• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.1011-1017
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• 2010

A novel dioscin-glycosidase that specifically hydrolyzes multi-glycosides, such as 3-O-${\alpha}$-L-($1{\to}4$)-rhamnoside, 3-O-${\alpha}$-L-($1{\to}2$)-rhamnoside, 3-O-${\alpha}$-L-($1{\to}4$)-arabinoside, and ${\beta}$-D-glucoside, on diosgenin was isolated from the Absidia sp.d38 strain, purified, and characterized. The molecular mass of the new dioscin-glycosidase is about 55 kDa based on SDS-PAGE. The dioscin-glycosidase gradually hydrolyzes either 3-O-${\alpha}$-L-($1{\to}4$)-Rha or 3-O-${\alpha}$-L-($1{\to}2$)-Rha from dioscin into 3-O-${\alpha}$-L-Rha-${\beta}$-D-Glc-diosgenin, further rapidly hydrolyzes the other ${\alpha}$-L-Rha from 3-O-${\alpha}$-L-Rha-${\beta}$-D-Glc-diosgenin into the main intermediate products of 3-O-${\beta}$-D-Glc-diosgenin, and subsequently hydrolyzes these intermediate products into aglycone as the final product. The enzyme also gradually hydrolyzes 3-O-${\alpha}$-L-($1{\to}4$)-arabinoside, 3-O-${\alpha}$-L-($1{\to}2$)-rhamnoside, and ${\beta}$-D-glucoside from [3-O-${\alpha}$-L-($1{\to}4$)-Ara, 3-O-${\alpha}$-L-($1{\to}4$)-Rha]-${\beta}$-D-Glc-diosgenin into diosgenin as the final product, exhibiting significant differences from previously reported glycosidases. The optimal temperature and pH for the new dioscin-glycosidase is $40^{\circ}C$ and 5.0, respectively. Whereas the activity of the new dioscin-glycosidase was not affected by $Na^+$, $K^+$, and $Mg^{2+}$ ions, it was significantly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, and slightly affected by $Ca^{2+}$ ions.

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.280-285
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• 2012

Six polyphenolic compounds, such as chlorogenic acid (CA), rutin (RT), isoquercitrin (IQT), quercetin-3-O-(6-O-malonyl)-${\beta}$-D-glucoside (QMG), astragalin (AG), kaempferol-3-O-(6-O-malonyl)-${\beta}$-D-glucoside (KMG), were isolated from mulberry leaves by a series of isolation procedures, such as Diaion HP-20, silica-gel, Sephadex LH-20, and ODS-A column chromatographies. The chemical structures of the phenolic compounds were identified by UV and NMR spectral analyses. Levels of polyphenols in mulberry leaves from six different mulberry cultivars ranged from 1,042.16 to 1,871.97 mg% per dry weight; Guksang cultivar showed the highest levels of polyphenols, whereas Gaeryangdaehwa contained the least polyphenol contents. Generally, levels of polyphenols in mulberry leaves decreased with increasing harvest time, except for Yoolmok, but increased with heat processing time, except QMG and KMG. These results suggest that the heat processed mulberry leaves of Guksang cultivar harvested in early May can be potentially useful sources for production of high quality mulberry leaf teas.

• Fisheries and Aquatic Sciences
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• v.24 no.12
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• pp.428-436
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• 2021

The aim of this study was to isolate and identify secondary metabolites from Sonchus brachyotus and evaluate their antioxidant and anti-inflammatory activities. In this study, we isolated three flavonoids from a 70% EtOH extract by Medium Pressure Liquid Chromatography (MPLC) and prep-High-Performance Liquid Chromatography (HPLC). To evaluate the biological activities (antioxidant and anti-inflammatory) of these flavonoids, their in vitro inhibitory activities against lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) generation, nitric oxide (NO) production, and prostaglandin E₂ (PGE₂) secretion were determined. We successfully identified three flavonoids, namely luteolin (1), luteolin-7-O-β-D-glucoside (2), and luteolin-7-O-β-D-glucuronide (3) by spectral analyses. Luteolin (1) at 20 ㎍/mL inhibited ROS generation, NO production, and PGE₂ secretion by 48.6%, 61.28% and 12.10%, respectively, and luteolin-7-O-β-D-glucoside (2) inhibited NO and PGE₂ generation by 67.03% and 20.82%, respectively. Luteolin (1) and luteolin-7-O-β-D-glucoside (2) showed similar anti-inflammatory activities; however, luteolin (1) was observed to be a stronger antioxidant. Besides antioxidant and anti-inflammatory activities, S. brachyotus extract containing luteolin (1) and luteolin-7-O-β-D-glucoside (2) is considered to possess diverse biological activities. The results indicate that S. brachyotus is an edible medicinal plant, which is believed to be significant resource of functional foods.

• Journal of Microbiology and Biotechnology
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• v.21 no.10
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• pp.1057-1063
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• 2011

Herein, a novel ginsenosidase, named ginsenosidase type IV, hydrolyzing 6-O-multi-glycosides of protopanaxatriol-type ginsenosides (PPT), such as Re, R1, Rf, and Rg2, was isolated from the Aspergillus sp. 39g strain, purified, and characterized. Ginsenosidase type IV was able to hydrolyze the 6-O-${\alpha}$-L-($1{\rightarrow}2$)-rhamnoside of Re and the 6-O-${\beta}$-D-($1{\rightarrow}2$)-xyloside of R1 into ginsenoside Rg1. Subsequently, it could hydrolyze the 6-O-${\beta}$-D-glucoside of Rg1 into F1. Similarly, it was able to hydrolyze the 6-O-$_{\alpha}$-L-($1{\rightarrow}2$)-rhamnoside of Rg2 and the 6-O-${\beta}$-D-($1{\rightarrow}2$)-glucoside of Rf into Rh1, and then further hydrolyze Rh1 into its aglycone. However, ginsenosidase type IV could not hydrolyze the 3-O- or 20-O-glycosides of protopanaxadiol-type ginsenosides (PPD), such as Rb1, Rb2, Rb3, Rc, and Rd. These exhibited properties are significantly different from those of glycosidases described in Enzyme Nomenclature by the NC-IUBMB. The optimal temperature and pH for ginsenosidase type IV were $40^{\circ}C$ and 6.0, respectively. The activity of ginsenosidase type IV was slightly improved by the $Mg^{2+}$ ion, and inhibited by $Cu^{2+}$ and $Fe^{2+}$ ions. The molecular mass of the enzyme, based on SDS-PAGE, was noted as being approximately 56 kDa.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.439-443
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• 2007

The effects of the methanol extract of the leaves of Brassica juncea and isorhamnetin $3-O-{\beta}-D-glucopyranoside$, major compound isolated from the ethyl acetate fraction of this plant on hepatic lipid peroxidation and drug-metabolizing enzymes, were evaluated in rats treated with bromobenzene. The extract and isorhamnetin $3-O-{\beta}-D-glucopyranoside$ of oral administration did not show any significant effects on activities of aminopyrine N-demethylase and aniline hydroxylase, enzymes forming toxic epoxide by bromobenzene as well as on glutathione content. However, both methanol extract and isorhamnetin $3-O-{\beta}-D-glucopyranoside$ significantly recovered the decreased activities of glutathione s-transferase and epoxide hydrolase, and also reduced the lipid peroxide level in rats treated with bromobenzene. From the results, the protections of this plant against bromobenzene-induced hepatotoxicity are thought to be via enhancing the activities of epoxide hydrolase and glutathione s-transferase, enzymes removing toxic epoxide, and reducing the lipid peroxide level.

• Journal of Applied Biological Chemistry
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• v.51 no.2
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• pp.57-60
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• 2008

Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.348-351
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• 2007

The stem barks of Fraxinus rhynchophylla was extracted with 95% EtOH, and the concentrated extract was successively partitioned with $CH_2Cl_2$, n-BuOH, and $H_2O$ in order to investigate the major phytochemicals. From the $CH_2Cl_2$ soluble fraction, a sterol (1) was isolated through the repeated silica gel column chromatographies. Three additional compounds (2-4) were isolated from the n-BuOH soluble fraction through silica gel, RP-18, and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated as daucosterol $(1;{\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside)$, caffeic acid (2), 6,8-dihydroxy-7-methoxycoumarin (3), and coniferaldehyde glucoside (4) by comparing their spectral data with those in the literatures. All isolates (1-4) were the first to be isolated from F. rhynchophylla.

• Archives of Pharmacal Research
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• v.28 no.8
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• pp.892-896
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• 2005

In order to isolate substances that inhibit the hemolytic activity of human serum against eryth-rocytes, we have evaluated whole plants of the Orostachys japonicus species with regard to its anti-complement activity, and have identified its active principles following activity-guided isolation. A methanol extract of the O. japonicus, as well as its n-hexane soluble fraction, exhibited significant anti-complement activity on the complement system, which was expressed as total hemolytic activity. A bioassay-guided chromatographic separation of the constituents resulted in the isolation of three known compounds 1-3 from the active n-hexane fraction. The structure of these compounds were analyzed, and they were identified as hydroxyhopanone (1), $\beta-sitosteryl-3-O-\beta-D-glucopyranosyl-6'-O-palmitate$ (2), and $\beta-sitosteryl-3-O-\beta-D-glucopyranoside$ (3), respectively. Of these compounds, compound 2 exhibited potent anti-complement activity $(IC_{50}=1.0\pm0.1{\mu}M)$ on the classical pathway of the complement, as compared to tiliroside $(IC_{50}=76.5\pm1.1{\mu}M)$, which was used as a positive control. However, compounds 1 and 3 exhibited no activity in this system.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.628-635
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• 2002

Five terpenes (1~5), three fatty acids (6~8), two sterols (9 and 11), and a monogalactosyldiacyl glycerol (10) were isolated from the methylene chloride extract of the aerial part of Cirsium setidens. Their chemical structures were determined to be $\alpha$-tocopherol (1), 25-hydroperoxycycloart-23-en-3$\beta$-o1 (2), 24-hydroperoxycycloart-25-en-3$\beta$-o1 (3), mokko lactone (4), transphytol (5), 9, 12, 15-octadecatrienoic acid (6), 9, 12-octadecadienoic acid (7), hexadecanoic acid (8), acylglycosyl $\beta$-sitosterol (9), (2R)-1, 2-O-(9z, 12z, 15z-dioctadecatrienoyl)-3-O-$\beta$-D-galactopyranosyl glycerol (10) and $\beta$-sitosterol glucoside (11) by spectral evidences. Compound 3 exhibited significant cytotoxic activity against five human cancer cell lines with its $ED_{50}$ values ranging from 2.66 to 11.25 $\mu$M.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1086-1090
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• 2006

The chromatographic separation of the MeOH extract from the twigs of Acer tegmentosum led to the isolation of ten phenolic compounds. The structures of these compounds were determined using spectroscopic methods as 3,7,3',4'-tetramethyl-quercetin (1), 5,3'-dihydroxy-3,7,4'-trimethoxy flavone (2), 2,6-dimethoxy-p-hydroquinone (3), (-)-catechin (4), morin-3-O-${\alpha}$-L-lyxoside (5), p-hydroxy phenylethyl-O-${\beta}$-D-glucopyranoside (6), 3,5-dimethoxy-4-hydroxy phenyl-1-O-${\beta}$-D-glucoside (7), fraxin (8), 3,5-dimethoxy-benzyl alcohol 4-O-${\beta}$-D-glucopyranoside (9) and 4-(2,3-dihydroxy propyl)-2,6-dimethoxy phenyl ${\beta}$-D-glucopyranoside (10). The compounds were examined for their cytotoxic activity against five cancer cell lines. Compound 3 exhibited good cytotoxic activity against five human cancer cell lines with $ED_{50}$ values ranging from $1.32\;to\;3.85\;{\mu}M$.