quick controling the clinical symptoms, improving the metamorphic reaction and tracheal inflammation.

Piperazinopiperidine amide analogs are among the most promising CCR5 antagonists. As an effective extension of a previously-reported methodology to synthesize such compounds, forward- and reverse-syntheses were successfully developed in which the convergent synthesis of the piperazinopiperidine nucleus, with a building block of 4-substituent-4-aminopiperidine, served as a common key step. The two-way approach affords a comprehensive access to the piperazinopiperidine templated library with variation on the pharmacophore sites. Thus, a SAR study of our synthesized piperazinopiperidine-based CCR5 antagonists was conducted with respect to the structure and configuration of the substituent on the piperazine ring. The S-configuration of the benzylic-substituent is vital for the CCR5 binding, and the bulky or aryl substituent on the 2-position in the piperazine ring is detrimental to the activity. By using the forward-synthesis approach, the best compound in the chiral piperazine-based CCR5 antagonist series, Sch-D (Vicriviroc), was conveniently synthesized in an excellent yield.

A novel series of quinolinyl-methylene-thiazolinones has been identified as potent and selective cyclin-dependent kinase 1 (CDK1) inhibitors. Their synthesis and structure activity relationships (SAR) are described. Representative compounds from this class reversibly inhibit CDK1 activity in vitro, and block cell cycle progression in human tumor cell lines, suggesting a potential use as antitumor agents.

CDK1 is a nonredundant cyclin-dependent kinase (CDK) with an essential role in mitosis, but its multiple functions still are poorly understood at a molecular level. Here we identify a selective small-molecule inhibitor of CDK1 that reversibly arrests human cells at the G(2)/M border of the cell cycle and allows for effective cell synchronization in early mitosis. Inhibition of CDK1 during cell division revealed that its activity is necessary and sufficient for maintaining the mitotic state of the cells, preventing replication origin licensing and premature cytokinesis. Although CDK1 inhibition for up to 24 h is well tolerated, longer exposure to the inhibitor induces apoptosis in tumor cells, suggesting that selective CDK1 inhibitors may have utility in cancer therapy.