• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3417-3422
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• 2012

A new method for the construction of 3-aminoindole nucleosides of 2-acetamido-2-deoxy-D-glucose based is presented. Nitration and acetylation of the indole nucleosides by acetic anhydride-nitric acid mixture followed by reduction using silver catalyst (SNSM) impregnated on silica gel, afforded the corresponding amino indole nucleosides. The nucleosides were tested for antiviral activity against hepatitis B virus (HBV) to show different degrees of antiviral activities or inhibitory actions.

• YAKHAK HOEJI
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• v.35 no.6
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• pp.530-554
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• 1991

The synthetic methodologies for the preparation of C-nucleosides are divided into four categories, and each category is discussed in details. The chemical rections which lead to other C-nucleosides from preformed the natural product pseudouridine are described first, followed by synthesis of C-nucleosides by condensation of pre-formed heterocyclic base with sugar, and by construction of heterocyclic base from a carbohydrate intermediate that bear functional carbon fragment at the anomeric position. Finally, methods of total synthesis of C-nucleosides from carbohydrate and achiral starting materials are presented.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.346.2-346.2
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• 2002

Recently, several branched-nucleosides have been synthesized and evaluated as potent antitumor or antiviral agents. Among them, 4'${\alpha}$--C-ethenyl and 4'${\alpha}$-C-ethynyl nucleosides which having an additional double or triple bond at 4'-position were reported to be as potent antiviral and anlitumor activities. Encouraged by these interesting structures and antiviral activities, it was determined to synthesize novel classes of nucleosides comprising branched carbocyclic nucleosides with an additional aryl group at 4'${\alpha}$-position using versatile reiterative three-step sequences from simple acyclic precursor '2-hydroxyacetophenone. Our efforts toward the synthesis of novel nucleosides analogues are reported herein.

• Journal of Nutrition and Health
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• v.31 no.4
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• pp.679-686
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• 1998

This study was performed to determine whether the infusion of nucleosides and a nucleotide mixture directly ito intestinal lumen can induce a regenerative effect on impaired intestinal mucosa. The effects of massive small bowel resention and also total parenteral nutrition were induced by surgical creation of Thirty-Vella fistual in male Sprague-Dawley rats. The rats received saline solution (Control group) or nucleosides and a nucleotide mixture(lower concentration group(Nucl) or higher concentration group (Nuc2) every two days into the fistula. Mucosal protein, DNA , ornithine decarboxylase(ODC) activity, and morphometry were evaluated at 9 or 21 days postoperation in the fistual and also in the residual ileal segment. On the 9th day, mucosal protein, DNA content, and villous surface area in the fistula and also in the residual ileum increased in rats that received nucleosides and a nucleotide mixture of lower concentration (Nuc 1). On the 21 th day, there were no significant differences in intestinal mucosa between the control group and the lower level nucleoside nucleotide mixture-treated group. The fistula villous height of the higher nucleosides and a nucleotide mixture group was higher than in the control rats. Fistula mucosal ODC activities were not significantly different between groups although the mucosal ODC activity of the residual ileal segment was increased on the 9th day. Our data suggests that this animal model is suitable for studying the effect of dietary factors on intestinal mucosal growth and regeneration after villous stropy , differentiating direct effects of diet on the intestine from systemic effects. It is also suggested that external nucleosides and nucleotides have supportive effects on intestinal mucosal regeneration.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2318-2328
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• 2009

Massive deadenylation of adenine based-nucleosides induced by halogenated alkanes at the physiological condition have been observed. For the study of deadenylation effects by the different substituents and/or functionality in halogenated alkanes, diverse kinds of halogenated alkanes were incubated with adenine based-nucleosides (ddA, dA and adenosine) for 48 h at the physiological condition (pH 7.4, $37\;{^{\circ}C}$), which were analyzed by HPLC and further confirmed by LC-MS. Among the sixteen different halogenated alkanes, we observed massive deadenylation of nucleosides by 2-bromo-2-methylpropane, 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane. The order of deadenylation rate was highest in 2-bromo-2-methylpropane followed by 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane. In addition, time and dose response relationship of deadenylation in adenine based-nucleosides induced by 2-bromo-2-methylpropane, 2,3-dibromopropene, 2-bromopropane, bromoethane and 2-iodopropane at the physiological condition were investigated. In addition, deadenylation of calf thymus DNA induced by halogenated alkanes was also investigated. These results suggest that the toxic effect of certain halogenated alkanes might be from the depurination of nucleosides.

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.887-891
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• 2003

Novel trans-2,2-dimethylcyclopropyl nucleosides were synthesized as potential antiviral agents. The key intermediate, 3, was synthesized via five steps from ethyl chrysanthemate and condensed with purine bases using the Mitsunobu reaction to give six cyclopropyl nucleosides. These synthesized nucleosides did not show any significant antiviral activity against HSV-1, HSV-2, EMCV, Cox B3, or VSV, at concentrations up to 100 $\mu M$.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.271-275
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• 2003

Easy and efficient synthetic route of novel 4'-C methyl branched carbocyclic nucleosides is described. The installation of alkyl and aryl groups at 4'-position of carbocyclic nucleosides were successfully made via sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) starting from simple ketones such as acetol. Adenine and uracil were coupled via Pd(0) catalyzed reaction, followed by desilylation to give novel compounds 13 and 14, respectively.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.679-685
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• 2003

A series of novel cyclopropyl nucleosides was synthesized using the highly stereoselective Simmons-Smith reaction starting from 1,2:5,6-di-Ο-isopropylidene-D-mannitol. The structural assignments of these nucleosides were determined by NMR studies and X-ray crystallography. All the synthesized nucleosides were assayed against several viruses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.130-136
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• 1997

Total parenteral nutritional effect was induced by surgical creation of Thiry-Vella fistula(TVFs) in rats. Glutamine, glycine or nucleosides/nucleotide mixture in solution was injected into the loops for 2, 4, 6, 8 days. Control animals received a 0.9％ saline solution. Results include weight gain, total protein, DNA, ［$^3$H］ thymidine incorporation into DNA, morphometry of the intestine in both TVFs and intestine in continuity. Perfusion of nucleosides/nucleotide mixture into the bypassed loops caused an increase in total protein, DNA content, villous height, villous surface area in loops. The injection of glycine into loops caused an increase in ［$^3$H］ thymidine incorporation but the mean values of the protein and DNA contents were not significantly different from those in group Cont and group Nuc. Overall values for group Gln were slightly higher than those of the control but the differences were not statistically significant. This study suggests that this animal model may be useful for studying the effect of dietary factors on intestinal growth and maturation, separating the direct effect of diet from systemic effect on the intestine.

• Archives of Pharmacal Research
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• v.6 no.1
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• pp.79-81
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• 1983

Several potent anti-herpes virus nucleosides, 2'fluoro-2'-deoxyarabinofuranosyl pyrimidine nucleosides, were prepared in good yields by a new condensation method using sodium iodide and a new solvent system, and FMAU could be also prepared directly from thymine by this method.