• Food Science and Biotechnology
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• v.15 no.6
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• pp.851-855
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• 2006

Acarviosine-glucose (AcvGlc) is an ${\alpha}$-glucosidase inhibitor and has similar inhibitory activity to acarbose in vitro. We synthesized AcvGlc by treating acarbose with Bacillus stearothermophilus maltogenic amylase and fed C57BL/6J and db/db mice with diets containing purified AcvGlc and acarbose for 1 week. AcvGlc (50 and 100 mg/100 g diet) significantly reduced plasma glucose and triglyceride levels in db/db mice by 42 and 51 %, respectively (p<0.0001). The hypoglycemic and hypotriglyceridemic effects of AcvGlc were slightly, but significantly, greater than those seen with acarbose treatment (p<0.0001) in C57BL/6J mice. In an oral glucose tolerance test, glucose tolerance was significantly improved at all time points (p<0.01). The expression of two novel glucose transporters (GLUTs), GLUT10 and GLUT12, were examined by Western blot analysis. GLUT10 was markedly increased in the db/db livers. After AcvGlc treatment, the expression of hepatic GLUT10 was decreased whereas intestinal GLUT12 was significantly increased in both strains of mice. Our results show that AcvGlc improves plasma lipid and glucose metabolism slightly more than acarbose. Regulation of hepatic GLUT10 and intestinal GLUT12 may be important in controlling blood glucose levels.

• Nutrition Research and Practice
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• v.13 no.1
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• pp.11-16
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• 2019

BACKGROUND/OBJECTIVES: Fasting and postprandial hyperglycemia should be controlled to avoid complications of diabetes mellitus. This study investigated the effects of autumn olive (Elaeagnus umbellata Thunb.) berry (AOB) on fasting and postprandial hyperglycemia in mice. MATERIALS/METHODS: In vitro ${\alpha}$-glucosidase inhibitory effect of AOB was determined. Maltose solution (2 g/kg) with and without AOB extract at 500 mg/kg or acarbose at 50 mg/kg was orally administered to normal mice after overnight fasting and glucose levels were measured. To study the effects of chronic consumption of AOB, db/db mice received the basal diet or a diet containing AOB extract at 0.4% or 0.8%, or acarbose at 0.04% for 7 weeks. Blood glycated hemoglobin and serum glucose and insulin levels were measured. Expression of adiponectin protein in epididymal white adipose tissue was determined by Western blotting. RESULTS: In vitro inhibitory effect of AOB extract on ${\alpha}$-glucosidase was 92% as strong as that of acarbose. The AOB extract (500 mg/kg) or acarbose (50 mg/kg) significantly suppressed the postprandial rise of blood glucose after maltose challenge and the area under the glycemic response curve in normal mice. The AOB extract at 0.4% or 0.8% of diet or acarbose at 0.04% of diet significantly lowered levels of serum glucose and blood glycated hemoglobin and homeostasis model assessment for insulin resistance values in db/db mice. The expression of adiponectin protein in adipose tissue was significantly elevated by the consumption of AOB at 0.8% of diet. CONCLUSIONS: Autumn olive (E. umbellata Thunb.) berry may reduce postprandial hyperglycemia by inhibiting ${\alpha}$-glucosidase in normal mice. Chronic consumption of AOB may alleviate fasting hyperglycemia in db/db mice partly by inhibiting ${\alpha}$-glucosidase and upregulating adiponectin expression.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.05a
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• pp.23-37
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• 2003

A novel inhibitor against maltose-producing a-amylase was prepared via stepwise degradation of a high molecular weight acarbose (HMWA) using Thermus maltogenic amylase (ThMA). The structure of the purified inhibitor was determined to be ${\alpha}$-D-glucopyranosyl-${\alpha}$-acarviosinyl-D-glucopyranose (GlcAcvGlc). Progress curves of p-nitrophenyl-${\alpha}$-D-maltoside (PNPG2) hydrolysis by various amylolytic enzymes, including maltogenase (MGase), ThMA, and cyclodextrinase(CDase) I-5, in the presence of acarbose or GlcAcvGlc indicated a slow-binding mode of inhibition. The inhibition potency of GlcAcvGlc for MGase, ThMA, and CDase I-5 was 3 orders of magnitude higher than that of acarbose.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.363-369
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• 2016

A putative cyclomaltodextrinase gene (licd) was found from the genome of Listeria innocua ATCC 33090. The licd gene is located in the gene cluster involved in maltose/maltodextrin utilization, which consists of various genes encoding maltose phosphorylase and sugar ABC transporters. The structural gene encodes 591 amino acids with a predicted molecular mass of 68.6 kDa, which shares less than 58% of amino acid sequence identity with other known CDase family enzymes. The licd gene was cloned, and the dimeric enzyme with C-terminal six-histidines was successfully produced and purified from recombinant Escherichia coli. The enzyme showed the highest activity at pH 7.0 and 37℃. licd could hydrolyze β-cyclodextrin, starch, and maltotriose to mainly maltose, and it cleaved pullulan to panose. It could also catalyze the hydrolysis of acarbose to glucose and acarviosine-glucose. In particular, it showed significantly higher activity towards β-cyclodextrin and maltotriose than towards starch and acarbose. licd also showed transglycosylation activity, producing α-(1,6)- and/or α-(1,3)-linked transfer products from the acarbose donor and α-methyl glucopyranoside acceptor.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1418-1425
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• 2000

Obesity and diabetes mellitus are associated with common pathogenic mechanism, and ${\beta}-glucan$ of Agaricus blazei Murill is potent inhibitor of intestinal ${\alpha}-glycosidase$ and inhibit the digestion of starch and sucrose in the small intestine. In this studies, there was observed the anti-hyperglycemic effect in obese diabetic mice(C57BLKsJ db/db), which were supplied Agaricus and Acarbose for 5 weeks. In db/db mice, food intake and body weight gain were decreased significantly in Agaricus groups(p<0.05). Also these group exhibited lower fasting serum glucose level compared with control group. HbA1c level, triglyceride level, total cholesterol level, HDL cholesterol level, LDL cholesterol level and VLDL cholesterol level were lowered in db/db mice. The activity of disaccharidases on proximal and distal segments of small intestine was decreased. In conclusion, it was assumed that ${\beta}-glucan$ of Agaricus blazei Murill has anti-hyperglycemic and anti-obesitic effects by reducing food intake and body weight gain, and also decreasing serum glucose and lipid level through inhibiting the activity of small intestinal disaccharidases.

• Nutrition Research and Practice
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• v.9 no.3
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• pp.262-267
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• 2015

BACKGROUND/OBJECTIVES: The primary objective of the treatment of diabetes mellitus is the attainment of glycemic control. Hyperglycemia increases oxidative stress which contributes to the progression of diabetic complications. Thus, the purpose of this study was to investigate the hypoglycemic and antioxidant effects of Daraesoon (Actinidia arguta shoot) in animal models of diabetes mellitus. MATERIALS/METHODS: Rats with streptozotocin-induced diabetes received an oral administration of a starch solution (1 g/kg) either with or without a 70% ethanol extract of Daraesoon (400 mg/kg) or acarbose (40 mg/kg) after an overnight fast and their postprandial blood glucose levels were measured. Five-week-old C57BL/6J mice were fed either a basal or high-fat/high-sucrose (HFHS) diet with or without Daraesoon extract (0.4%) or acarbose (0.04%) for 12 weeks after 1 week of adaptation to determine the effects of the chronic consumption of Daraesoon on fasting hyperglycemia and antioxidant status. RESULTS: Compared to the control group, rats that received Daraesoon extract (400 mg/kg) or acarbose (40 mg/kg) exhibited a significant reduction in the area under the postprandial glucose response curve after the oral ingestion of starch. Additionally, the long-term consumption of Daraesoon extract or acarbose significantly decreased serum glucose and insulin levels as well as small intestinal maltase activity in HFHS-fed mice. Furthermore, the consumption of Daraesoon extract significantly reduced thiobarbituric acid reactive substances and increased glutathione levels in the livers of HFHS-fed mice compared to HFHS-fed mice that did not ingest Daraesoon. CONCLUSIONS: Daraesoon effectively suppressed postprandial hyperglycemia via the inhibition of ${\alpha}$-glucosidase in STZ-induced diabetic rats. Chronic consumption of Daraesoon alleviated fasting hyperglycemia and oxidative stress in mice fed a HFHS diet.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.5-8
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• 2015

This study was to isolate an active component of the chloroform fraction from the methanol extract of Ruta chalepensis leaves and to measure inhibitory effects against ${\alpha}$-glucosidase or ${\alpha}$-amylase. The inhibitory compound of R. chalepensis leaves was isolated using chromatographic methods and identified as quinoline. Quinoline and its structurally related derivatives were tested for their inhibitory activities by evaluating the $IC_{50}$ values against ${\alpha}$-amylase or ${\alpha}$-glucosidase and were compared with that of acarbose. Based on the $IC_{50}$ values, quinazoline exhibited the greatest inhibitory activity ($20.5{\mu}g/mL$), followed by acarbose ($66.5{\mu}g/mL$), and quinoline ($80.3{\mu}g/mL$) against ${\alpha}$-glucosidase. In case of ${\alpha}$-amylase, quinazoline had potent inhibitory activity, followed by quinoline ($179.5{\mu}g/mL$) and acarbose ($180.6{\mu}g/mL$). These results indicate that R. chalepensis extract, quinoline, and quinazoline could be useful for inhibiting ${\alpha}$-glucosidase or ${\alpha}$-amylase.

• Journal of Nutrition and Health
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• v.31 no.2
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• pp.117-125
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• 1998

Mulberry leaves(Mori folium) and silkworm(Bombyx mori) are potnet inhibiters of intestinal $\alpha$-glycosidase, and inhibit the digestion of starch and sucrose in the small intestine. They are able to prevent postprandial hyperglycemia and decrease blood insulin levels. In this study , a high-carbohydrate diet(CHO ; 67.5%, protein ; 20.8%, fat : 11.7%) was received by the control group. In contrast, the experimental groups received a high-carbohydrate diet with extracts of mulberry leaves and silkwork(50mg.100g diet), and acarbose(6.7mg/100g diet). after a 10 week study period , the experimental groups had lower blood glucose and triglyceride levels. The experimental groups tended to have lwer Hb Alc levels. Also, blood insulin levels were lower than the control groups in accordance with blood glucose levels. The activities of intestinal $\alpha$-glucosidase in the middle and distal parts of small intestine were induced by the extracts of mulberry leaves and silkworm in the experimental groups. However, the activities of liver lysosomal glucosidase and the contents of glycogen in the liver were not affected by the mulberry leave and silkworm extracts nor by acarbose. Mulberry leaves and silkworm were able to prevent sudden postprandial peaks in blood glucose as a result of $\alpha$-glycosidase, inhibition, there by decreasing unnecessary insulin secretion.

• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1401-1407
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• 2008

The roles of conserved amino acid residues (Va1329-Ala330-Asn331-Glu332), constituting an extra sugar-binding space (ESBS) of Thermus maltogenic amylase (ThMA), were investigated by combinatorial saturation mutagenesis. Various ThMA mutants were firstly screened on the basis of starch hydrolyzing activity and their enzymatic properties were characterized in detail. Most of the ThMA variants showed remarkable decreases in their hydrolyzing activity, but their specificity against various substrates could be altered by mutagenesis. Unexpectedly, mutant H-16 (Gly-Leu-Val-Tyr) showed almost identical hydrolyzing and transglycosylation activities to wild type, whereas K-33 (Ser-Gly-Asp-Glu) showed an extremely low transglycosylation activity. Interestingly, K-33 produced glucose, maltose, and acarviosine from acarbose, whereas ThMA hydrolyzed acarbose to only glucose and acarviosine-glucose. These results propose that the substrate specificity, hydrolysis pattern, and transglycosylation activity of ThMA can be modulated by combinatorial mutations near the ESBS.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.227-232
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• 2013

We studied antioxidant activity and inhibitory effect of ${\alpha}$-glucosidase from aqueous, ethanolic and methanolic fractions of Galla rhois. In FRAP and ORAC assay for measuring antioxidant activity, we confirmed that Galla rhois extracts had strong antioxidant activity and ethanolic and methanolic extracts were relatively stronger than aqueous extract. We used trolox as a positive control. In order to measure the inhibitory effect of ${\alpha}$-glucosidase, we compared acarbose and Galla rhois extracts. As a result of ${\alpha}$-glucosidase inhibitory assay, aqueous, ethanolic and methanolic extracts of Galla rhois showed high inhibitory activitity and ethanolic and methanolic extracts were relatively stronger than aqueous extract. The 50% inhibitory concentrations (IC50s) of acarbose, aqueous, ethanolic and methanolic fractions were 0.45 mM, $0.53{\mu}g/ml$, $0.415{\mu}g/ml$ and $0.37{\mu}g/ml$, respectively. These results suggest that Galla rhois extracts can be a clinically useful anti-diabetic ingredient, indicating that it needs to be fractionated and isolated and should be further investigated.