• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.601-608
• /
• 1997

In order to search for the way to utilize rice hull as a renewable resource, the inhibition on ${\alpha}-glucosidase$ and the fractionation of rice hull extract was investigated. An ethanol extract of rice hull from Japonica-type rice seeds exhibited 30% inhibitory activity on rat intestinal brush border ${\alpha}-glucosidase$ (1.4 mU/mL) in vitro at the concentration of 0.8 mg/mL using 6 mM p-nitrophenyl ${\alpha}-D-glucopyranoside$ as a substrate $(IC_{50}\;162\;mg/mL)$. Among the fractions obtained by partitioning the ethanol extract successively with solvents, the ethyl acetate fraction at the concentration of 0.8 mg/mL was found to exhibit the most potent inhibitory activity i.e. 65% inhibition of ${\alpha}-glucosidase\;(IC_{50}\;0.14\;mg/mL)$. Silica gel column chromatography of the ethyl acetate fraction exhibited slightly higher (90%) inhibitory activity, and its subsequent fractionation by Sephadex LH-20 column chromatography did not improve inhibitory activity. Considering the inhibitory activity and yield, the ethyl acetate fraction obtained by the solvent-partitioning process would be a candidate for the hypoglycemic food if it has in vivo effectiveness.

• YAKHAK HOEJI
• /
• v.44 no.1
• /
• pp.87-94
• /
• 2000

In order to investigate the hepatoprotective constituents, Melonis Pedicellus was systematically extracted and fractionated with n-hexane, ethyl acetate, butanol and water Treatment of rats with ethyl acetate fraction reduced hepatic injuries induced by $\alpha$-naphthylisothiocyanate or D-galactosamine, whereas the components in water fraction showed protective effect only against D-galactosamine-induced hepatitis in rats. Two cucurbitacins and three sterols were isolated from ethylacetate fraction and their chemical structures were identified as cucurbitacin B, isocucurbitacin B, $\alpha$-spinasterol, stigmast-7-en-3-ol and stigmast-7-en-3-ol-0-$\beta$-D-glucopyranoside. Cucurbitacin B at the dose of 1 mg/kg (p.o.) signifcantly increased in bile flow in rats with ANIT-induced cholestasis. Isocucurbitacin B at 5 mg/hg (p.o.) showed signilicant protective effects against ANIT-induced cholestasis. These results showed that cucurbitacin B and isocucurbitacin B from Melonis Pedicellus may have hepatoprotective effect in rats with experimental cholestasis.

• Natural Product Sciences
• /
• v.12 no.1
• /
• pp.62-66
• /
• 2006

A steroidal saponin, $3-O-{\alpha}-L-rhamnopyranosyl-(1{\rightarrow}2)-[{\alpha}-L-rhamnopyranosyl-(1{\rightarrow}3)]-{\beta}-D-glucopyranosylpennogenin$ ;(1, spiroconazole A) was isolated from the tubers of Dioscorea bulbifera L. var sativa and $^1H-and\;^{13}C-NMR$ assignment was completed using HMBC correlation. In addition, four phenolic substances, 2,7-dihydroxy-4-methoxyphenanthrene (2), quercetin (3), $quercetin-3-O-{\beta}-D-glucopyranoside$ (4), and $quercetin-3-O-{\beta}-D-galactopyranoside$ (5) were also isolated.

• Korean Journal of Pharmacognosy
• /
• v.41 no.3
• /
• pp.180-184
• /
• 2010

The antioxidant activity of Desmodium oldhami (Leguminosae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of D. oldhami showed the strong antioxidant activity. Five compounds, kaempferol-3-O-rhamnopyranoside (afzeline) (1), quercetin-3-O-[$\alpha$-L-rhamnopyranosyl($1{\rightarrow}6$)-$\beta$-Dglucopyranoside] (rutin) (2), kaempferol-3-O-glucopyranoside (astragalin) (3), genistein-7-O-$\beta$-D-glucopyranoside (genistin) (4), kaempferol-3-O-rutinoside (5) were isolated from the active ethyl acetate soluble fraction of D. oldhami through repeated silica gel and Sephadex LH-20 column chromatography. Among them, compound 2 showed the most significant antioxidative effect on DPPH free radical scavenging test. Compounds 1-5 are reported for the first time from this plant.

• Journal of Microbiology and Biotechnology
• /
• v.5 no.4
• /
• pp.188-193
• /
• 1995

A Brevibacterium flavum gene coding for glucose permease of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing the Escherichia coli ZSCl13 mutations affecting a ptsG gene with the B. flavum genomic library. From the E. coli clone grown as red colony on a MacConkey plate supplemented with glucose as an additional carbon source, a recombinant plasmid was isolated and named pBFT93. The plasmid pBFT93 was identified as carrying a 3.6-kb fragment of B. flavum chromosomal DNA which enables the E. coli transformant to use glucose or man nose as a sole carbon source in an M9 minimal medium. The non-metabolizable sugar analogues, 2-deoxy-D-glucose (2-DG) and methyl-$\alpha$-D-glucopyranoside (MeGlc) affected the growth of ZSCl13 cells carrying the plasmid pBFT93 on minimal medium supplemented with non-PTS carbohydrate, glycerol, as a sole cabon source, while the analogues did not repress the growth of ZSCl13 cells without pBFT93. It was also found that both $2-deoxy-D-[U-^{14}C]glucose{\;}and{\;}methyl-{\alpha}-D-[U-^{14}C]glucopyranoside$ could be effectively transported into ZSCl13 cells transformed with plasmid pBFT93. Several in vivo complementation studies suggested that the B. flavum DNA in pBFT93 encodes a glucose permease specific for glucose and mannose.

• YAKHAK HOEJI
• /
• v.40 no.3
• /
• pp.335-339
• /
• 1996

Optimal medium for growth and glycosidases production of Bacteroides JY-6, an human intestinal bacterium, was general anaerobic medium or tryptic soy broth containing sod ium thioglycolate and ascorbic acid. By cocultivation of Staphylococcus R-48, Bacteroides JY-6 could be cultured in LB broth unable to culture JY-6. Heated Staphylococcus R-48 was also the inducer of the production of Bacteroides JY-6 glycosidases. These glycosidases were induced well by natural flavonoid glycosides, such as poncirin, naringin and rutin, but were not by synthetic substrates, p-nitrophenyl ${\beta$-D-glucopyranoside and p-nitrophenyl ${\alpha}$-L-rhanmopyranoside.

• Journal of Forest and Environmental Science
• /
• v.13 no.1
• /
• pp.153-165
• /
• 1997

Hydroxyl radicals were detected and their qualitative yields were estimated by using chemiluminescence method and $\gamma$-irradiation technique in oxygen or chlorine dioxide radicals bleaching conditions. The correlation of hydroxyl radical formation and lignin model(Apocynol) or carbohydrate model($\alpha$-D-glucopyranose and methyl-$\beta$-D-glucopyranoside) degradation was studied in the presence of metal ion or without metal ion. The results showed that the presence of metal ions efficiently affected the formation of hydroxyl radicals in oxygen bleaching process, in the order of $Cu^{2+}$ > $Mn^{2+}$ > $Mg^{2+}$ > $Fe^{2+}$, and these metal gave also rise to the degradation of carbohydrate. But it was found that the addition of $100{\mu}m\;Mg^{2+}$ gave an efficient protection against carbohydrate degradation and suppressed the hydroxyl radical formation under oxygen bleaching conditions. And the presence of $Cu^{2+}$ had a detrimental effect on the stability of carbohydrates, whereas the addition of $3{\mu}m\;Mn^{2+}$ surprisingly had a small protective effect on methyl--$\beta$-D-glucopyranoside. In the $ClO_2$ radical bleaching conditions the hydroxyl radical expected to generate from water or substrates was not detected in the presence of metals.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.2
• /
• pp.242-247
• /
• 1997

A flavone glycoside was separated from the aerial part of Circium japonicum var ussuriense Kitamura and the effect on cardiovascular system was investigated. The cadiovascular contractility of this compound was observed in the artria and aortae from normal rats. It increased the spontancous beat in right atria and the contractile force in left atria, and caused the contraction of thoracic aortae. For the blood pressure, it had ascending effect. The effective component, which acted on stimulation and contraction in the artria and aortae of rats was fractionated with n-BuOH, separated and identified by column chromatography, UV, IR, $^1H-NMR$ and $^{13}C-NMR$. The chemical structure for this component was determined to be $hispidulin-7-{\alpha}-rhamnopyranosyl(1{\rightarrow}2)-{\beta}-D-glucopyranoside$.

• Korean Journal of Pharmacognosy
• /
• v.38 no.3 s.150
• /
• pp.222-226
• /
• 2007

Seven compounds, scopoletin (1), p-hydroxyphenethyl trans-ferulate (2), $1-({\alpha}-L-rhamnosyl(1\;{\rightarrow}\;6)-{\beta}-D-glucopyranosyloxy)-3,4,5-trimethoxybenzene$ (3), benzyl ${\alpha}-L-rhamnopyranosyl(1\;{\rightarrow}\;6)-{\beta}-D-glucopyranoside$ (4), suberic acid (5), sebacic acid (6) and scopolin (7) were isolated from the methanol extract of the roots of Althaea rosea Canival. Compounds $1\;{\sim}\;7$ were first isolated from this plant. The isolated compounds were tested for their cytotoxicity against human cancer cell lines using a SRB method in vitro.

• Korean Journal of Pharmacognosy
• /
• v.38 no.1
• /
• pp.76-83
• /
• 2007

In this study, three triterpenoids, two steroids and nine flavonoids were isolated from the leaves of Alnus firma Sieb. et Zucc. On the basis of spectroscopic evidences, the structures of these compounds were established as ${\beta}$-amyrin acetate, ${\beta}$-amyrin, ${\beta}$-sitosterol, alnustic acid methyl ester, ${\beta}$-sitosterol glucoside, pinocembrin, alnustinol, quercetin, quercetin-3-O-${\alpha}$-L-arabinofuranoside, quercetin-3-O-${\alpha}$-L -rhamnopyranoside, quercetin-3-O-${\beta}$-D-glucopyranoside, myricetin-3-O-${\beta}$-D-galac-topyranoside, (+)-catechin and (-)-epicatechin.