• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.247-252
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• 1996

$\beta$-Amylase was purified from sweet potato by acetone fractlonatlon, Sephadex A-50 ion exchange chromatography and Sepgadex G-200 gel chromatographyl The higher enzyme concentration was, the higher heat stability of enzyme became. After 1 hour 30 minute. At 6$0^{\circ}C$ in pH 5, enzyme under concentration of 30$\mu$l/ml lost its activity completely and over the concentration of 100$\mu$g/ml remained 25% of activity. The enzyme was stabilized at range of pH 4~10 and pH stability was increased by glycerol. Five moles of NaCl inhibited completely of the enzyme activity. SDS of 0.05% inhibited the enzyme completely after 12 hours at 37$^{\circ}C$ in pH5. One mole guanidine-HCl and 8M urea inhibited the entire enzyme after 13 hours at 37$^{\circ}C$ in pH 5.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.123-127
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• 1969

The studies were conducted to know the relationship between $\beta$-amlyase activities and hardiness for the germinated seedlings of, winter wheat varieties which were classified with eye estimated cold resistance in field as, susceptible, moderate and resistant. These varieties were tested in continued five days from germination in four replicated split plot design. For the measurement of $\beta$-amylase, improved A. K. Balls method (2) was employed. Result obtained will be summarized as follows. 1. Tested varieties showed highly significant differences in $\beta$-amylase activity, while no differences were obtained between dates after germination. 2. Winter hardy varieties, Yukseung ＃3, Chin Kwang and Suwon＃85 showed higher amylase activities than the moderate hardy varieties, Jukdalma, Kangdosinryuk and Norin ＃4, while lower activities were measured in susceptible varieties, Norin ＃6, Kangdo and Norin＃12. 3. With measurement of $\beta$-amylase activity, rurther detail classification to cold resistance is seemed available than eye-estimating in the field condition. 4. In accordance with testing dates, amylase activities were not so clear on 1st, 2nd, 4th and 5th days from germination, while clear differences were found on 3rd day from germination. 5. Amylase activity obtained on 3rd day after germination is considered easy and effective method to estimate cold resistance of wheat varieties with a classification standard.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.328-333
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• 2015

A Myagropsis myagroides (Mm) methanol extract showed α-amylase inhibitory activity of 13% at a concentration of 5 mg/ml. Results showed that the hexane fraction from the Mm methanol extract exhibited α-amylase inhibitory activity with an IC₅₀ value of 4.24 mg/ml. The hexane fraction was separated using silica-gel column chromatography, and six subfractions were obtained. The fraction eluted with CHCl₃:MeOH = 50:1 showed the highest α-amylase inhibitory activity with an IC₅₀ value of 0.72 mg/ml. This fraction was purified using Sephadex LH-20 column chromatography and an octadecyl silica (ODS) Sepak cartridge, obtaining seven subfractions. Fraction (Fr.) 4 also showed a strong α-amylase inhibitory activity with an IC₅₀ value of 0.75 mg/ml. Fr. 4 was purified by Sephadex LH-20 column chromatography and ODS Sepak cartridge, obtaining six subfractions. Fr. 4-2 was identified as sargachromanol I with an IC₅₀ value of 0.40 mg/ml, and the inhibition pattern analyzed from Lineweaver-Burk plots revealed it to be an uncompetitive inhibitor. These results suggest that Mm has potential as a natural antidiabetes agent.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.367-375
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• 1998

The physicochemical properties of the $\alpha$-amylase inhibitors from black bean and naked barley is Korea were investigated. Preincubation time for maximum inhibition was 30min and no activity change was seen after that time. Optimum pH of the $\alpha$-amylase inhibitors from the black bean and naked barley was pH 7.0 and the inhibitory activities were stable in the range of pH 6.0~8.0 in both phosphate and Tris-HCI buffer solutions. Both inhibitors maintained more than 50% of activity after incubation for 17 min at 7$0^{\circ}C$. The inhibitors from the black bean and naked barley maintained more than 50% of activities after treatment for 40 min and 30 min with pepsin, and 30 min and 50 min with trypsin, respectively. Both inhibitors functioned via a noncompetitive mechanism and were active against porcine pancreatic and human salivary $\alpha$-amylases. The activities of both inhibitors were linear for the ionic stength ranging from 0 to 0.9. The addition of 70 mM maltose to the reaction mixture caused a maximum increase in the relative activities of both inhibitors, but it did not affect the dissociation of the EI complex. The activities of both inhibitors were significantly enhanced by adding 1mM of K+ or Mg2+.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.308-315
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• 2011

We investigated ${\alpha}$-amylase, ${\alpha}$-glucosidase and lipase inhibitory activity of extracts collected from wild plants in Gangwon-do. 90 wild plants were collected and their water and ethanol extracts were obtained. Results of measuring ${\alpha}$-amylase inhibitory activity indicated more than 80% of activity inhibition in 10 mg/mL concentration for ethanol extracts of three plants and water extracts of two plants. For ${\alpha}$-glucosidase inhibitory activity, ethanol extracts of thirteen plants and water extracts of three plants showed more than 80% of activity inhibition in 10 mg/mL concentration. In the experiment of inhibiting lipase activity, ethanol extracts of seven plants and water extracts of one plants showed above 80% of activity inhibition in 10 mg/mL concentration. These results suggest that the selected extracts could be potentially used as a resource of bioactive materials for health functional foods.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.762-767
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• 1995

The ${\alpha}-Amylase$ inhibitor from black bean(Phaseolus vulgaris) was purified to homogeneity using 70% saturated ammonium sulfate, DEAF-cellulose, Concanavalin-A sepharose chromatography and gel filtration with Superose 6. The purified α-amylase inhibitor showed a single band of 25 KD in molecular weight on the SDS-PAGE. The specific activity of the inhibitor was 544.0 units/mg and the purity was enhanced about 18-fold. The amino acids of ${\alpha}-Amylase$ inhibitor from black bean was mainly glutamic acid, aspartic acid and lysine. The inhibitor was glycoproteins and its carbohydrate contents was 3.2%.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.412-422
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• 2019

The present study reports the morphological and molecular characterization of the fungal strain, CMSS06 and evaluates its raw starch hydrolyzing ability in four different agricultural substrates (rice bran, banana peel, cassava tubers, and coconut water). The potential use of each agricultural substrate to replace the expensive fermentation media was evaluated with six different fermentation media: rice bran (RB), banana peel (BP), cassava starch (CS), cassava in coconut water (CSCW), cassava in modified coconut water (CMCW), and pure Coconut water (CW). The fungal strain CMSS06 was identified as Thielaviopsis ethacetica by the analysis of the ITS sequences. The T. ethacetica alpha amylase enzyme exhibited maximum alpha amylase activity at 72 h, pH 7.0, and $40^{\circ}C$ on soluble starch. This species resulted in the highest enzyme activity (mU/ml) of 26.06, 10.89, 58.82, 14.2, and 54.67 with the RB, BP, CS, CSCW, and CMCW fermentation media, respectively. The results indicate that CS can be used as a carbon substrate and CMCW can be used to accelerate the fermentation by T. ethacetica. The enzyme was partially purified by 40-60% ammonium sulphate fraction, and it showed total enzyme activity, total protein content, specific activity, purification fold, and a recovery of 2400 mU, 30 mg, 80 mU/mg, 2.7, and 71.1%, respectively. The molecular mass of the T. ethacetica alpha amylase was estimated on SDS-PAGE, and two bands around 50 kDa and 70 kDa were identified. The present study implies that T. ethacetica can produce alpha amylase, and it can be used to hydrolyze raw starch during the fermentation processes.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.359-365
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• 2015

The purpose of this study was to investigate the contents of sugars and ${\alpha}$-amylase and ${\beta}$-amylase activities in 98 specimen with enzyme foods and enzyme-shaped foods (the other processed foods, beverage bases, fermented drinks, liquid teas). The ${\alpha}$-amylase activity in enzyme foods and the other processed foods were ranged 4.9~53,854.6 U/g and 2.9~1,182.7 U/g, respectively, there was a big difference in the same type. The ${\alpha}$-amylase activity of the fermented products (beverage bases, fermented drinks, liquid teas) were ranged 0.1~1.7 U/g. The average of ${\beta}$-amylase activity in enzyme foods, the other processed foods, the fermented products were found 126.0 U/g, 5.6 U/g and 10.5 U/g, respectively, enzyme-shaped foods were a lot lower than enzyme foods. Total contents of sugars were average 22.4 g/100 g in enzyme foods, 14.8 g/100 g in the other processed foods, 46.9 g/100 g in beverage bases, 41.1 g/100 g in fermented drinks, 39.5 g/100 g in liquid teas, total contents of sugars appeared high amount in the fermented products. Correlations between ${\alpha}$-amylase activity and lactose content was statistically significant in enzyme foods (r = 0.644) and it was strong in the other processed foods (r = 0.903). Correlations between ${\beta}$-amylase activity and lactose content was statistically significant in enzyme foods (r = 0.648) and it was strong in the other processed foods (r = 0.757). There was a significant relationship between ${\alpha}$-amylase and ${\beta}$-amylase activities in enzyme foods and the other processed foods (r = 0.869, r = 0.760). That is, it was found that also the proportional relationship established among the ${\alpha}$-amylase activity, ${\beta}$-amylase activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.42-47
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• 2008

Prevention of postprandial hyperglycemia is important, as it is implicated in the development of macro- and microvascular complications associated with diabetes. An inhibitor of ${\alpha}$-amylase which acts in the first step of carbohydrate digestion, is expected to be a suppressor of postprandial hyperglycemia. This study investigated the porcine pancreatic ${\alpha}$-amylase inhibitory activity of the extracts from buckwheat (Fagopyrum esculentum) flower, leaf, stem and grain. Flower, leaf, stem and grain of buckwheat were extracted by water and ethanol (40%, 70%, 100%), respectively. Flower and leaf extracts were more effective ${\alpha}$-amylase inhibitors than stem and grain extracts in all tested solutions. Ethanol extracts were more effective than water extracts or powders on the ${\alpha}$-amylase inhibitory activities. At concentrations of $0.5%{\sim}10%$ (w/w, starch basis), the flower extracts of 40%, 70% and 100% ethanol lowered the enzyme activity by about 90% and the results were similar to the values of acarbose. At the same concentrations, the leaf extracts of 100% ethanol lowered the enzyme activity by about 90%. These results suggest that buckwheat flower and leaf ethanol extracts may delay carbohydrate digestion and lower postprandial hyperglycemia.