• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.360-367
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• 1990

The several glycoside hydrolysing enzymes related to rutin degradation are found to be rhamnosidase, glucosidase and rutinosidase. Rutinosidase was purified to electrophoretic homogeneity from cell extracts of rutin-degrading strain, MT-57, which was identified as a Arthrobacter sp. Its molecular weight was estimated to be 42, 000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 40, 000 by gel filtration. The optimum pH for enzyme was found to be 7.5, and relatively stable in alkaline solution. The optimum temperature for enzyme was $45^{\circ}C$, being stable up to $50^{\circ}C$ for 20 min. The Bm value of enzyme for rutin was 0.5 $\mu \textrm m$. The enzyme activity was increased by the chelating agent such as EDTA, $NaN_3$, and 8-hydroxyquinoline, was strongly inhibited by $CO_{2+}, Ni^{2+}$, and $Cu^{2+}$. The enzyme had high substrate specificity in the rutinoside.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.269-273
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• 1996

We investigated the effects of ginseng glycosides and their aglycones on processes of single ion channel formation and channel properties. The glycosides, Rg, and Rb, , and their aglycones, 20-(S)-protopanaxatriol (PT) and 20-(S)-protopanaxadiol (PD) increased the membrane permeability for ions. PT, PD, Rg1, and Rb1; at concentrations of 0.5, 3.0, 10.0 and 30.0 $\mu\textrm{g}$/ml respectively; Induced single ion channel fluctuations with the life times in the range of 0.1~1005 in open states and conductances from 5 to 30 pS in 1 M KCI. At high concentrations of these substances, rapid fluctuations of transmembrane ion current with amplitude from hundred pS to dozen nS were observed. Against other substances, ginsenoside Rbl began to increase the membrane conductance at concentration of about 60 $\mu\textrm{g}$/ml without fluctuation of single ion channel. Membranes treated with PT, PD, Rg1 and Rb1 are more permeable to K+, than to Cl while zero current membrane potentials with 10 gradients of KCI were 12, 16, 8, 25 mV respectively. Key words : Membrane conductance, single ion channel, ginsenosides.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.800-805
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• 2007

Two endoglucanases with processive cellulase activities, produced from Fomitopsis palustris grown on 2% microcrystalline cellulose(Avicel), were purified to homogeneity by anion-exchange and gel filtration column chromatography systems. SDS-PAGE analysis indicated that the molecular masses of the purified enzymes were 47 kDa and 35 kDa, respectively. The amino acid sequence analysis of the 47-kDa protein(EG47) showed a sequence similarity with fungal glycoside hydrolase family 5 endoglucanase from the white-rot fungus Phanerochaete chrysosporium. N-terminal and internal amino acid sequences of the 35-kDa protein(EG35), however, had no homology with any other glycosylhydrolases, although the enzyme had high specific activity against carboxymethyl cellulose, which is a typical substrate for endoglucanases. The initial rate of Avicel hydrolysis by EG35 was relatively fast for 48 h, and the amount of soluble reducing sugar released after 96 h was $100{\mu}g/ml$. Although EG47 also hydrolyzed Avicel, the hydrolysis rate was lower than that of EG35. Thin layer chromatography analysis of the hydrolysis products released from Avicel indicated that the main product was cellobiose, suggesting that the brown-rot fungus possesses processive EGs capable of degrading crystalline cellulose.

• Natural Product Sciences
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• v.16 no.2
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• pp.68-74
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• 2010

Phytochemical investigation on the ethyl acetate and n-butanol fractions of Moutan Cortex resulted in the isolation and characterization of a new monoterpene glycoside (3) and twenty known monoterpene glycosides (1, 2, 4-21). The structure of 3 was determined by spectroscopic data interpretation and physico-chemical properties. Compounds 1 and 8 presented a remarkable inhibitory activity against lipoxygenase-1 (LOX-1) with $IC_{50}$ values of 45.2 and $37.5\;{\mu}M$, respectively. Compounds 9, 10, 13, 18, 19, and 21 showed significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect with $IC_{50}$ values of 9.8, 25.5, 6.4, 15.2, 18.7, and $23.7\;{\mu}M$, respectively. Benzoylpaeoniflorin (8), which exhibited the highest inhibitory effect with an $IC_{50}$ value of $37.5{\pm}0.7{\mu}M$, was further analyzed the inhibition kinetics by Lineweaver-Burk plots. Results indicated that 8 is a non-competitive inhibitor, and the kinetic parameter values were estimated to be ($31.04\;{\mu}M$, Ki), ($0.29\;{\mu}M/min$, $V_m$), and ($48.50\;{\mu}M$, $K_m$).

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.371-380
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• 2019

Termites are pests that cause serious economic and cultural damage by digesting wood cellulose. Termites are arthropods and have an epidermis surrounded by a chitin layer. To maintain a healthy epidermis, termites have chitinase (${\beta}$-1,4-poly-N-acetyl glucosamidinase, EC 3.2.1.14), an enzyme that hydrolyzes the ${\beta}$-1,4 bond of chitin. In this study, the amino acid sequence of the gene, which is presumed to be termite chitinolytic enzyme (NCBI accession no. KC477099), was obtained from a transcriptomic analysis of Reticulitermes speratus KMT001 in Bukhan Mountain, Korea. An NCBI protein BLAST search confirmed that the protein is a glycoside hydrolase family 18 (GH18). The highest homology value found was 47%, with a chitinase from Araneus ventricosus. Phylogenetic analysis indicated that the KC477099 protein has the same origins as those of arthropods but has a very low similarity with other arthropod chitinases, resulting in separation at an early stage of evolution. The KC477099 protein contains two conserved motifs, which encode the general enzymatic characteristics of the GH18 group. The amino acid sequences $Asp^{156}-Trp^{157}-Glu^{158}$, which play an important role in the enzymatic activity of the GH18 group, were also present. This study suggests that the termite KC477099 protein is a new type of chitinase, which is evolutionarily distant from other insect chitinases.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.410-417
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• 2016

Quercetin is a flavonoid usually found in fruits and vegetables. Aside from its antioxidative effects, quercetin, like other flavonoids, has a various neuropharmacological actions. Quercetin-3-O-rhamnoside (Rham1), quercetin-3-O-rutinoside (Rutin), and quercetin-3-(2(G)-rhamnosylrutinoside (Rham2) are mono-, di-, and tri-glycosylated forms of quercetin, respectively. In a previous study, we showed that quercetin can enhance ${\alpha}7$ nicotinic acetylcholine receptor (${\alpha}7$ nAChR)-mediated ion currents. However, the role of the carbohydrates attached to quercetin in the regulation of ${\alpha}7$ nAChR channel activity has not been determined. In the present study, we investigated the effects of quercetin glycosides on the acetylcholine induced peak inward current ($I_{ACh}$) in Xenopus oocytes expressing the ${\alpha}7$ nAChR. $I_{ACh}$ was measured with a two-electrode voltage clamp technique. In oocytes injected with ${\alpha}7$ nAChR copy RNA, quercetin enhanced $I_{ACh}$, whereas quercetin glycosides inhibited $I_{ACh}$. Quercetin glycosides mediated an inhibition of $I_{ACh}$, which increased when they were pre-applied and the inhibitory effects were concentration dependent. The order of $I_{ACh}$ inhibition by quercetin glycosides was Rutin${\geq}$Rham1>Rham2. Quercetin glycosides-mediated $I_{ACh}$ enhancement was not affected by ACh concentration and appeared voltage-independent. Furthermore, quercetin-mediated $I_{ACh}$ inhibition can be attenuated when quercetin is co-applied with Rham1 and Rutin, indicating that quercetin glycosides could interfere with quercetin-mediated ${\alpha}7$ nAChR regulation and that the number of carbohydrates in the quercetin glycoside plays a key role in the interruption of quercetin action. These results show that quercetin and quercetin glycosides regulate the ${\alpha}7$ nAChR in a differential manner.

• Archives of Pharmacal Research
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• v.27 no.4
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• pp.390-395
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• 2004

The methanol extract obtained from the aerial parts of Aceriphyllum rossii (Saxifragaceae) was fractionated into ethyl acetate (EtOAc), n-BuOH and $H_2O$ layers through solvent fractionation. Repeated silica gel column chromatography of EtOAc and n-BuOH layers afforded six flavonol glycosides. They were identified as kaempferol 3-O-$\beta$-D-glucopyranoside (astragalin, 1), quercetin 3-O-$\beta$-D-glucopyranoside (isoquercitrin, 2), kaempferol 3-O-$\alpha$-L-rhamnopyranosyl $(1{\to}6)-\beta$-D-glucopyranoside (3), quercetin 3-O$\alpha$-L-rharnnopyranosyl $(1{\to}6)-\beta$-D-qlucopyrano-side (rutin, 4), kaempferol 3-O-[$\alpha$-L-rharnnopyranosyl $(1{\to}4)-\alpha$-L-rhamnopyranosyl $(1{\to}6)-\beta$-D-glucopyranoside] (5) and quercetin 3-O-[$\alpha$-L-rhamnopyranosyl $(1{\to}4)\alpha$-L-rhamnopyranosyl $(1{\to}6)\beta$-D-glucopyranoside] (6) on the basis of several spectral data. The antioxidant activity of the six compounds was investigated using two free radicals such as the ABTS free radical and superoxide anion radical. Compound 1 exhibited the highest antioxidant activity in the ABTS $\{2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)\}$ radical scavenging method. 100 mg/L of compound 1 was equivalent to $72.1\pm1.4\;mg/L$ of vitamin C, and those of compounds 3 and 5 were equivalent to $62.7\pm0.5\;mg/L$ and $54.3\pm1.3\;mg/L$ of vitamin C, respectively. And in the superoxide anion radical scavenging method, compound 5 exhibited the highest activity with an $IC_{50}$ value of $17.6{\pm}0.3{\mu}M$. In addition, some physical and spectral data of the flavonoids were confirmed.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.16-22
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• 2005

Many chitosanases, glycosyl hydrolases that catalyze the degradation of chitosan, have been found in microorganism. In this paper, classification of the enzyme has been described, which is based on the amino acid sequence (families) and splitting patterns (subclasses). Glycohydrolytic mechanisms such as inversion and retention of the substrate anomer are also discussed in context of the families. Interrelationship among the primary structure, clan, anomeric conversion and the splitting patterns has been suggested. In addition, advanced definition of chitosanase was introduced through the investigation of enzymatic products from partially N-acetylated chitosan as a substrate.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.53-59
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• 2014

To evaluate the inhibitory effect of xanthine oxidase (XO) and aldehyde oxidase (AO), and antihyperuricemic effect by Aspergillus oryzae fermented Smilax china L. leaf extracts and fractions, we observed extracted yield by each solvent, the content of total polyphenol and total flavonoid (TF), the activities of XO and AO, and serum uric acid level. Extracted yield (g/kg) by 80% ethanol (EtOH) was 13.56, those of n-hexane, dichloromethane (DICM), ethylacetate (EtOAc) and n-butanol fraction (BuOH) were 1.35-3.33. Furthermore, total polyphenol content (mg/g-extract) of EtOAc fraction, BuOH fraction, DICM fraction and EtOH fraction is 478.07-501.26, 259.49-289.02, 165.03-232.27, 134.02-196.54, respectively. Those of fermented EtOAc and DICM fraction was 4.85 and 40.74% higher than that of non-fermented fraction, respectively, while the other fermented fractions were lower than those of non-fermented fractions. And total flavonoid content (mg/g-extract) of EtOAc fraction was higher than those of other fractions. Additionally, TF of fermented EtOAc and BuOH fraction is 10.56 and 60.17% higher, than that of fermented fraction, respectively, although those of the other fermented fractions was lower than that of non-fermented fractions. On the other hand, XO inhibitory activities of all fermented fractions was significantly higher than that of all non-fermented fraction, while those of fermented EtOAc (75.02%) and BuOH fraction (65.59%) was markedly higher than that of non-fermented fraction (39.42 and 5.34%), respectively. In addition, AO inhibitory activities of DICM and EtOAc fraction was 81.82 and 77.93% higher, respectively, than those of the other fractions, and those of fermented fractions as with XO were significantly higher than that of non-fermented fractions. Meanwhile, serum uric acid level (SU) of hyperuricemic control mice (HC, 6.98 mg/dL) was 1.83 folds higher than that of normal control (NC, 3.82 mg/dL). Furthermore, SU in the group treated with EtOAc fraction decreased in a dose dependent manner compared with the allopurinol control group, although those of fermented fractions were significantly lower than those of non-fermented fractions. This study suggests that fermented Smilax china L. leaf extracts may regulate the XO and AO inhibitory activities and antihyperuricemic effect due to aglycone components from glycoside form flavonoids by fermentation of A. oryzae.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.6-11
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• 2007

[ $\beta$ ]-Fructofuranosidases, a family 32 of glycoside hydrolases (GH32), share three conserved domains including the W(L/M)(C/N)DP(Q/N), FRDPK, and ECP(D/G) motifs. The functional role of the conserved acidic residues within three domains of levan fructotransferase, one of the $\beta-fructofuranosidases$, from Microbacterium sp. AL-210 was studied by site-directed mutagenesis. Each mutant was overexpressed in E. coli BL21(DE3) and purified by using Hi-Trap chelating affinity chromatography and fast performance liquid chromatography. Substitution of Asp-63 by Ala, Asp-195 by Asn, and Glu-245 by Ala and Asp decreased the enzyme activity by approximately 100-fold compared to the wild-type enzyme. This result indicates that three acidic residues Asp-63, Asp-195, and Glu-245 play a major role in catalysis. Since the three acidic residues are present in a conserved position in inulinase, levanase, levanfructotransferase, and invertase, they are likely to have a common functional role as nucleophile, transition state stabilizer, and general acid in $\beta-fructofuranosidases$.