• Advances in Traditional Medicine
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• v.9 no.2
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• pp.192-199
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• 2009

Bioactivity-directed isolation has led to the isolation of (-)-ent-costunolide (1) as the major active compound from Hepatostolonophora paucistipula. This compound (1) was determined by spectroscopic data interpretation. This sesquiterpene lactone (1) inhibited the growth of the dermatophytic fungus Trichophyton mentagrophytes ATCC 28185, (4 mm inhibition zone at $15{\mu}g$/disc), cytotoxic activity to murine leukaemia cell lines ATCC CCL 46 P 388D1 ($IC_{50}$ 687 ng/ml, at $0.075{\mu}g$/disk), BSC monkey kidney cell lines (100% of well at $15{\mu}g$/disk) and antiviral activity to Herpes simplex virus (0.25 mg/ml, 100% of well at $7.5{\mu}g$/disk) and Polio virus (0.125 mg/ml, 100% of well at $3.75{\mu}g$/disk). These results suggest that (-)-ent-costunolide (1) has potential antimicrobial and cytotoxic agents.

• YAKHAK HOEJI
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• v.51 no.2
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• pp.145-149
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• 2007

Saussurea Radix, the dried roots of Saussurea lappa Clark (Compositae), has been used in oriental traditional medicine for aromatic stomachic. Present study was carried out for the anticancer effect of Saussurea Radix. Bioassay-directed fractionation of Saussurea Radix led to the isolation of two sesquiterpenes, dehydrocostuslactone (1) and costunolide (2). The structures of 1 and 2 were elucidated by spectral methods (MS, IR, $^1$H and $^{13}$C NMR). These compounds showed a potent cell proliferation activity against human breast cancer cell MCF-7 and MDA-MB-453.

• Journal of Microbiology
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• v.43 no.spc1
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• pp.101-109
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• 2005

To gain maximal benefit in a competitive environment, single-celled bacteria have adopted a community genetic regulatory mechanism, known as quorum sensing (QS). Many bacteria use QS signaling systems to synchronize target gene expression and coordinate biological activities among a local population. N-acylhomoserine lactones (AHLs) are one family of the well-characterized QS signals in Gram-negative bacteria, which regulate a range of important biological functions, including virulence and biofilm formation. Several groups of AHL-degradation enzymes have recently been identified in a range of living organisms, including bacteria and eukaryotes. Expression of these enzymes in AHL-dependent pathogens and transgenic plants efficiently quenches the microbial QS signaling and blocks pathogenic infections. Discovery of these novel quorum quenching enzymes has not only provided a promising means to control bacterial infections, but also presents new challenges to investigate their roles in host organisms and their potential impacts on ecosystems.

• Korean Journal of Pharmacognosy
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• v.24 no.3
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• pp.192-196
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• 1993

Essential oil of the root of Angelica decursiva(Miq.) Fr. et Sav. (Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain ten monoterpenes such as ${\alpha}-pinene$ (7.0%) etc. Three hydrocarbons, two aldehydes, three sesquiterpenes, two sesquiterpene alcohols, one aromatic compounds, one ketone, isobonyl acetate and two lactones were tentatively identified.

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.612-617
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• 1991

The approximate rates and stoichiometry of the reaction of excess 1,3,2-biphenyldioxaborepin [2,2'-biphenoxyborane (BPB)] with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, hydride to compound being 4 : 1, room temperature) was examined in order to define the characteristics of the reagent for selective reductions and compare its reducing power with those of other substituted boranes. The results indicate that BPB is unique and the reducing power is much stronger than that of other dialkoxyboranes, such as catecholborane and di-s-butoxyborane. BPB reduces aldehydes, ketones, quinones, lactones, tertiary amides, and sulfoxides readily. Carboxylic acids, anhydrides, esters, and nitriles are also reduced slowly. However, the reactions of acid chlorides, epoxides, primary amides, nitro compounds, and disulfides with this reagent proceed only sluggishly.

• Natural Product Sciences
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• v.24 no.4
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• pp.253-258
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• 2018

Two meroterpenoids (1 and 2) along with twelve known compounds (3 - 14) were isolated from the culture broth of a Penicillium sp. fungus collected from Chuja-do, Korea. Based on the results of a combination of spectroscopic analyses, the new compounds, preaustinoids E (1) and F (2), were determined to be epimeric austintype penta-cyclic lactones.

• Natural Product Sciences
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• v.25 no.1
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• pp.23-27
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• 2019

From the pericarps of Litsea japonica (Thunb.) Jussieu, eighteen butanolide derivatives (1 - 18) were evaluated for their cytotoxic activity against HeLa, HL-60, and MCF-7 cells. Compounds 1-9 with 2-alkylidene-3-hydroxy-4-methylbutanolides structure exhibited cytotoxic activities against cancer-cell lines. Among them, compound 8 (litsenolide $D_2$) exhibited the most potent cytotoxicity against the tested cell lines, including HeLa, HL-60, and MCF-7, with $IC_{50}$ values of $17.6{\pm}1.3$, $4.2{\pm}0.2$, and $12.8{\pm}0.0{\mu}M$, respectively. Compound 8 induced apoptosis in a dose-dependent manner. Annexin V/Propidium Iodide (PI) double staining confirmed that 8 effectively induced apoptosis in MCF-7 cells. To the best of our knowledge, we have reported cytotoxic activity of butanolides from L. japonica against these cancer-cell lines for the first time.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.304-310
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• 1987

The approximate rate and stoichiometry of the reaction of excess di-s-butoxyborane with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, $25^{\circ}C)$ were examined in order to define the characteristics of the reagent for selective reductions. And the catalytic effect of lithium tetra-s-butoxyborate on the reaction of di-s-butoxyborane was also studied in order to increase the utility of this reducing system. Di-s-butoxyborane reacts only with simple aldehydes. However the addition of 2.5 mole % of lithium tetra-s-butoxyborate shows the tremendous rate enhancement of reaction for aldehydes, ketones, anhydrides, acid chlorides, lactones, and epoxides. This catalytic effect is assumed to in situ formation of lithium trialkoxyborohydride.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.224.1-224.1
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• 2003

Recent studies have revealed that bacterial biofilm production by the gram-negative bacteria is regulated by the quorum sensing signaling molecules, AHLs (N-acyl homoserine lactones). This suggests that inhibiting the AHLs could enhance the effects of antibacterial agents. Halogenated furanones purified from the red algae Delisea pulchra have been known to decrease quorum sensing responses by competitive inhibition of the AHLs. (omitted)

• Journal of Integrative Natural Science
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• v.2 no.1
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• pp.18-23
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• 2009

This minireview provides the chosen examples of our recent discoveries in the polymerization of hydrosilanes, dihydrosilole, lactones, and vinyl derivatives using various catalysts. Hydrosilanes and lactones copolymerize to give poly(lactone-co-silane)s with $Cp_2MCl_2$/Red-Al (M = Ti, Zr, Hf) catalyst. Hydrosilanes (including dihydrosilole) reduce noble metal complexes (e.g., $AgNO_3$, $Ag_2SO_4$, $HAuCl_4$, $H_2PtCl_6$) to give nanoparticles along with silicon polymers such as polysilanes, polysilole, polysiloxanes (and silicas) depending on the reaction conditions. Interestingly, phenylsilane dehydrocoupled to polyphenylsilane in the inert nitrogen atmosphere while phenylsilane dehydrocoupled to silica in the ambient air atmosphere. $Cp_2M/CX_4$ (M = Fe, Co, Ni; X = Cl, Br, I) combination initiate the polymerization of vinyl monomers. In the photopolymerization of vinyl monomers using $Cp_2M/CCl_4$ (M = Fe, Co, Ni), the photopolymerization of MMA initiated by $Cp_2M/CCl_4$ (M = Fe, Co, Ni) shows while the polymerization yield decreases in the order $Cp_2Fe$ > $Cp_2Ni$ > $Cp_2Co$, the molecular weight decreases in the order $Cp_2Co$ > $Cp_2Ni$ > $Cp_2Fe$. For the photohomopolymerization and photocopolymerization of MA and AA, the similar trends were observed. The photopolymerizations are not living. Many exciting possibilities remain to be examined and some of them are demonstrated in the body of the minireview.