• Bulletin of the Korean Chemical Society
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• 제12권3호
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• pp.257-259
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• 1991

• Journal of Pharmaceutical Investigation
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• 제40권6호
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• pp.367-372
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• 2010

Rabeprazole sodium (RPN) is known to be very unstable at acidic condition or some acidic pharmaceutical excipients such as acrylic acid polymer (carbomer 934) with carboxylic acids. Thus, degradation mechanism of binary blends of rabeprazole with pharmaceutical excipients in a solid state without using solvents at three different ratios (3:1, 1:1 and 1:3) was investigated using Fourier transform infrad (FTIR) spectroscopy. Alkalizer (MgO), neutral hydroxypropymethylcellulose (HPMC 4000) were also tested for comparison. The binary blends were stored under accelerated conditions ($40^{\circ}C$/75% relative humidity) for two weeks. The concentration of thioether rabeprazole from the binary blends with acidic carbomer 934 increased as the rabeprazole concentration decreased. In addition, the degradation half-life of rabeprazole as well as the relative peak area ratios obtained from FTIR spectra of S=O stretching at $1094.1\;cm^{-1}$ decreased consistently as the fraction of carbomer 934 increased due to its sensitivity between the basic benzimidazole nitrogen and carboxylic acid group of carbomer 934. The physical appearance also turned into strong brown color in the presence of carbomer 934. In contrast, there were no significant changes in the degradation kinetics of rabeprazole with MgO and HPMC 4000 in a solid state. This present study demonstrated that the solid-state compatibility test with the aid of HPLC chromatographic and FTIR spectral analyses could offer a valuable methodology to select suitable pharmaceutical excipients and to elucidate the degradation mechanism of RPN for drug formulations at the early formulation stages.

• Bulletin of the Korean Chemical Society
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• 제27권8호
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• pp.1099-1114
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• 2006

Our studies in the area of single electron transfer (SET) photochemistry have led to the discovery of efficient processes, in which regioselective formation of carbon-centered radicals takes place by nucleophile assisted desilylation of $\alpha$-trialkylsilyl substituted ether, thioether, amine and amide centered cation radicals. The rates of bimolecular desilylation of the intermediate cation radicals exceed those of other cation radical $\alpha$-fragmentation processes (e.g.,-deprotonation). This sereves as the basis for the design of highly regioselective, SET-induced photomacrocyclization reactions of polyether, polythioether, polyamide, and polypeptide linked phthalimides. Photocyclization reactions of trimethylsilyl-terminated substrates in these families are unique in that they produce polyfunctionalized macrocyclic substances in a highly efficient and regioselective manner. In addition, our studies in this area have led to important information about the factors that govern chemical and quantum efficiencies that should be applicable to a wide variety of redox processes promoted by SET from substrates containing more than one electron donor site.

• Macromolecular Research
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• 제16권1호
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• pp.36-44
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• 2008

A series of polysiloxanes containing alkylsulfonyl side groups were synthesized using a polymer analogous reaction beginning from poly(methylhydrosiloxane) and the corresponding olefins. These polymers showed a mesomorphic behavior with smectic liquid crystalline phases. The chemical and physical properties of these polymers were examined using nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry, optical polarizing microscopy, and X-ray diffraction.

• Current Research on Agriculture and Life Sciences
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• 제5권
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• pp.168-172
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• 1987

광학성체인 isopropylidene glycerols로 부터 mercaptogiycerol을 합성하였다. 1,2-Isopropylideneglycerol을 tosyl화 하고 다시 tosyl group을 thiolacetate로 치환하였다. 염기성 가수분해와 산화에 의해 1,1'-dithiobis-2,3-isopropylidene-2,3-propanediol이 생성되었다. 이 화합물을 mercaptogiycerol 합성을 위해 사용함으로써 1-decenyl lithium으로 cis-S-dec-1'-enyl-2,3-isopropylidene-1-mercapto-2,3-propanediol을 생성하였다. 본 생성물은 plasmalogenase용 thioplasmaloger 기질 조제에 사용된다.

• Biomolecules & Therapeutics
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• 제1권2호
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• pp.160-165
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• 1993

The effects of Glycyrrhizae Radix (GR) on the metabolism of acetaminophen (AA) were examined in male Sprague-Dawley rats. The methanol extract of GR (500 mg/kg) was administered orally to rats for 6 days. AA and its metabolites excreted in bile, urine and blood within 120 min after dosing of AA (150 mg/kg, i.v.) were assayed by HPLC. Treatment of rats with the methanol extract of GR significantly increased the cumulative biliary excretion of AA-glucuronide (156% of the control) and decreased that of AA-sulfate (63% of the control). The cumulative urinary excretion of AA-glucuronide was also significantly increased to 132% of the control. GR treatment significantly increased total (biliary plus urinary) excretion of AA-glucuronide (172% of the control) without influencing thioether and sulfate conjugates of AA. The results clearly show that GR enhances UDP-glucuronosyl transferase-mediated detoxication of AA, but may not influence sulfotrans-ferase-mediated and cytochrome P-450-mediated metabolites formation.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.801-806
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• 2002

Cyclicpeptides are important targets in peptide synthesis because of their interesting biological properties. Constraining highly flexible linear peptides by cyclization is one of the mostly widely used approaches to define the bioactive conformation of peptides. Cyclic peptides often have increased receptor affinity and metabolic stability over their linear counterparts. We carried out virtual screening experiment via docking in order to understand the interaction between HLE-Human Leukocyte Elastase and ligand peptide and to identify the sequence that can be a target in various ligand peptides. We made cyclic peptides as a target base on Metlle-Phe sequence having affinity for ligand and receptor active site docking. There are three ways to cyclize certain sequences of amino acids such as Met-lie-Phe-Gly-Ile. First is head-to-tail cyclization method, linking between N-terminal and C-terminal. Second method utilizes amino acid side chain such as thiol functional group in Cys, making a thioether bond. The last one includes an application of resin-substituted amino acids in solid phase reaction. Among the three methods, solid phase reaction showed the greatest yield. Macrocyclization of Fmoc-Met-Ile-Phe-Gly-Ile-OBn after cleavage of Fmoc protection in solution phase was carried out to give macrocyclic compound 5 in about 7% yield. In the contrast with solution phase reaction, solid phase reaction for macrocyclization of Met-Ile-Phe-Gly-Ile-Asp-Tentagel in normal concentrated condition gave macrocyclic compound 7 in more than 35% yield.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.199-199
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• 1994

Thioglycerol과 glycerol로부터 rac-1-S-octa-decyl-2-O-palmitoyl-1-S-thioglycerol-3-phosphate (DL -PTBA-P)와 rac-1-O-octadecyl-2-O-palmitoyl-g1ycerol-3-phosphate (DL-PBA-P)등을 합성하였고, 이들에 ara-C 유도체인 ara-CMP morpholidate를 반응시켜 최종 산물인 ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara-CDP-DL-PTCA 및 ara-CDP-DL-PTBA등을 합성하였다. 이들 최종산믈의 항암효과는 L1210 lymphoid leukemia, colon 26 carcioma, M5076 sarcoma, C-1300 neuroblastoma, 3-Lewis lung carcinoma, WEHI-3B leukemia, human colon cancer, hum an pancreatic cancer 등의 암세포주를 사용하여 실험하였다. L1210를 DB/2J의 뇌막 또는 복강, DBA/1J의 복강내에 이식하여 ara-C, Ehss thioether lipid의 ara-C 유도체 (ara-CDP-L-DP, ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara -CDP-DL-PTCA, ara-CDP-D-PTBA, ara-CDP-L-PTBA, ara-CDP-DL-PTBA)를 단일 투여 또는 중복 투여하였고, 3-Lewis는 C57BL/6 의 발바닥 피하, colon26은 BALB/C의 견갑상부 히아조직, M5076은 C57BL/6의 피하, WEHI-3B는 BALB/C의 복강, C-1300는 A/strong Ros에 각각 이식한 후 ara-C 또는 ara-CDP-DL-PTBA를 단일 또는 중복 투여하였다.