• Archives of Pharmacal Research
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• v.29 no.6
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• pp.464-468
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• 2006

Novel phenyl branched apiosyl nucleosides were synthesized in this study. The introduction of phenyl group in the 4'-position was accomplished by a [3,3]-sigmatropic rearrangement. Apiosyl sugar moiety was constructed by sequential ozonolysis and reductions. The natural bases (cytosine and adenine) were efficiently coupled with an apiosyl sugar by classical glycosyl condensation procedure (persilyated base and TMSOTf). The antiviral activities of the synthesized compounds were evaluated against the HIV-1, HSV-1, HSV-2 and HCMV.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.25-33
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• 1999

In order to find less toxic antiviral agents from basidiomycetes, EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers.) Karst. EA was examined for antiviral activity against five strains of pathogenic viruses such as encephalomyocarditis virus (EMCV), vesicular stomatitis virus (VSV) Indiana and New Jersey strains, influenza A virus (Flu A), and varicella zoster virus (VZV) in vitro. Antiviral activity was evaluated by plaque reduction assay. Among five strains of viruses tested, EA exhibited the most potent antiviral activity against VSV Indiana strain with 50% effective concentration $(EC_{50})$ of 0.104 mg/ml in Vero cells, and its selectivity index (SI) was 36.5. EA was also examined for the virucidal activity, antiviral activity in preincubation on VSV Indiana strain in order to examine possible mode of antiviral activity. Preincubation of Vero cells with EA did not confer protection against VSV, however, prolonged exposure of cells to EA inhibited the replication of virus dose-dependently. In virucidal activity, the titer of infectious virus did not decrease significantly.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.165.2-165.2
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• 2000

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.559-563
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• 2000

Novel exomethylene cyclopropyl nucleosides were synthesized as potential antiviral agents. The key intermediate 5 was synthesized in 4 steps, from Feists acid 1 and was condensed with purine derivatives by the $S_N2$ type reaction to give some cyclopropyl nucleosides. The synthesized nucleosides did not showed any significant antiviral activity against HSV-1, HSV-2, HCMV, HIV-1, HIV-2, and HBV up to 100 $\mu\textrm{m}$.

• YAKHAK HOEJI
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• v.57 no.1
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• pp.43-54
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• 2013

Viral hepatitis is the inflammation of liver cells caused by viruses, and still one of the major health-care problems worldwide. A number of viruses to cause hepatitis are type A, B, C, D, E or G. Among these viruses leading to hepatitis, B and C are more troublesome being more prone to chronic illness which can cause the potentially fatal conditions of hepatocellular carcinoma (HCC) and/or liver failure. If immediate treatment is not initiated, liver transplant is the only option left. Over the past few decades there has been remarkable progress in diagnose and monitor all hepatitis virus infections for treatment and prevention. Nonetheless, important challenges remain to develop more effective and safe vaccines for prevention as well as antiviral agents to reduce viremia/viral load by inhibiting viral replication. The development and evaluation of antiviral agents through carefully designed clinical trials over the last 25 years has heralded a new dawn in the treatment of patients chronically infected with the hepatitis B and C viruses, but not so for the D virus. The introduction of Direct Acting Antivirals (DDAs) for the treatment of HBV carriers has permitted the long term use of these compounds for the continuous suppression of viral replication. This review aims to summarize the current status and development approaches of antiviral drugs for the treatment of viral hepatitis and future perspectives.

• Journal of Integrative Natural Science
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• v.8 no.1
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• pp.48-55
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• 2015

Novel 2'(${\beta}$)-methyl-5'-deoxyapiose purine phosphonic acid analogues were designed and synthesized from 2-propanone-1,3-diacetate. Condensation successfully proceeded from a glycosyl donor 9 under Vorbr${\ddot{u}}$ggen conditions. Condensation of aldehyde 14 with Wittig reagent [(diethoxyphosphinyl)methylidene] triphenylphosphorane gave the desired nucleoside phosphonate analogues 15. Ammonolysis and hydrolysis of phosphonates gave the nucleoside phosphonic acid analogue 17 and 19. The synthesized nucleoside analogues were subjected to antiviral screening against HIV-1. The adenine analogue 19 exhibited weak in vitro activities against HIV-1.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.221-225
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• 2004

A series of 2',3'-dideoxy-3'-fluoro-D-apiosyl nucleosides 15, 16, 17 and 18 were synthesized enantiomerically with L-Gulonic- ${\gamma}$-lactone as the starting material. The reduction of butenolide 1 with DIBAL-H followed by the Luche procedure afforded the allylic alcohol 2. Ozonolysis and the reduction of compound 4 induced the cyclized lactol, which was acetylated to give the acetate 7. Condensation of the acetate 7 with silylated pyrimidine ($N^4$-benzoyl cytosine) and a purine base (6-chloropurine) under Vorbruggen conditions and deblocking afforded a series of fluorinated apiosyl nucleosides.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.186-190
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• 2002

S- Adenosylhomocysteine hydrolase $(SAH)^1$ catalyzes the hydrolysis of S-adenosylhomocysteine to adenosine and L-homocysteine. Inhibition of this enzyme accumulates S-adenosylhomocysteine, which in turn inhibits S-adenosyl-L-methionine dependent transmethylation, resulting in no formation of the capped methylated structure at the 5'-terminus of viral mRNA. Thus, S-adenosylhomocysteine hydrolase has been an attractive target for the development of broad spectrum of antiviral agents. (omitted)

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.245.3-246
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• 2003

S-Adenosylhomocysteine hydrolase (SAH) catalyzes the hydrolysis of S-adenosylhomocysteine to adenosine and L-homocysteine and has been an attractive target for the development of broad spectrum antiviral agents. Based on the potent inhibitory activity of neplanocin A against SAH, we have reported the synthesis and novel mechanism of action of fluoro-neplanocin A. (omitted)

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3621-3628
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• 2013

Novel 5'-deoxythreosyl purine phosphonic acid analogues containing a 2'-electropositive moiety such as fluorine atom, were designed and synthesized from commercially available 1,3-dihydroxy acetone. Condensation successfully proceeded from a glycosyl donor 6 under Vorbr$\ddot{u}$ggen conditions and cross-metathesis gave the desired phosphonate analogues 7a, 7b, 17a and 17b. The synthesized nucleoside phosphonic acid analogues 13, 16, 23, 26, 28 were subjected to antiviral screening against HIV-1. The bis(SATE) adenine analogue 28 exhibited significant in vitro activities against HIV-1.