• Proceedings of the PSK Conference
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• 2003.04a
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• pp.237.3-238
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• 2003

Carbonucleosides has extensively been studied as a promising anti-viral agents having chemical and metabolical stability. As yet there are no rules relating the structures of carbocyclic nucleosides to their therapeutic activity. although trends among certain kinds of structure have been tentatively put forward. In our research program for discovery of anti-viral drugs, the novel cyclobutyl nucleosides can be expected to be potential antiviral drugs as analogues of cyclobut-A, anti-HBV agent. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.345.2-345.2
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• 2002

Recently. 4'${\alpha}$-C homologated furanose nucleosides. especially alkyl branches. are molecules of considerable current interest. One of reasons for this prominence arises from the notable biological activities as antiviral and antitumor agents. as shown in 4'${\alpha}$-C-methyl-2-deoxythymidine (EC$_{50}$ = 7.2$\mu$M against HIV in MT-4 cell), 4'${\alpha}$-C-fluoromethyl-2-deoxycytidine. 4'${\alpha}$-C-hydroxymethylthymidine and 4'${\alpha}$- -C-azidomethyl-thymidine. (omitted)omitted)

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.180.2-181
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• 2002

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.185.2-186
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• 2002

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.241.1-241.1
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• 2001

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1146-1152
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• 2011

The discovery of 2'-spirocyclopropyl-ribocytidine (J. Med. Chem. 2010, 53, 8150-8160) as a potent inhibitor of RNA synthesis by NS5B ($IC_{50}=7.3{\mu}M$), the RNA polymerase encoded by hepatitis C Virus (HCV), has led to the synthesis and biological evaluation of several carbocyclic versions of 2'-spiropropyl-nucleosides. The cyclopentenol intermediate 7 was successfully constructed via ring-closing metathesis (RCM) from divinyl 6. Spirocyclopropanation of enone 8 was effected by using (2-chloroethyl)-dimethylsulfonium iodide and potassium tert-butoxide to form the desired intermediate 9. The synthesized nucleoside analogues 21-24 were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line. Among them, the cytosine nucleoside analogue 22 exhibited significant anti-HCV activity ($EC_{50}= 8.2{\mu}M$).

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.363.3-364
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• 2002

Unmodified nucleosides exist in either S-type or N-type conformation, but due to the low energy barrier between this two dominating conformers a fast equilibrium between them exists in solution state. Therefore. many approaches to lock the puckering of the furanose ring in N-type or S-type have been made since HIV-1 reverse transciptase is able to discriminate between two conformationally locked carbocyclic AZT triphosphate analogues. (omitted)

• YAKHAK HOEJI
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• v.49 no.1
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• pp.20-24
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• 2005

The synthesis of 4',5'-doubly branched carbocyclic nucleosides was accomplished in this study. The selective methylation in the 5'-position was made by Felkin-Anh controlled Grignard addition. The construction of the required 4'-quaternary carbon was carried out by using a [3,3]-sigmatropic rearrangement. Bis-vinyl 6 was successfully cyclized using a Grubbs' catalyst II. The natural pyrimidine bases (cytosine, uracil, thymine) were efficiently coupled using a Pd(0) catalyst. When the synthesized compounds were examined for their activity against several viruses such as the HIV-1, HSV-1, HSV-2 and HCMV, the cytosine analogue 13 exhibited weak antiviral activity against the HCMV.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.241.1-241.1
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• 2003

Apio nucleosides whose 4'-hydroxymethyl group moves to 3'-position exhibit interesting biological activity such as antitumor or antiviral activity. On the other hand, neplanocin A and aristeromycin are the representative of the carbocyclic nucleosides and have been recognized as potent inhibitors of S-adenosylhomocysteine hydrolase. Based on these findings. it was of great interest to design apio analogues of neplanocin A and aristeromycin. (omitted)

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.105.3-106
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• 2001