• Archives of Pharmacal Research
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• v.27 no.1
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• pp.25-30
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• 2004

Combinatorial homoserine lactone mixtures and individual products were obtained from the methionine-functionalized resin in solid-phase synthesis. The four-step process consisting of a coupling step of an N-Fmoc-L-methionine, deprotection of N-Fmoc group, N-coupling with a carboxylic acid, and cleavage reaction through a polymer supported strategy is described. Gas chromatography-mass selective detector (GC-MSD) techniques provide the most powerful methods for identifying both the combinatorial mixtures and individual products.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.189.2-189.2
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• 2000

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.174.2-174.2
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• 2003

Quorum sensing, a gene expression in response to population density, is regulated by chemical signals, most of which are acylated homoserine lactones (AHLs). The AHL derivatives have been reported to regulate bioluminescence, virulence factors and / or swarming motility in bacteria. It is hypothesized that higher organisms may have evolved specific means to interfere with bacterial communication as exemplified in the AHL-antagonistic activity of halogenated furanones isolated from the Australian macroalga Delisea pulchra. (omitted)

• Journal of Environmental Science International
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• v.26 no.11
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• pp.1275-1284
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• 2017

Acyltransferase (AT) catalyzes the transfer of an acyl moiety from acyl-coenzyme A (acyl-CoA) to an acceptor. ATs play important roles in the maintenance of homeostasis in the human body and have been linked to various diseases; therefore, several ATs have been proposed as potential targets for the treatment or prevention of such diseases. The AT family includes acyl-CoA:cholesterol AT (ACAT), diacylglycerol AT, and monoacylglycerol AT for the metabolism of lipids. Furthermore, recent molecular biological studies revealed the existence of their isozymes with distinct functions in the body. ACAT plays a critical role in the formation of cholesteryl esters from cholesterol and fatty acids, and is a potential target for treating hypercholesterolemia. During an experiment designed to discover biologically active compounds from herbal medicines, we isolated two known guaianolide sesquiterpene lactones from Chrysanthemum boreale Makino (Compositae). The lactones were characterized from their spectroscopic data (NMR, IR, MASS). These compounds were subjected to ACAT inhibition assay. Here, we report the isolation and structural elucidation of the compounds 8-o-acetyl-2-methoxy-10-hydroxy-3,11(13)-guaiadiene-12,6-olide and 8-acetyl-3,10-hydroxy-4(15),11(13)-guaiadiene-12,6-olide. In the ACAT inhibition assay, compound 1 showed strong inhibitory activity, with an $IC_{50}$ value $45{\mu}g/mL$, whereas compound 2 did not exhibit significant inhibitory activity with an over $100{\mu}g/mL$.

• Food Science and Preservation
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• v.6 no.2
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• pp.206-215
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• 1999

Volatile flavor components in five varieties, Bekdo, Chundo, Yumung, Daegubo and Hwangdo, of peach (Prunus persica L.) were extracted by SDE (Simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethylether(1:1, v/v) as an extract solvent. Analysis of the concentrate by capillary gas chromatography and gas chromatography-mass spectrometry led to the identification of 83, 85, 70, 74 and 66 components in Bekdo, Chundo, Yumung, Daegubo and Hwangdo, respectively. Aroma patterns (29 alcohols, 27 ketones, 18 aldehydes, 9 esters, 5 ethers, 3 acids, 6 terpene and derivatives, and 26 miscellaneous) were identified and quantified in five cultivars. Ethyl acetate, hexanal, o-xylene, (E)-2-hexenal, hexanol, (E)-2-hexen-1-ol, benzaldehyde, r-decalactone and r-dodecalactone were the main components in each samples, though there were several differences in composition of volatile components. Beside C$\_$6/ compounds, a series of saturated and unsaturated r- and $\delta$-lactones ranging from chain length C$\_$6/ to C$\_$l2/, with concentration maxima for r-decalactone and r-dodecalactone, were a major class of constituents. Lactones and peroxidation products of unsaturated fatty acid (i.e. C$\_$6/ aldehydes and alcohols) were major constituents of the extract.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.98-105
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• 1998

We measured seedling growth, foliar nutrient and extract concentrations of 3-year-old Ginkgo biloba seedlings growing in a nursery following a single fertilization with nitrogen (N), phosphorus (P) and nitrogen plus phosphorus (N+P) fertilizers. Fertilization did not change foliage, stem and root biomass of the seedlings except for the high N+P treatment, Foliar N and P concentrations following fertilization varied according to the amount of fertilizers. In general, foliar N and P concentrations increased with fertilization, but fertilization with 400kg N/ha and 100kg P/ha decreased foliar N and P concentrations, respectively. Seedling growth and foliar nutrient concentrations showed that N and P were the growth-limiting nutrients in our study site. It was found that fertilization reduced the concentrations of secondary metabolites (Ginkgo flavon glycosides and terpene lactones) in foliages. It seemed there was a relationship between foliage biomass production and secondary chemicals in G. biloba seedlings.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.218-222
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• 2008

This study was carried out to establish standard analytical methods for Ginkgo biloba leaf extract. Ginkgo flavonoids, terpene lactones, ginkgolic acids were employed as reference compounds for analytical method. Analytical method of US Pharmacopoeia was adopted for flavonoids and terpene lactones, and a new method was developed for ginkgolic acids. Analytical methods established in this study could be applied to a reasonable and unified quality control of G. biloba leaf extract.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.147-151
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• 2005

A$(-)-\alpha$-narcotine from Papaver sommiferum was refluxed with ethyl chloroformate to give the diastereomeric chloro-carbamate mixture and the Z/E-enol lactones as Z:E=1:1.1 ratio in HPLC analysis. After photoisomerization with UV (254 nm), the Z/E ratio was drastically changed to Z:E=7:1, which may indicate that the E-isomer was easily converted to the Z-isomer due to photoisomerization. The photoisomerization of the Z/E-enol lactones and the different stereochemistry of the degradation product of $\beta-narcotine$, deuterated $\beta-narcotine$ and $\beta-narcotine$ with ethyl chloroformate will also be discussed.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.74-78
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• 1999

Nine sesquiterpene lactones, which were isolated from Hemisteptia lyrata Bunge, Chrysanthemum zawadskii Herbich var. latilobum Kitamura and Chrysanthemum boreale Makino were evaluated for the inhibition upon the nitric oxide release from the Raw cell and for the ACAT (acyl Co A: cholesterol acyltransferase) inhibitory assay. In the nitric oxide release inhibitory experiment, hemistepsin B $(IC_{50}\;=\;0.05\;{\mu}g/ml,\;0.15\;{\mu}M),$ cumambrin B, tulipinolide and costunolide exhibited strong inhibition with $IC_{50}$ values $0.05\;{\mu}g/ml\;(0.15\;{\mu}M),\;0.1\;{\mu}g/ml\;(0.38\;{\mu}M),\;0.2\;{\mu}g/ml\;(0.69\;{\mu}M)$ and $0.2\;{\mu}g/ml(0.86\;{\mu}M),$ respectively. In the ACAT inhibitory assay, angeloylcumambrin B, tigloylcumambrin B, tulipinolide and costunolide exhibited strong inhibition with $IC_{50}$ values $33\;{\mu}g/ml\;(95.4\;{\mu}M),\;22\;{\mu}g/ml\;(63.6\;{\mu}M),\;38\;{\mu}g/ml\;(151\;{\mu}M)$ and $17\;{\mu}g/ml(73.3\;{\mu}M),$ respectively, whereas other compounds did not exhibit significant activity against ACAT above $100\; {\mu}g/ml.$.

• Korean Journal of Pharmacognosy
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• v.29 no.3
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• pp.243-247
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• 1998

A diverse panel of human tumor cell lines and a mouse melanoma cell line (B16-F1) were used for the cytotoxicity test of the nine sesquiterpene lactones with ${\beta}-methylene-{\gamma}-lactone$ group isolated from Hemisteptia lyrata, Chrysanthemum zawadskii and Chrysanthemum boreale. In the cell adhesion inhibitory activity test against B16-F1 mouse melanoma cell, hemistepcin B, cumambrin B, costunolide and tulipinolide were shown significant activities with $IC_{50}$ range of 2.2, 4.1, 0.9 and $0.3\;{\mu}g/ml$, respectively. In the cytotoxicity test against human tumor cells, the most active compound was costunolide having $IC_{50}$ values of below $0.3\;{\mu}g/ml$ against all the tested cell lines except for UACC62. Cumambrin A, hendelin and costunolide exhibited more strong activity against HCT15 and UO-31 cell lines than a positive control, adriamycin. All tested compounds showed an $IC_{50}$ values of below $5.0\;{\mu}g/ml$ against all the tested cell lines.