• Applied Biological Chemistry
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• v.39 no.4
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• pp.293-296
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• 1996

The present study was carried out to investigate the effect of Ni on germination, cell elongation, ${\alpha}-amylase$ activity, contents of chlorophyll and protein in radish were determined in the water culture. As the concentration of Ni was increased in the water culture, germination of radish was 55% by Ni 10 mg/kg and 30% by Ni 20 mg/kg. The ratio of cell elongation injury was 50%, by two days after Ni 20 mg/kg treatment. The injury ratio of ${\alpha}-amylase$ activity was 45% in the same condition and as the time goes on, inhibition of ${\alpha}-amylase$ activity were slightly decreased. Contents of chlorophyll a and b were decreased two days after treatment and chlorophyll a was more inhibited than chlorophyll b. Also changes of the protein contents was slightly decreased. Activity of ${\alpha}-amylase$ was decreased at germination stage, contents of chlorophyll a and b were decreased at growing stage.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.302-307
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• 2008

Novel amylase inhibitors were synthesized via transglycosylation by Thermotoga maritima glucosidase (TMG). TMG hydrolyzes acarbose, acarviosine-glucose, and maltooligosaccharide by releasing $^{14}C$-labeled glucose from the reducing end of each molecule. When TMG was incubated with acarviosine-glucose (the donor) and glucose (the acceptor), two major transfer products, compounds 1 and 2, were formed via transglycosylation. The structures of the transfer products were determined using thin-layer chromatography (TLC), high-performance ion chromatography (HPIC), and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopy. The results indicate that acarviosine was transferred to glucose at either C-6, to give a $\alpha-(1{\rightarrow}6$) glycosidic linkage, or at C-3, to produce an $\alpha-(1{\rightarrow}3$) glycosidic linkage. The transfer products showed a mixed-type inhibition against porcine pancreatic $\alpha$-amylase; therefore, they may be useful not only as inhibitors but also as acarbose transition-state analogs to study the mechanism of amylase inhibition.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.159-168
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• 1998

Effect of plant growth regulators and end-product on the enzyme activities in cotyledons of Vigna angularis during germination was investigated by measuring the changes of $\alpha-amylase$ activities in attached and detached cotyledons applied growth regulators and sugars. The higher levels of $\alpha-amylase$ in detached cotyledons than those in cotyledons attached to the embryonic axis were due to both faster synthesis and slower degradation of the enzyme in the detached cotyledons than in the attached cotyledons. Levels of $\alpha-amylase$ activity were reduced by high concentrations of glucose and sucrose, and it is suggested that this effect was caused mostly by osmotic stress and partly by end-product repression. In detached cotyledons exogenously supplied $GA_3,$ IAA, kinetin, or their combinations has a small promotive effect on the developmental patterns of $\alpha-amylase$ activity ABA and uniconazole both prevented the synthesis of $\alpha-amylase$. Glucose inhibition of enzyme activity was partly reversed by the application of $GA_3,$ and CAMP. $GA_3,$ and cAMP seemed to act through a similar mechanism. The addition of inhibitors of protein and RNA synthesis largely prevented the increase of enzyme activity in the presence or absence of exogenous $GA_3,$. The pretreatment experiments with canavanine indicated that the earlier the time of addition was, the lower the amylase activity was.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.2
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• pp.69-75
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• 1987

Nicotine, the main alkaloid of tobacco, showed different effect according to the enzyme. Among investigated enzymes, protease was inactivated remarkably by nicotine and the mode of inhibition was examined. $\alpha$-amylase and $\beta$-amylase were not affected, and cellulase and glucoamylase were inactivated partially when the concentration of it was over 1.0% , but protease was inhibited powerfully by nicotine The inhibition of protease by nicotine was performed almost in the initial stage of reaction, and was not so much affected by temperature, and was reversible. The inhibition type of protease by nicotine appeared as a Mixed-type inhibition.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.7-11
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• 1985

In order to investigate the biological activity of ginseng saponins, the effects of ginseng saponins on the reaction catalyzed by bacterial a-amylase were studied and the results obtained were summerized as follows. Bacterial ${\alpha}$-amylase activity was increased by the addition of protopanaxadiol (diol), protopanaxatriol (triol) and total saponin. Preincubation of ${\alpha}$-amylase with diol saponin at $40^{\circ}C$ for 3 min increased ${\alpha}$-amylase activity to the degree of 120%. In the protective effect on the heat denaturation of the enzyme, triol saponin protected the heat denaturation for 5 min at $60^{\circ}C$, but diol saponin accelerated the heat denaturation. The hydrolyzates of diol and triol saponin increased the enzyme activity more than the intact diol and triol saponin. In the catalysis system of bacterial ${\alpha}$-amylase, the addition of diol and triol saponin reduced the substrate inhibition in the presence of high concentration of the substrate.

• Food Science and Preservation
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• v.18 no.6
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• pp.923-929
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• 2011

For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb mixture prepared through traditional antidiabetic prescription, the study analyzed the existence of insulin-similar components and examined ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity. As a result of arranging the medicinal herb mixture extracts over the 3T3-L1 fibroblast in the concentration of $10{\mu}g/mL$, which confirmed that it included much of insulin sensitizer components as 151.7% in the differentiation of 3T3-L1 fibroblast. The inhibition activity against ${\alpha}$-amylase of the medicinal herb mixture extracts as hypoglycemic agent were 38.4, 31.5 and 16.6% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase of the medicinal herb mixture extracts were 81.3, 35.8 and 26.7% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase in the ethyl acetate fractions of the water and 80% ethanol extracts were 66.9% and 55.1%, respectively, the highest levels in the various solvent extracts.

• YAKHAK HOEJI
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• v.35 no.1
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• pp.30-37
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• 1991

Streptomyces actuosus DMCJ-49 and Streptomyces minoensis DMCJ-144 produce the .alpha.-amylase inhibitor. Inerspecific protoplast fusion technique was used to increase the productivity of .alpha.-amylase inhibitor. Four auxotrophic mutants were obtained respectively from two strains by N-methyl-N'-nitor-N-nitrosoguanidine(3mg/ml) treatment. The optimum conditions for the protoplast formation of Streptomyces actuosus DMCJ-49 ade was as follows; 1.2% w/v of glycine, 3mg/ml of lysozyme, and 30 min of lysozyme treatment followed by 36 hr. incubation in the protop-last formation medium. In case of DMCJ-144-his those were 1.2%w/v, 3 mg/ml, 30 minutes and 60 hours, respectively. Regeneration was accomplished with hypertonic soft agar medium that contained 0.4M sucrose, 20mM CaCl$_2$, 50 mM MgCl$_2$ and low levels of phosphate. Fusion of protoplasts carrying different auxotrophic markers was achieved by treatment with polyethylene glycol. The optimum concentration of polyethylene glycol 1450 for the production of recombinants was 40%w/v. When the protoplasts was treated with 40% polyethylene glycol for 30 minutes, the frequency of recombinants was 6.5$\times$$10^{-3}$ and the $\alpha$-amylase inhibition activity of $ade^-his^-$ No. 4, which is the fusant with the most improved activity increased from 33 to 125 I.U./ml.

• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.128-131
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• 2007

This study was carried out to investigate inhibitory effect of extracts from Artemisia capillaris Thumb. on maltase, sucrase, ${\alpha}-amylase$, nonspecific ${\alpha}-glucosidase$, and postprandial hyperglycemia. Methanol extract and organic solvent (n-hexane, ethyl acetate, butanol, aqueous) fractions from the medicinal herb were determined for the inhibitory activities against maltase, sucrase and ${\alpha}-amylase$. The methanol extract from A. capillaris strongly inhibited maltase (57%) and ${\alpha}-glucosidase$ (72%) at the concentration of 100 ${\mu}g/m{\ell}$. Among the four fractions (n-hexane, ethyl acetate, butanol, aqueous) examined, the butanol fraction from A. capillaris showed potent inhibitory effects on maltase (73%), sucrase (33%), and ${\alpha}-amylase$ (75%) at the concentration of 100 ${\mu}g/m{\ell}$. The butanol fraction from Artemisia capillaris also exhibited significant reductions (20%) of blood glucose elevation in mice loaded with maltose. These results suggest that the extract from Artemisia capillaris can be used as a new nutraceutical for inhibition on postprandial hyperglycemia

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.70-73
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• 2007

Antioxidant and anti-diabetic activities of acorn were evaluated by its potential for scavenging stable DPPH free radical, inhibition of lipid peroxidation, reducing power, and inhibiton of ${\alpha}-glucosidase\;and\;{\alpha}-amylase$. The water extract of acorn exhibited strong antioxidant and antidiabetic related activities in the tested model systems. Solvent fractionation of the water extract revealed that the water fraction and the EtOAc fraction had strong antioxidant activity, and inhibitory activity on ${\alpha}-glucosidase\;and\;{\alpha}-amylase$. The water fraction exhibited higher DPPH radical scavenging activity ($EC_{50}=7.19{\mu}g/mL$) than that of ${\alpha}-tocopherol\;(EC_{50}=7.59{\mu}g/mL)$. It is considered that water extract of acorn has the potential for natural antioxidant and anti-diabetic products.

• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.374-382
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• 2013

The objective of this study was determined to evaluate ${\alpha}$-amylase, ${\alpha}$-glucosidase, pancreatic lipase inhibition in vitro and DPPH radical scavenging activity of the several Korean resources plants. The ${\alpha}$-amylase inhibitory activity of Salicornia herbacea, Erythronium japonicum (flower) and Phragmites communis (root) in water extract showed relatively high 62.8%, 66.5% and 69.3%, respectively. The ${\alpha}$-amylase inhibitory activity of Citrus junos (pericarp) and Cornus officinalis in methanol extract was found to have an effect with 32.8% in Citrus junos (pericarp) and 60.9% in Cornus officinalis. Corylopsis coreana in both water and methanol extract had the highest ${\alpha}$-glucosidase inhibitory activity of 81.7% and 89.5%, while the extract of Portulaca oleracea, Ficus carica and Citrus junos was not measured ${\alpha}$-glucosidase inhibitory activity at given experiment concentration. Depending on the extraction solvent and the plant species, it was observed that there was a significant difference in ${\alpha}$-glucosidase inhibitory activity. The pancreatic lipase inhibitory activity showed relatively higher in the methanol extract than water extract except pericarp of Citrus junos. The DPPH radical scavenging activity of selected plants was much difference between measured plant species, and showed that the increase was proportional to the concentration. These results suggested that selected plants had the potent biological activity on carbohydrate, lipid Inhibitory activity and antioxidant activity, therefore these plant resources could be a good materials to develop medicinal preparations, nutraceuticals or health functional foods for diabetes or obesity.