- Tamiphosphor monoesters as effective anti-influenza agents
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Oseltamivir is a potent neuraminidase inhibitor for influenza treatment. By replacing the carboxylate group in oseltamivir with phosphonate monoalkyl ester, a series of tamiphosphor derivatives were synthesized and shown to exhibit high inhibitory activities against influenza viruses. Our molecular modeling experiments revealed that influenza virus neuraminidase contains a 371-cavity near the S1-site to accommodate the alkyl substituents of tamiphosphor monoesters to render appreciable hydrophobic interactions for enhanced affinity. Furthermore, guanidino-tamiphosphor (TPG) monoesters are active to the oseltamivir-resistant mutant. TPG monohexyl ester 4e having a more lipophilic alkyl substituent showed better cell permeability and intestinal absorption than the corresponding monoethyl ester 4c, but both compounds showed similar bioavailability. Intranasal administration of TPG monoesters at low dose greatly improved the survival rate of mice infected with lethal dose of H1N1 influenza virus, whereas 4c provided better protection of the infected mice than oseltamivir and other phosphonate congeners by oral administration.
- Chen, Chun-Lin,Lin, Tzu-Chen,Wang, Shi-Yun,Shie, Jiun-Jie,Tsai, Keng-Chang,Cheng, Yih-Shyun E.,Jan, Jia-Tsrong,Lin, Chun-Jung,Fang, Jim-Min,Wong, Chi-Huey
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p. 106 - 118
(2014/06/09)
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- Development of oseltamivir phosphonate congeners as anti-influenza agents
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Oseltamivir phosphonic acid (tamiphosphor, 3a), its monoethyl ester (3c), guanidino-tamiphosphor (4a), and its monoethyl ester (4c) are potent inhibitors of influenza neuraminidases. They inhibit the replication of influenza viruses, including the oseltamivir-resistant H275Y strain, at low nanomolar to picomolar levels, and significantly protect mice from infection with lethal doses of influenza viruses when orally administered with 1 mg/kg or higher doses. These compounds are stable in simulated gastric fluid, liver microsomes, and human blood and are largely free from binding to plasma proteins. Pharmacokinetic properties of these inhibitors are thoroughly studied in dogs, rats, and mice. The absolute oral bioavailability of these compounds was lower than 12%. No conversion of monoester 4c to phosphonic acid 4a was observed in rats after intravenous administration, but partial conversion of 4c was observed with oral administration. Advanced formulation may be investigated to develop these new anti-influenza agents for better therapeutic use.
- Cheng, Ting-Jen R.,Weinheimer, Steven,Tarbet, E. Bart,Jan, Jia-Tsrong,Cheng, Yih-Shyun E.,Shie, Jiun-Jie,Chen, Chun-Lin,Chen, Chih-An,Hsieh, Wei-Che,Huang, Pei-Wei,Lin, Wen-Hao,Wang, Shi-Yun,Fang, Jim-Min,Hu, Oliver Yoa-Pu,Wong, Chi-Huey
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p. 8657 - 8670
(2013/01/15)
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