• Journal of Nutrition and Health
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• v.53 no.3
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• pp.244-254
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• 2020

Purpose: Ixeris strigosa (IS) is a perennial plant that commonly grows in meadows. The leaves and roots of IS have been used in medicine as a sedative. This study evaluated the antioxidant and carbohydrate-digestive-enzyme inhibitory effects of IS to determine its potential as an essential antioxidant and glycemic inhibitor for type 2 diabetics. Methods: The antioxidative and α-amylase and α-glucosidase inhibitory activities were examined using the water extracts (ISW), ethanol extracts (ISE), and solvent fractions from IS. The antioxidative activities were measured using in vitro methods by measuring the 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity. Results: Investigations of the total polyphenol, flavonoid content, in vitro antioxidant activity, and α-amylase and α-glucosidase inhibitory activities of the IS extract showed that the ISE had higher total phenolic and flavonoid contents than the ISW, as well as high antioxidant activity. The ethanolic extracts of IS (70%) had an α-amylase inhibitory activity of 78.55%. The ethyl acetate fraction (90.56%) showed higher α-glucosidase inhibitory activity than the positive control, acarbose (83.01%). Conclusion: Among the ISE fractions, the ethyl acetate and butanol fractions showed the best digestive enzyme inhibitory activity. Moreover, the antioxidant activity of the extract and the carbohydrate, α-amylase, and α-glucosidase inhibitory effects showed a stronger correlation with the total phenol and flavonoid contents compared to the ISW. As a result, the antioxidant and digestive enzyme inhibitory activities of high ISE are due to the phenolic compounds, particularly the flavonoid compounds. Therefore, ethyl acetate and butanol fractions of the 70% ethanol extract are excellent anti-diabetic functional materials.

• Korean Journal of Microbiology
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• v.26 no.2
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• pp.73-81
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• 1988

$\alpha$-Amylase (EC.3.2.1.1) of Neurospora crassa (ATCC9279) was cloned in E. coli HB101 using shotgun method, and the enzymes isolated from both N. crassa and E. coli were compared. Chromosomal DNA isolated from the spores of N. crassa was partially digested with PstI restriction endonuclease and rejoined to pBR322 which had been digested with the same enzyme. The resulting recombinant DNA were introduced into E. coli HB101 which had competancy by treating with $CaCl_{2}$. As the result, about 8000 colonies which showed tetracycline resistance were selected and two of the colonies which had 13.5Kb recombinant plasmid exhibit starch degrading activity on starch-containing plate when treated with D-cycloserine. $\alpha$-Amylases from both N.crassa and E. coli were isolated by using ammonium sulfate precipitation, DEAE-cellulose ion exchange column chromatography and Bio-Gel P150 gel foltration column. As the result, about 81.3 fold and 5.6 fold purifications in specific activities were obtained respectively, and specific activities of the gel filtrates were 6.1u/mg and 85u/mg respectively. The properties of both enzymes were compared and they showed quite the similar patterns in optimal temperature, optimal pH and had same molecular weight about 100,000 daltons on gel filtration method. Optimal temperatures for both enzymes were $70^{\circ}C$ and optimal pH were about 6 and 10.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.632-638
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• 2006

Characteristics of sweet (sugary, su) and super sweet (shrunken-2, sh2) corn seeds shelled by different threshing methods at different moisture content status were studied. Hybrid seeds of a su (Early Sunglow ${\times}$ Golden Cross Bantam 70, GCB 70) and a sh2 (Xtrasweet 82 ${\times}$Fortune) were dried to moisture content of 12, 15, 18, and 21%. Hand shelling did not give any mechanical damages to seeds, while an electrical corn thresher gave some visible mechanical damages. The emergence rate of hand shelled seeds was higher than that of machine shelled seeds by $6{\sim}14%$ for a su and by $9{\sim}18%$ for a sh2 hybrid depending on seed moisture contents in cold test. The optimum seed moisture content to reduce mechanical threshing damages and to improve seed quality was 15% for su and 12% for sh2 hybrid seeds. At the optimum seed moisture contents, germination rate at $25^{\circ}C$, emergence rate in the cold test and ${\alpha}-amylase$ activity were highest, while the percentage of damaged seeds and leakage of total sugars and electrolytes in soaking water were minimized.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.251-256
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• 2008

Eoyukjang is a traditional sauce-type of Korean food that is similar to a soybean sauce made from fermented soybeans, and it is produced from a fermented mixture of sea foods, meats, and meju (soybean paste). This study examined periodical changes in the enzymatic activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, protease, lipase, and lipoxygenase within the culture broth and solids of eoyukjang during 1 year of fermentation. The eoyukjang solids had 234-532% higher protein content than the culture broth. The specific activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease increased in both the culture broth and solids. Particularly, in the culture broth, ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease activities rapidly increased (3- to 8-fold) until 10 months of fermentation, and then drastically decreased. However, the activities of lipase and lipoxygenase in both the culture broth and solids were less than 0.05 unit/mg of protein, respectively, throughout fermentation; thus, their activity levels were low and changed little over the 12 months. Overall, while the solids had higher protein content than the culture broth, the broth had greater enzyme activity levels during eoyukjang preparation.

• 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.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.15-24
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• 1980

[${\alpha}$]-Amylase catalyses the hydrolysis of starch, glycogen, and related poly- and oligosac-charide by random cleavage of ${\alpha}$-D-(l-4) glucan linkage. In man large amounts of amylase are secreted into the digestive tract by the salivary and exocrine pancreatic gland, minimal amount being produced also in other tissues. It has been known that ${\alpha}$-amylase exists in multiple molecular forms, isoenzyme which can be separated from each other because of difference in their physicochemical properties. By using various methods, several groups of investigator have separated the many isoenzyme in serum, saliva and pancreatic juice. Furthermore, changes of the normal serum isoenzyme pattern is diagnostically useful even when the total serum enzyme activity is noninformative, such as the clinical use of isoenzyme of serum lactate dehydrogenase. Procarboxypeptidase-A which is one of the pancreatic enzymes is also present as isoenzymes. Four forms of procarboxypeptidase-A haye been found in the bovine enzyme and three forms of the porcine enzyme. In human pancreatic juice four forms of procarboxypeptidase-A isoenzyme were found by isoelectric focusing method. Recently, the so-called isoamylase analysis was developed for the diagnostic use of amylase in pancreatic diseases. In alcohotic patients, the serum concentration of pancreatic isoamylase is subnormal and this lowered activity provides strong evidence for pancreatic exocrine insufficiency. The purpose of this study was to elucidate the variations of the isoenzyme of amylase and procarboxypeptidase-A in serum, saliva and pancreatic juice of the experimental animals. The results are as follow. 1) Three main forms of isoenzyme of amylase by isoelectric focusing were found in pancreatic juice of normal rabbit. However, many new bands were appeared in the pancreatic juice of cholic acid administered animal intravenously while the infusion of cholic acid or elastase into pancreatic duct produced the decrease of number of the fractions on the isoelectric focusing. In the case of serum isoenzyme from normal animal, two major and a few minor isoamylases were observed. By injecting alcohol intravenousely the fractions of serum isoamylase were significantly decreased and in contrary to the pattern in the pancreatic juice the infusion of cholic acid or elastase into pancreatic duct exhitited a significant decrease of the isoenzyme of amylase fractions. In saliva from normal animal three main isoamylase were produced of the administration of alcohol. 2) In the case of procarboxypeptidase-A isoenzyme, two major fractions which have isoelectric point at 6.2 and 6.4 and other two minor bands were observed in the pancreatic juice of normal rabbit. By the treatment of the juice with trypsin, only one band was produced on the isoelectric focusing. No procarboxypeptidase was appeared on the electrofocusing by the infusion of cholic acid or phospholipase A into the pancreatic duct of rabbit. However, a single major fraction of procarboxypeptidase-A was appeared at 3 hr after simple ligation of the pancreatic duct. No significant changes were observed in the juice of the alcohol or cholic acid administered group.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.187-194
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• 1998

Glycosides were synthesized using transglycosylation reaction of amylase in water system. Starch as a glycosyl donor and benzylalcohol as an acceptor were selected as substrates of transglycosylation reaction. Among tested 9 commercial amylase, amyloglucosidase from Rhizopus sp. had high activity for transglycosylation from starch. The glycoside synthesized in water phase by amyloglucosidase was identified as benzylalcohol-${alpha}$-glucoside (BG) of which one molecule of benzylalcohol was bound to 1-OH of glucose. The transglycosylation reaction by amyloglucosidase were carried out in reaction system containing 50 mg starch, 50 mg benzylalcohol, and 10 units enzyme in pH 5.0 at 45$^{\circ}C$. The synthesized BG was hydrolyzed by ${alpha}$-glucosidase to produce glucose and benzylalcohol.

• BMB Reports
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• v.35 no.6
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• pp.568-575
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• 2002

An $\alpha$-amylase (EC 3.2.1.1) was purified that catalyses the production of a high level of maltose from starch without the attendant production of glucose. The enzyme was produced extracellularly by thermophilic Streptomyces sp. that was isolated from Thailand's soil. Purification was achieved by alcohol precipiation, DEAE-Cellulose, and Gel filtration chromatographies. The purified enzyme exhibited maximum activity at pH 6-7 and $60^{\circ}C$. It had a relative molecular mass of 45 kDa, as determined by SDS-PAGE. The hydrolysis products from starch had $\alpha$-anomeric forms, as determined by $^1H$-NMR. This maltose-forming $\alpha$-amylase completely hydrolyzed the soluble starch to produce a high level of maltose, representing up to 90%. It hydrolyzed maltotetrose and maltotriose to primarily produce maltose (82% and 62%, repectively) without the attendant production of glucose. The high maltose level as a final end-product from starch and maltooligosaccharides, and the unique action pattern of this enzyme, indicate an unusual maltose-forming system. After the addition of the enzyme in the bread-baking process, the bread's volume increased and kept its softness longer than when the bread had no enzyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1079-1085
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• 2011

We investigated the biological activities of extracts from the flowers of Angelica gigas Nakai. The $IC_{50}$ of the DPPH radical scavenging activity was 3,535 and 105.0 ${\mu}g/mL$ in the water and ethanol extracts, respectively, whereas it was 12.7 ${\mu}g/mL$ for ascorbic acid. The results showed that the total polyphenol content of the ethanol extracts (48.43${\pm}$0.18 mg/g) was higher than that of the water extracts (39.03${\pm}$0.69 mg/g). The flavonoid content of the ethanol extracts (67.02${\pm}$4.38 mg/g) was higher than that of the water extracts (50.32${\pm}$1.24 mg/g). The ethanol extract showed a 34.45% lower ${\alpha}$-glucosidase inhibition activity than that for acarbose. The ethanol extract showed a 23.62% lower ${\alpha}$-amylase inhibition activity compared with that for acarbose. The water extract showed 16.76% lower pancreatic lipase inhibition activity. Anti-cancer and anti-inflammatory activity was also lower. These results suggest that the flower of Angelica gigas Nakai may be useful as an anti-oxidative agent.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.371-375
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• 1992

The ${\alpha}-amylase$ from Bacillus licheniformis was purified and its thermostability in the presence of substrate and metal was ions investigated. Comparing D-values of the enzyme obtained in the presence of $Ca^{++}$, $B^{+++}$ and both $Ca^{++}$ and $B^{+++}$, the thermostability of the enzyme was markedly enhanced by the addition of metal ions. $Ca^{++}$ and $B^{+++}$ exhibited a protective action, the former ion being more effective, and both ions showed a synergistic effect. The enthalpy of activation for the thermal inactivation in the presence of metal ion was 320.2 kJ/mole for $Ca^{2+}$ ion, 212.9 kJ/mole for $B^{+++}$, while it was 183.9 kJ/mole in the absence of metal ions. In the thermal inactivation for 30 min at $96^{\circ}C$, the residual activity in the presence of 30% (w/w) starch was 51.0%, whereas the presence of $Ca^{++}$ ion additionally provided a remarkable thermo-resistance.