• YAKHAK HOEJI
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• v.33 no.3
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• pp.206-210
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• 1989

Bromolactonization of 2-Substituted-1-cyclohexenyl-1-acetic acid (1) with 1,3-dibromo-5,5-dimethylhydantoin (dibromantin) in N,N-dimethylformamide gave the corresponding ${\gamma}-bromo-{\beta}-lactone$ (2) and ${\beta}-bromo-{\gamma}-lactone$ (3). The effect of the substituents, the reaction temperature, and the solvent on the regioselectivity was discussed.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2398-2402
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• 2009

Ten steroidal compounds as impurities in canrenone were isolated from the enriched mother liquor by using various chromatographic methods. Their structures were elucidated by spectrometric analysis, among which three new compounds were characterized as 3-(3-oxo-7$\alpha$-(ethoxycarbonyl)methyl-17$\beta$-hydroxy-4-androsten-17$\alpha$-yl) propionic acid $\gamma$-lactone (1), 3-(3-oxo-7$\alpha$-ethoxy-17$\beta$-hydroxy-4-androsten-17$\alpha$-yl) propionic acid $\gamma$-lactone (2) and 3-(3-oxo- 5$\beta$-propionic acid-$\gamma$-lactone-6$\beta$,17$\beta$-hydroxy-4-androstan-17$\alpha$-yl) propionic acid $\gamma$-lactone (3).

• Archives of Pharmacal Research
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• v.24 no.5
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• pp.416-417
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• 2001

A new triterpene lactose named patrinolide A (7) has been isolated from the roots of Patrinia scabiosaefolia (Valerianaceae). Its structure was determined to be 11$\beta$,21$\beta$-dihydroxy-3-oxooleanan-28,13$\beta$-olide on the basis of spectral analysis, including 2D-NMR techniques.

• Archives of Pharmacal Research
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• v.27 no.10
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• pp.1016-1019
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• 2004

The chromatographic separation of a methylene chloride extract of Artemisia rubripes led to the isolation of a new sesquiterpene lactone (3), together with four known compounds, a coumarin (2) and three terpenes (1, 4, and 5). Their structures were characterized to be $1{\beta},6{\alpha}$- dihydroxy-4(15)-eudesmene (1), scopoletin (2), $1{\alpha},4{\beta}-dihydroxy-8{\alpha}$-acetoxy-guaia-2,10(14), 11(13)-triene-6,12-olide (3), $1{\alpha},4{\beta}$ -dihydroxy-8${\alpha}$-acetoxy-guaia-2,9,11(13)-triene-6,12-olide (4), and $\beta$ -sitosterol-3-O-${\beta}$-D-glycoside (5) by spectroscopic means.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.473-477
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• 1995

The dichloromethane extracts of the above ground parts of Hymenoxys brachyactis afforded three sesquiterpene lactones already reported, one new sesquiterpene lactone, biennin C and hispidulin as known toxic flavone. Structures of all compounds were established by spectroscopy and biennin C was determined as an adduct of the modified pseudoguanolide and hymenoxon by Gas Chromatograpy and MS spectrometer These sesquiterpene lactones have the same ${\alpha},{\beta}$-unsaturated functional group like that of hymenovin which has been known as major toxic constituent of important livestock poison. And biennin C is also considered as toxic compound because of toxic hymenoxon.

• Korean Journal of Microbiology
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• v.43 no.2
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• pp.130-136
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• 2007

Natural 6-dodecen-4-olide (Butte lactone) was produced from plant oils containing high unsaturated fatty acids via two-stage microbial hiotransformation. After unsaturated fatty acids were liberated from plant oil by microbial lipase, these were converted to optically active hydroxyl fatty acid (HFA) by hydroxylation reaction of Pseudomonas sp. NRRLB-2994. When safflower oil containing >75% unsaturated fatty acid, linoleoic acid wasused, Pseudomonas sp. produced 8g/L of 10-hydroxy-12(z)-octadecanoicacid with average of 39.2% bioconversion efficiency during 48 hr biotransformation period. The recovered 10-hydroxy-12-octadecanoic acid was further bioconverted to 4-hydroxy-6-dodecenoic acid via partial ${\beta}-oxidation$ by Yarriowia lipolytica ATCC34088. 4-hydroxy-6-dodecenoic acid in culture was lactonized by lowering pH to 4.0 using $4N\;H_{2}SO_{4}$ and heating for 5 min to 6-dodecen-4-olide (Butter lactone). Natural 6-dodecen-4-olide had characteristic aroma properties when compared to 6-dodecan-4-oilde (dodecalactone) and 4-decen-4-olide (decalactone).

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.289-292
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• 2002

The ethyl acetate extract of the leaves of Ixeris sonchifolia afforded two new and two known sesquiterpene lactone glucosides of the guaiane-type, together with a known alkenol glucoside. The known compounds were identified as ixerin Z (1), ixerin Z-6'-p-hydroxyphenylace-tate (2), and (Z)-3-hexen-1-ol-$\beta$-D-glucopyranoside (3), respectively. The structures of the new compounds were elucidated as 11, 13a-dihydroixerin Z [4, 3-hydroxy-2-oxo-guaia-1 (10), $3-dien-5{\alpha},6{\beta},7{\alpha},11{\beta}H-12,6-olide-3-O-{\beta}-D-glucopyranoside],{\;}and{\;}3,10{\$beta}-dihydroxy-2-oxo-guaia-3,11(13)-dien-1{\alpha},5{\alpha},6{\alpha},7aH-12,6-olide-10-O-{\beta}-D-glucopyranoside$ (5), respectively. The cytotoxicity of these compounds against human hepatocellular carcinoma cell (HepG2) and human melanoma cell (SK-MEL-2) was evaluated.

• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1211-1218
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• 2006

The enantiomerically pure (2R,3S)- and (2R,3R)-3-amino-2-hydroxy-4-phenylbutanoic acids (AHPBA) 1 and 3 are readily obtained from D-glucono-a-lactone. Both AHPBAs are the structural key units of KMI derivatives which are the potent inhibitors of BACE 1 ($\beta$-secretase) and HIV protease. Additionally, the obtained AHPBAs 1 and 3 are converted to dipeptides of bestatin stereoisomers 2 and 4.

• Archives of Pharmacal Research
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• v.14 no.2
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• pp.143-146
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• 1991

A new synthetic sequence for the chiral lactone moiety of compactin was developed from $\alpha$-D-glucose in 9 steps via simultaneous reductive detosylation and epoxide-ring opening of 2, 3-epoxy-4-tosylate using NaBH_4$ to afford 2, 4-dideoxy sugar as a key intermediate.

• Mycobiology
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• v.40 no.3
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• pp.173-180
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• 2012

A ${\beta}$-glucosidase from Penicillium italicum was purified with a specific activity of 61.8 U/mg, using a chromatography system. The native form of the enzyme was an 88.5-kDa tetramer with a molecular mass of 354 kDa. Optimum activity was observed at pH 4.5 and $60^{\circ}C$, and the half-lives were 1,737, 330, 34, and 1 hr at 50, 55, 60, and $65^{\circ}C$, respectively. Its activity was inhibited by 47% by 5 mM $Ni^{2+}$. The enzyme exhibited hydrolytic activity for p-nitrophenyl-${\beta}$-D-glucopyranoside (pNP-Glu), p-nitrophenyl-${\beta}$-D-cellobioside, p-nitrophenyl-${\beta}$-D-xyloside, and cellobiose, however, no activity was observed for p-nitrophenyl-${\beta}$-D-lactopyranoside, p-nitrophenyl-${\beta}$-D-galactopyranoside, carboxymetyl cellulose, xylan, and cellulose, indicating that the enzyme was a ${\beta}$-glucosidase. The $k_{cat}/K_m\;(s^{-1}mM^{-1})$ values for pNP-Glu and cellobiose were 15,770.4 mM and 6,361.4 mM, respectively. These values were the highest reported for ${\beta}$-glucosidases. Non-competitive inhibition of the enzyme by both glucose ($K_i=8.9mM$) and glucono-${\delta}$-lactone ($K_i=11.3mM$) was observed when pNP-Glu was used as the substrate. This is the first report of non-competitive inhibition of ${\beta}$-glucosidase by glucose and glucono-${\delta}$-lactone.