• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.399-405
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• 1999

Intergeneric hybrids between Saccharomyccopsis fiburigera KCTC 7393 and Saccharomyces cerevisiae KCTC 7049 (tyr-, ura-) were obtained by nuclear transfer technique. Nuclei isolated from the wild type S. fiburigera strain were transfered into auxotrophic S. cerevisiae mutants and new strains showing an increased starch degrading capability were selected. Maximum production of protoplasts was obtained from the treatment with 0.1 % Novozym 234 at $30^{\circ}C$ for 90 min, and most effective osmotic stabilizer for the isolation of protoplasts was 0.6 M KCl at pH 5.8. The frequency of protoplast regeneration was 14.64% under the conditions. Genectic stability, conidial size, DNA content, and nuclear stain suggested that the fusants were aneuploidy. The specific activity of ${\alpha}-amylase$ was observed to increase about $1.2{\sim}1.9$ folds.

• Natural Product Sciences
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• v.13 no.4
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• pp.311-316
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• 2007

In this study, the twenty-four ethyl acetate extracts of twenty-two medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for ${\alpha}$-amylase and protein tyrosine phosphatase 1B (PTP1B) enzymes inhibitory activity in vitro. The results indicated that, twelve materials (50.0%) showed moderate to strong inhibitory activity in ${\alpha}$-amylase inhibitory activity with $IC_{50}$ values ranging from 2.5 to $48.8{\mu}g/mL$; meanwhile, ten extracts (41.6%) could demonstrate PTP1B activity with $IC_{50}$ values less than $30.5{\mu}g/mL$. Some plants presented interesting activities against both of ${\alpha}$-amylase and PTP1B enzymes such as Catharanthus roseus, Carthamus tinctorius, Momordica charantia, Gynostemma pentaphyllum, Glycyrrhiza glabra, Smilax glabra, Psidium guajava (leave), and Rehmannia glutinosa. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.765-769
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• 2001

Starches of flavored glutinous rice were analyzed by using scanning electron microscope (SEM) and differential scanning calorimetry (DSC) and tested on the starch granule susceptibility to 15% H$_2$SO$_4$, glucoamylase and $\alpha$-amylase. The shape of starch granules form flavored glutinous rice varieties was polygonal and the size was 4~6 $\mu$m in diameter. According to DSC, glutinous rice starch showed onset temperature (T$_{o}$) range 59.8~62.5$^{\circ}C$ and KR92021-B-B-42-3-B and KR92021-B-B-165-1-B showed higher enthalpy ($\Delta$H) on gelatinization than others. The starches from KR92021-B-B-5-2-B and KR92021-B-B-42-3-B showed lower hydrolysis rate using 15% H$_2$SO$_4$ than KR92021-B-B-165-1-B. KR92021-B-B-5-2-B showed higher degree of hydrolysis of glucoamylase and $\alpha$-amylase than the others.

• Applied Biological Chemistry
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• v.21 no.2
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• pp.84-102
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• 1978

Barley embryoless half seeds were incubated in medium containing $10{\mu}M$ GA. Time course activity changes of ${\alpha}-amylase$ were studied in extract and medium seperately by the addition of $0.1{\mu}M,\;5{\mu}M,\;and\;10{\mu}M$ ABA in midcourse incubation of 10 hours after GA treatment. MAK profiles of nucleic acids in embryoless half seeds were compared either with $10{\mu}M$ GA treatment or concomitant treatment with $10{\mu}M$ GA and $10{\mu}M$ ABA after 10 hours incubation, Time course changes of weight increase, chlorophyll, protein and RNA consent in addition to RNase activity were studied in the presence of $10{\mu}M$ GA or $10{\mu}M$ ABA in barley coleoptile sections. After 20 hours incubation in the presence of plant hormones, MAK profiles of nucleic acids and reactive distribution of polysome and monosome were investigated. The above results were summarized as follows. 1) The production of ${\alpha}-amylase$ by treatment with GA alone increased at a linear rate in the incubation period and the active secretion of ${\alpha}-amylase$ began from 18 hours incubation in embryoless half seeds. 2) On the contrary to the partial inhibition by addition of $0.1{\mu}M$ ABA, the production of ${\alpha}-amylase$ was completely inhibited by both $5{\mu}M$ and $10{\mu}M$ ABA within 4 hours. Regardless of concentration of GA, the addition of $5{\mu}M$ ABA in midcourse completely inhibited the production of ${\alpha}-amylase$ 3) ABA treatment gave no effect on the secretion of ${\alpha}-amylase$. 4) There were no differences in RNA fractions between GA treatment and concomitant treatment with GA and ABA in the barlye embryoless half seeds. 5) While GA treatment increased the r-RNA fraction, ABA treatment decreased it and increased the s-RNA fraction in the coleoptile sections. 6) GA treatment increased RNA-DNA fraction best ABA treatment decreased it in the coleoptile sections. 7) While GA treatment suppressed RNase activity, ABA treatment increased it in the coleoptile sections. 8) GA treatment gave no great effect on the total RNA but ABA treatment remarkably diminished it in the coleoptile sections. 9) While GA treatment increased the growth and chlorophyll content, ABA treatment decreased them in the coleoptile sections. 10) GA treatment increased the protein synthesis and polysome formation but ABA treatment decreased them in the coleoptile sections. 11) The inhibition effect of ABA on polysome formation seemed to be resulted from the inhibition of r-RNA synthesis by ABA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.164-170
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• 1985

Yellowish modified wool, dithiocarbamate(DTC) wool, was synthesized by partial hydrolysis in 0.2 N-NaOH reacting with carbon disulfide to use as ${\alpha}-amylase$ immobilization matrix. ${\alpha}-amylase$ was immobilized reacting with sulfide group of DTC-wool by covalent binding within 1 hour. 0.5 gram of this preparation, $DTC-wool-{\alpha}-amylase$, contained 150 ug of enzyme protein and its specific activity was about 90% of the native one. General properties of $DTC-wool-{\alpha}-amylase$ were a little different from optimum temperature, optimum pH, heat stability, kinetic constants and activation energy. An apparent Michaelis constant and maximum velocity of $DTC-wool-{\alpha}-amylase$ were 5.56 mg/ml and 0.37 mg/ml. $min^{-1}$ respectively, while activation energy was 16.6 kcal/mole.

• Food Science and Preservation
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• v.21 no.2
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• pp.254-263
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• 2014

This study was carried out to analyze the effects of water and 70% ethanol extract on the antioxidative and antidiabetic activities of Smilax china L., a vine shrub belonging to the lily family. The activities of the extracts were measured based on the total phenolic and flavonoid contents and through on the results of the antioxidant tests, such as the electron-donating ability, ABTs radical scavenging activities, SOD-like activity, xanthine oxidase inhibition effect, antioxidant protection factor (PF), TBARs content and ACE inhibition activity, and ${\alpha}$-glucosidase, and ${\alpha}$-amylase inhibition activity. The resulting total phenolic and flavonoid contents of the 70% ethanol extract from S. china L. were greater than those of the water extract from S. china L. With regard to the results of the antioxidant tests, such as the electron-donating ability, ABTs radical scavenging activity, SOD-like activity, xanthine oxidase inhibition effect, antioxidant protection factor (PF), and TBARs content, those from the 70% ethanol extract from S. china L. were greater than those from the water extract from S. china L. Also, with regard to the ACE inhibition effect and ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibition, those from the 70% ethanol extract from S. china L. were greater than those from the water extract from S. china L. All these findings show that the 70% ethanol extract from S. china L. has greater antioxidative and antidiabetic effects and can be used as a preventive agent for oxidation and diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.405-409
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• 2008

This study was performed to investigate the physiological activities of Viola mandshurica. Antioxidant activity was evaluated by measuring total phenolic contents, reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-di-2-ethyl-benzthiazoline sulphonate (ABTS) radical scavenging activity while anti-diabetic activity was measured by inhibition activities on ${\alpha}$-amylase and ${\alpha}$-glucosidase. V. mandshurica extracts were prepared by extracting with four different solvents (methanol, ethanol, acetone, and water). The methanol extract showed the highest total phenol content (34.49 mg/g gallic acid equivalents) among the extracts. The water extract showed the highest reducing power (0.454) at the concentration of $1,000{\mu}g$/mL. The acetone extract showed the most potent radical scavenging activity. DPPH and ABTS radical scavenging activity of the acetone extract at the concentration of $1,000{\mu}g$/mL were 21.13% and 43.53%, respectively. The inhibitory activity of acetone extracts against ${\alpha}$-amylase and ${\alpha}$-glucosidase showed more than 100% at the concentration of $1,000{\mu}g$/mL. The results indicate that V. mandshurica might have potential antioxidant and anti-diabetic activities.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.622-628
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• 2014

The aim of this work is to evaluate the potential of oriental melon (Cucumis melo L. var. makuwa Makino) seeds for the management of type 2 diabetes by controlling glucose absorption. The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effects of the hexane extracts from oriental melon seeds were investigated. A bioassay-guided fractionation technique was used to elucidate the principal active components. The results show that the hexane extract from oriental melon seeds exhibited high inhibitory activities against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The hexane extract was further fractionated into four sub-fractions. Among them, the sub-fraction F-1 exhibited the most potent anti-diabetic effect. The active components were isolated and identified by gas chromatography/mass spectroscopy (GC-MS). Free fatty acids showed significant hypoglycemic activity (p < 0.001) and fatty acid composition influenced enzyme inhibitory activities. These results suggest that oriental melon seeds could be used to prevent type 2 diabetes.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.333-338
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• 2013

Enzymatic activity in germinated cereal grains is important for the saccharification of starch materials. This study was conducted to investigate the amylolytic activities of germinating brown rice and black rice that have different amylose contents. Brown rice and black rice were steeped at room temperature for 24 h and germinated at 20 and $30^{\circ}C$ for 1, 2, and 3 days. ${\alpha}$- and ${\beta}$-Amylase activities in normal brown rice increased very slightly during the 3-day germination period, but the enzymatic activities were slightly higher in low-amylose (waxy type) brown rice. Diastatic power (DP), a measure of starch-saccharifying enzyme, was higher in the germinating brown rice with low amylose than in those with normal amylose content. ${\alpha}$- and ${\beta}$-Amylase activities in black rice increased gradually during germination, and DP of low-amylose black rice appeared to be higher than that of normal brown rice. Amylase activities in brown rice and black rice germinated at $30^{\circ}C$ were higher than those germinated at $20^{\circ}C$. Compared to brown rice, the overall amylolytic activity of germinated black rice was observed to be higher than that of brown rice.

• KSBB Journal
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• v.23 no.5
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• pp.419-424
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• 2008

In this study, we examined the anti-diabetic activity in vitro by the crude extracts of Tetragonia tetragonioides which has been known to superior plants for the traditional prevention and treatment of stomach-related diseases. $\alpha$-Amylase and $\alpha$-glucosidase, the principal enzymes involved in the metabolism of carbohydrates, and aldose reductase, the key enzyme of the polyol pathway, have been shown to play the important roles in the complications associated with diabetes. A hexane (HX) fraction of T. tetragonioides were shown to inhibit more than 50% of salivary and pancreatin $\alpha$-amylase activity at concentration of 2.882 mg/mL and 2.043 mg/mL, respectively. In addition, the HX and ethylacetate (EA) fraction showed the highest inhibitory activity on yeast $\alpha$-glucosidase at values of $IC_{50}$ of 0.723 mg/mL and 1.356 mg/mL respectively. The HX, dichloromethane (DCM) and EA fraction showed more higher inhibitory activity on yeast $\alpha$-glucosidase than commercial agent such as 1-deoxynorjirimycin and acarbose. Also, the aldose reductase from human muscle cell had been inhibited strongly by the DCM fraction and HX fraction at 51.95% and 47.22% at a concentration of 1 mg/mL, respectively. Our study, for the first time, revealed the anti-diabetic potential of T. tetragonioides and this study could be used to develop medicinal preparations or nutraceutical and functional foods for diabetes and related symptoms.