• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.993-999
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• 2015

For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb and herb mixture extracts prepared through traditional antidiabetic prescription, this study examined ${\alpha}$-glucosidase inhibitory activity. Tyrosinase, a type I membrane glycoprotein, is synthesized and glycosylated in the endoplasmic reticulum (ER) and Golgi. The enzyme is subsequently transported to melanosomes, where it participates in melanogenesis. Previous studies showed that disruption of early ER N-glycan processing by an ${\alpha}$-glucosidase inhibitor suppresses tyrosinase enzymatic activity and melanogenesis. According to the results, most oriental medicinal herbal extracts were stronger than acarbose and N-butyldeoxynojirimycin, known as an ${\alpha}$-glucosidase inhibitor. Interestingly, ethyl acetate layer of enzyme hydrolyzed Cheongsimyeonjaeum had an inhibitory effect on melanin synthesis in B16F1 cells, although it did not inhibit tyrosinase activity directly. Together, ${\alpha}$-glucosidase inhibition activity could be used to evaluate anti-melanogenesis, although cross-checking with melanin inhibitory assay is recommended.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.439-442
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• 2004

Bacterial strains showing the firinolytic and $\beta$-glucosidase activity were screened from Doeniang. The strain of KH-15 revealed a high level of fibrinolytic and $\beta$-gluocosidase activity. The isolated bacterium was identified and desingnated as Bacillus sp. KH-15. The carbon, nitrogen and salts sgnificantly influenced te fibrinolytic enzyme and $\beta$-glucosidase production. The optimized composition of medium appeared to be 2％ glucose, 0.5% yeast extract and 0.1% calcium chloride. The optimum pH and temperature for fibrinolytic enzyme and $\beta$-glucosidase activities were pH 7∼8, 4$0^{\circ}C$ and pH 6∼8, 30∼4$0^{\circ}C$, respectively.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.244-250
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• 2000

An ${\alpha}-glucosidase$ gene (aglA) from thermophilic Bacillus sp. DG0303 was cloned, sequenced, and expressed in Escherichia coli. The aglA was localized to the 2.1-kb PvuI-XmnI region within the 5.9-kb DNA insert of the gybrid plasmid pAG1. The gene consisted of an open reading frame of 1,686 bp with an unusual GTG initiation codon and TGA termination codon. The amino acid sequence deduced from the nucleotide sequence predicted a protein of 562 amino acid residues with a M, of 66,551 dalton. A comparative amino acid sequence analysis revealed that DG0303 ${\alpha}-glucosidase$ is related to bacillary oligo-1, 6-glucosidases. The Bacillus sp. DG0303 ${\alpha}-glucosidase$ showed a high sequence identity (36-59%) to the B. flavocaldarius, B. cereus, and B. thermoglucosidasius oligo-1, 6-glucosidases. The number of prolines in theses four ${\alpha}-glucosidases. was observed to increase with increasing thermostability of these enzymes. The cloned ${\alpha}-glucosidase was purified from E. coli $DH5{\alpha}$ bearing pAG1 and characterized. The recombinant enzyme was identical with the native enzyme in its optimum pH and in its molecular mass, estimated by sodium dodecy1 sulfate-polyacrylamide gel electrophoresis. The temperature optimum of the cloned ${\alpha}-glucosidase$ was lower than that of the native enzyme.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.57-61
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• 1996

The $\beta$-glucosidase enzyme was purified from E. coli carrying Cellulomonas fimi $\beta$-glucosidase gene. SDS-PAGE and analytical gel filtration revealed that molecular weight of this enzyme was 56,000 dalton and consisted of a single polypeptide.Inhibition caused by heavy metals and activation by dithiothreitol suggest the existence of essential thiol group in the enzyme. The enzyme was not active on maltose (glucose $\alpha$-1,4-glucose) which has a $\alpha$-linkage, whereas it was active on lactose (glucose $\beta$-1,4-glucose), PNPG (p-nitrophenyl $\beta$-D-glucopyranoside) and PNPC (p-nitrophenyl $\beta$-D-cellobioside), although its reaction rates were different.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.381-383
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• 2014

In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.75-79
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• 2022

Antioxidant, α-glucosidase inhibition, and anticoagulant effects of 80% ethanolic extract from mistletoe (Viscum album var. coloratum) were investigated. The yield and polyphenol content of the mistletoe extract were 30.9±0.4% and 57.6±1.5 mg gallic acid equivalents/g, respectively. The antioxidant effects of the mistletoe extract such as free and cationic radical scavenging ability, nitrite scavenging ability, and reducing power increased in proportion to its concentration. Also the mistletoe extract inhibited the activity of α-glucosidase, and delayed plasma coagulation mainly by inhibiting the extrinsic and common pathways in blood coagulation system.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.174-179
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• 2015

For development a new anti-diabetic compound from edible mushroom, antihyperglycemic ${\alpha}$-glucosidase inhibitory activities of Pleurotus ostreatus, Pleurotus cornucopiae, Pleurotus salmoneostramineus, Pleurotus eryngii and Neolentinus lepideus were investigated on its water and ethanol extracts. ${\alpha}$-Glucosidase inhibitory activity of Neolentinus lepideus fruiting body showed the highest at 86.3% in the 95% ethanol extracts and water extract from Pleurotus cornucopiae was also higher at 48.5% among water extracts. Therefore, Neolentinus lepideus which showed very high ${\alpha}$-glucosidase inhibitory activity was selected as a new anti-diabetic agent-containing mushroom and the ${\alpha}$-glucosidase inhibitor was maximally extracted when treated with 95% ethanol at $30^{\circ}C$ for 48 hr. The ethanol extracts from Neolentinus lepideus fruiting body showed dosage-dependent hypoglycemic action after administration to 120 min in the SD-rat and streptozotocin-induced diabetic SD-rat.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.368-372
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• 2006

Quercetin is a flavonoid molecule that is known to tie in various sources of natural products such as vegetables and fruits. It has been proven that quercetin plays a crucial role in the prevention of colon cancer as well as homeostasis as radical scavenger in human body. It is also well-known that glycosidases, including $\alpha$-glucosidase, are involved in a variety of degenerative metabolic disorders. In the course of screening useful $\alpha$-glucosidase inhibitors, we screened out quercetin as a $\alpha$-glucosidase inhibitor from chemical libraries. Quercetin was shown to be a reversible, slow-binding, and noncompetitive inhibitor of yeast a-glucosidase with a K$_i$ value of $6.3\times10^{-8}$ M when it was included with an enzyme mixture. Together, these results show that quercetin has potential in treating disorders including diabetes, although the further mechanistic study is needed.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.335-340
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• 1986

Two kind of ${\beta}-glucosidase$, tightly-bound enzyme(TBE) and loosely-bound enzyme(LBE), were obtained from the conidia of Aspergillus nidulans. The existence of enzymes in conidia was conformed by the fact that these enzyme activities were proportional to the number of conidia. The levels of enzyme activities were independent of aging of the conidia. Enzymes were characterized partially. In spite of the physical and chemical treatments of conidia, there was no significant change in TBE activity. The optimum pH and temperature was 6.0 and $55^{\circ}C$, respectively. Thermostability of the TBE was remarkably higher than that of mycelial ${\beta}-glucosidase$. The electrophoretic pattern of LBE was identical to that of mycelial ${\beta}-glucosidase$. These results suggest that conidial ${\beta}-glucosidase$ are involved in adaptation process of the conidia to variable environments.

• KSBB Journal
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• v.5 no.2
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• pp.141-149
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• 1990

$\beta$-glucosidase derived from Aspergillus niger was immobilized by (1) covalent linkage on chitin and chitosan with glutaraldehyde, (2) adsorption on DEAE-cellulose and Amberite IRA93 after succinylation, and (3) entrapment on alginate and polyacrylamide gels with various cross linking agents. The retention yield of $\beta$-glucosidase immobilized on chitosan was 31.5% and operational stability was 69% after continuous operation at column reactor(5$0^{\circ}C$ at pH 4.8) for 15 days. The retention yield and operational stability were 24.7% and 60% respectively, in adsorption on Amberite IRA 93. On the other hand, the entrapment method by alginate and polyacrylamide gel was identified to be not appropriate due to the continuous elution of inlmobilized $\beta$-glucosidase. Optimum conditions for the immobilization on chitosan were also studied with optimum pH of 4.8 and glutaraldehyde concentration of 0.4%(w/v). The properties and stability of immobilized $\beta$-glucosidase are also investigted. The conversion yield of cellobiose to glucose was also analyzed using the column type enzyme reactor to evaluate the effectiveness of immobilized enzyme.