• Bulletin of the Korean Chemical Society
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• 제20권6호
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• pp.631-632
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• 1999

• 대한화학회지
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• 제38권10호
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• pp.774-775
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• 1994

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.115-117
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• 2007

• 대한화학회지
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• 제19권5호
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• pp.367-374
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• 1975

N-X-glycylphenylalanine methyl ester(X-trifluoroacetyl or acetyl)의 글리신잔기를 광 알킬화 반응에 의해 aspartic acid 의 유도체로 전환하였다. 이 반응은 diacetyl/di-t-butyl peroxide(DBP)를 광 개시제로, acetic anhydride를 알킬화제로 하여 350nm 파장의 램프를 사용하므로써 일어난다. DBP와 acetic anhydride에 의한 열반응의 경우에도 같은 알킬화 반응을 관찰하였다. 이 열알킬화 반응은 자유라디칼 반응을 거쳐 일어나기 때문에 이와 비교하여 광 알킬화 반응도 자유라디칼 메카니즘에 의해 일어난 것으로 추측된다.

• Bulletin of the Korean Chemical Society
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• 제23권5호
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• pp.749-757
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• 2002

Chiral oxazolidin-2-one is easily prepared from D-mannitol and demonstrated to undergo highly diastereoselective alkylation reactions via lithium imide Z-enolates of its N-acyl derivatives to afford ${\alpha}-branched$ products. Evans syn and non-Evans sy n aldol products were also selectively obtained using this new auxiliary in high diastereomeric purity by simply changing the stoichiometry of TiCl4 and the nature of the amine base. Also, this new auxiliary is employed in diastereoselective Staudinger-type ${\beta}-lactam$ syntheses. Using 2-chloro-1-methylpyridinium iodide as the dehydrating agent, the reaction of auxiliary tethered acetic acid with trans imines gave the desired ${\beta}-lactams$ with cis-selectivity.

• Bulletin of the Korean Chemical Society
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• 제21권8호
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• pp.767-768
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• 2000

• 대한화학회지
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• 제54권1호
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• pp.174-176
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• 2010

• Archives of Pharmacal Research
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• 제26권12호
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• pp.1047-1054
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• 2003

Molecular chaperones have a crucial role in the folding of nascent polypeptides in endoplasmic reticulum. Some of them are known to be sensitive to the modification by electrophilic metabolites of organic pro-toxicants. In order to identify chaperone proteins sensitive to alkyators, ER extract was subjected to alkylation by 4-acetamido-4 -maleimidyl-stilbene-2,2 -disulfonate (AMS), and subsequent SDS-PAGE analyses. Protein spots, with molecular mass of 160, 100, 57 and 36 kDa, were found to be sensitive to AMS alkylation, and one abundant chaperon protein was identified to be protein disulfide isomerase (PDI) in comparison with the purified PDI. To see the reactivity of PDI with cysteine alkylators, the reduced form ($PDI_{red}$) of PDI was incubated with various alkylators containing Michael acceptor structure for 30 min at $38^{\circ}C$ at pH 6.3, and the remaining activity was determined by the insulin reduction assay. Iodoacetamide or N-ethylmaleimide at 0.1 mM remarkably inactivated $PDI_{red}$ with N-ethylmaleimide being more potent than iodoacetamide. A partial inactivation of $PDI_{oxid}$ was expressed by iodoacetamide, but not N-ethylmaleimide (NEM) at pH 6.3. Of Michael acceptor compounds tested, 1,4-benzoquinone ($IC_{50}, 15 \mu$ M) was the most potent, followed by 4-hydroxy-2-nonenal and 1,4-naphthoquinone. In contrast, 1,2-naphthoquinone, devoid of a remarkable inactivation action, was effective to cause the oxidative conversion of $PDI_{red}$ to $PDI_{oxid}$. Thus, the action of Michael acceptor compounds differed greatly depending on their structure. Based on these, it is proposed that POI, one of chaperone proteins in ER, could be susceptible to endogenous or xenobiotic Michael acceptor compounds in vivo system.

• 공업화학
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• 제7권1호
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• pp.118-128
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• 1996

양이온성 천연 고분자 전해질인 chitosan의 수용성 유도체를 제조하기 위해 chitosan에 먼저 Schiff's base를 형성시키고, 이를 다시 환원시키는 방법으로 chitosan에 N-methyl, N-butyl, N,N-dibutyl기를 각각 도입시킨 후, NMP중에서 methyl iodide를 이용하여 4차 ammonium 기가 도입된 chitosan 유도체를 합성하였다. 이 반응에서 선택적인 N-alkyl 유도체 뿐 아니라 O-alkyl 또한 진행됨을 확인하였다. 제조한 각 4 차 ammonium기가 도입된 chitosan 유도체의 응집성능을 검토하기 위해 제지공장 폐수를 대상으로 응집실험을 행한 결과, chitosan 에서와는 달리 거의 모든 pH 영역에서 일정하게 뛰어난 투과도와 COD 제거율을 보였으며, alkyl 기의 탄소수가 증가할수록 응집능은 증가되었고 그 중에서도 N-butyl dimethyl chitosan ammonium iodide가 가장 우수하였다. 그러나 N-dibutyl methyl chitosan ammonium iodide는 오히려 chitosan 자체보다 감소하는 경향을 나타내었다.

• 약학회지
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• 제45권6호
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• pp.570-574
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• 2001

In order to discover new useful NSAIDs, novel N-substituted 1,2-benzisothiazoline-3-one 1,1- dioxide derivatives, which can exhibit potentially antiinflammatory activity were synthesized. 1,2-Benz-isothiazoline-3-one-N-acetic acids 6a, b were obtained from monochloroacetic acid and sodium 1,2-benz-isothiazoline-3-ones in DMF by N-alkylation reaction. N-Substituted 1,2-benzisothiazoline-3-one 1,1-dioxide derivatives 7a-e were synthesized through the coupling of compound 6a, b and several amines (aniline, 2- aminopyridine , 2-aminothiazole, 2-aminotetrazole) with dicyclohexylcarbodiimide in methyl e no chloride.