• Bulletin of the Korean Chemical Society
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• 제23권10호
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• pp.1375-1376
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• 2002

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.365-366
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• 2002

• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1729-1732
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• 2004

• Archives of Pharmacal Research
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• 제17권5호
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• pp.327-330
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• 1994

Bromolactonization of 2-substituted-1-cyclohexenyl-1-acetic acids with 1, 3-dibromo-5, 5-dime-thylhydantoin 9DBH) and potsssium tertiary butoxide (t-BuOK0 in anhydrous DMF was found to proceed in a highly regioselective manner. The reaction predominantly resulted in the formation of ${\betha}-lactones$ (greater than 96%).

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.136-138
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• 2004

• Applied Biological Chemistry
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• 제38권5호
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• pp.473-477
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• 1995

Hymenoxys brachyactis지상부의 디클로로메탄 추출액으로부터 3개의 sesquiterpene lactone들과 새로운 lactone화합물인 isohymenograndin을 확인하였다. 그리고 2개의 sesquiterpene lactone축합물인 biennine C와 독성이 있는 것으로 알려진 flavone화합물인 hispidulin을 분리하여 각각을 고자장 NMR, Mass등의 기기를 이용하여 구조결정 하였다. Biennine C는 gas chromatography와 Mass분석을 통하여 독성화합물 hymenoxon과 화합물 8과의 Diels-Alder축합물임을 확인하였다. biennine C를 포함한 이상의 lactone화합물들은 ${\alpha},{\beta}$-unsaturated lactone으로서 독성화합물군으로서 알려진 hymenovin과 공통적인 구조를 갖고 있어서 생체독성을 나타낼 가능성이 높은 화합물들로 사료된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.322-328
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• 2005

Acylhomoserine lactones (AHLs) are known to be the triggering molecules in the quorum sensing mechanism of many gram-negative bacteria. In order to detect AHL inhibitors that are potential biofilm inhibitors, a convenient and sensitive bioassay was developed based on the $\beta$-galactosidase activity ($\beta$-GAL) of a recombinant Agrobacterium tumefaciens strain. A series of commercially available AHLs were tested for inducing $\beta$-GAL at varying concentrations in agar-plate and liquid cultures of the reporter strain. All AHLs tested exhibited a concentration­dependent induction, and octanoyl homoserine lactone (OHL) showed the highest sensitivity with a detection limit of 0.1 nM in the liquid culture assay. When fimbrolide, a known quorum sensing inhibitor, was added, induction of $\beta$-GAL by OHL was repressed. The repression at a constant OHL concentration was dependent on the fimbrolide concentration with the detection limit below 1 ppm, indicating that this assay is a sensitive method for screening AHL inhibitors.

• 약학회지
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• 제45권2호
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• pp.147-152
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• 2001

The phytochemical study of the aerial parts of Artemisia sylvatica (Asteraceae) led to the isolation of nine sesquiterpene lactones, l$\alpha$-hydroperoxy-rupicolin A acetate (1), rupicolin B acetate (2), rupicolin A acetate (3), l$\alpha$-hydroxy-4$\alpha$-hydroperoxy-bishopsolicepolide (4), 1$\alpha$-hydroperoxy-4$\beta$-hydroxy-8$\alpha$-acetoxy-guaia-2,9,11 (13)-triene-6$\alpha$,12-oxide (5), 1$\alpha$-hydroperoxy-4$\alpha$-hydroxybishopsolicepolide (6), l$\alpha$,4$\beta$-dihydroxy-8$\alpha$-acetoxy-guaia-2,9,11(13)-triene-6$\alpha$,12-olive (7), rupicolin A (8) and l$\alpha$,4$\alpha$-dihydroxy-bishopsolicepolide (9). Their structures were established by chemical and spectroscopic methods.

• 생명과학회지
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• 제15권1호
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• pp.147-151
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• 2005

양귀비의 성분중 하나인 $(-)-\alpha-narcotine$은 ethyl chloroformate와 가온반응시 diastereomeric chloro-carbamate 혼한물과 Z/E-enol lactone혼합물을 생성하였는데 이 중에서 Z/E-isomer의 생성비를 HPLC로 측정한 결과 Z:E=1:1.12로 나타나 열역학적으로 불안정한 E-isomer가 다소 많이 생성되었다. 그러나 이 isomer 혼합물을 chromatography로 각각 분리 한 결과, 그 생성 비는 Z:E=7:1로 나타나 분리도중에 column 내 에서 E-isomer가 보다 안정한 Z-isomer로 대부분 변하였음을 알 수 있었다. Z/E-isomer의 생성비가 유사한 구조의 화합물에서 어떻게 변하는지를 관찰하기 위하여 $\beta-narcotine$, deuterated $\beta-narcotine$ 및 $\beta-hydrastine$을 대상으로 동일한 조건하에 반응시킨 결과, 이들의 isomer 생성비율이 구조에 따라 크게 차이가 있음을 알 수 있었으며 그 이유를 설명하였다. 한편, 일반적인 보고와는 달리, narcotine에서 생성된 안정한 Z-isomer는 광화학반응에 의해 불안정한 E-isomer로 쉽게 변한다는 사실도 확인하였다.

• Archives of Pharmacal Research
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• 제29권11호
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• pp.937-941
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• 2006

Ixeris dentata forma albiflora was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_{2}O$. Eight sesquiterpenes were isolated through repeated silica gel and octadecyl silica gel ($C_{18},\;ODS$) column chromatography of the EtOAc and n-BuOH fractions. Physicochemical analysis using NMR, MS and IR revealed the chemical structures of the sesquiterpenes, which were zaluzanin (1), 9a-hydroxyguaian-4(15), 10(14), 11 (13)-triene-6, 12-olide(2), $3{\beta}-O-{\beta}-D-glucopyranosyl-8{\beta}-hydroxyguaian$-4(15), 10(14)-diene-6, 12-olide (3), $3-O-{\beta}-D-glucopyranosyl-8{\beta}-hydroxyguauan$-10(14)-ene-6, 12-olide (4), ixerin M (5), glucozaluzanin C (6), crepiside I (7), and ixerin D (8). This is the first time that these sesquiterpene lactones have been isolated from this plant. Compounds 1, 2 and 7 revealed relatively high cytotoxicities on human colon carcinoma cell and lung adeno-carcinoma cell, while compounds 5 and 7 showed acyl-CoA: cholesterol acyltransferase (ACAT) inhibitory activity.