• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1277-1320
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• 2002

A novel approach to ${\alpha}-amino-{\delta}-valerolactone$ derivatives 8 by the intramolecular Ugi five-center three-component reaction (U-5C-3CR) using the multifunctional starting material, L-pentahomoserine 5 is described.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.39-42
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• 2012

The use of Smiles rearrangement in Ugi-type couplings with tropolone allows very straightforward multicomponent formation of 2-(N,N-dialkylamino)-2,4,6-cycloheptatrien-1-one derivatives. The Ugi four-component reaction of isocyanides with tropolone (2-hydroxy-2,4,6-cycloheptatrien-1-one), primary amines and aldehydes proceeds smoothly and cleanly under mild conditions to afford 2-(N,N-dialkylamino)-2,4,6-cycloheptatrien-1-one derivatives in fairly good yields.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.3167-3170
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• 2011

• Journal of the Korean Chemical Society
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• v.58 no.2
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• pp.186-192
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• 2014

A series of novel pseudopeptides contained coumarin skeleton were synthesized through the Ugi-four-component reaction. The 3-substituted coumarin-3-carboxamides were formed through reaction of benzaldehyde derivatives, anilines, coumarin-3-carboxylic acid and isocyanides with high yields and high bond-forming efficiency at room temperature. These novel amidated coumarins exhibit brilliant fluorescence in range of 535-547 nm in chloroform.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2004.11a
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• pp.65-70
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• 2004

Modulation of biotransformation enzymes is one mechanism by which a diet high in fruits and vegetable may influence cancer risk. Inhibition of cytochrome P450s (CYP) and concomitant induction of conjugating enzymes are hypothesized to reduce the impact of carcinogens in humans. Thus, exposure to types and amounts of phytochemicals may influence disease risk. Like other xenobiotics, many classes of phytochemicals are rapodly conjugated with glutathione, glucuronide, and sulfate moieties and excreted in urine and bile. In humans, circulating phytochemical levels very widely among individuals even in response to controlled dietary interventions. Polymorphisms in biotransformation enzymes, such as the glutathione S-transferases (GST), UDP-glucuronosyltransferases (UGT), and sulfotransferases (SULT), may ocntribute to the variability in phytochemical clearance and efficacy; polymorphic enzymes with lower enzyme activity prolong the half-lives of phytochmicals in vivo. Isothiocyanates (ITC) in cruciferous vegetables are catalyzed by the four major human GSTs: however reaction velocities of the enzymes differ greatly. In some observational studies of cancer, polymorphisms in the GSTMI and GSTTI genes that result in complete lack of GSTM1-1 protein, respectively, confer greater protection from cruciferous vegetable in individuals with these genotypes. Similarly, we have shown in a controlled dietary trial that levels of GST-alpha-induced by ITC-are higher in GSTMI-null individuals exposed to cruciferous vegetablse. The selectivity of glucuronosyl conjugation of flavonoids is dependent both on flavonoid structure as well as on the UGI isozyme involved in its conjuagtion. The effects of UGI polymorphisms on flavonoid clearnace have not been examind; but polymorphisms affect glucuronidation of several drugs. Given the strong interest in the chemopreventive effects of flavonoids, systematic evaluation of these polymorphic UGTs and flavonoid pharmacokinetics are warranted. Overall, these studies suggest that for phytochemicals that are metabolized by, and affect activity of, biotransformation enzymes, interactions between genetic polymorphisms in the enzymes and intake of the compounds should be considered in studies of cancer risk. Genetic polymorphisms in biotransformation enzymes may account in prat for individual variation in metabolism of a wide range of phytochemicals and their ultimate impact on health.

• Korean Journal of Bronchoesophagology
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• v.9 no.1
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• pp.87-91
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• 2003

Currently gastrointestinal mesenchymal tumors are divided into three major categories: myogenic tumors(leiomyoma, leiomyosarcoma), neurogenic tumors (schwannomas) and neoplasms that belong to neither group, which are known by GIST(gastrointestinal stromal tumors). The stromal tumors are hetrogenous, so that they may show myogenic or neurogenic differentiation or both, or no differentiation at all in some patients. The best defining feature for GIST is their expression of KIT-protein(CD117). Leiomyomas are the most common mesenchymal tumor in esophagus. Esophageal GISTS are very rare in comparision to those of the stomach and intestine. Recently we experieneced one case of the esophageal GIST, so that we describe an esophageal GIST on immunohistochemical analysis. A 70 years old woman complained of dysphagia and nausea for 3 days. FGS showed a huge elevated lesion in lower esophagus 33cm distal to incisor, which was covered with normal mucosa. CT and UGI showed the intramural tumor of lower third of the esophagus. The distal esophagectomy and esophago-gastrostomy were performed. The tumor was located in lower third of esophagus and measured as $6{\times}3.7$cm in size. Immunohistochemically, it showed weakly positive CD117 and diffusely positive S-100. SMA, desmin, NES and chromogranin showed negative immune-reaction. The patient was followed for 15 month after operation. There was no recurrence.