• 미생물학회지
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• 제10권3호
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• pp.106-108
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• 1972

The enzyme was produced by Asp.oryzae SHW 131. the enzymatic properties of .alpha.-amylase are following : 1) Crystallization of .alpha.-amylase is formed of longish square. 2) The range of stable pH is 5-10 and optimum ph is 5.5. 3) It is very unstable enzyme about EDTA and protection by $Ca^{++}$ ion and best activated at $50^{\circ}C$ about temperature. 4) Asp.oryzae SHW 131 produced .alpha.-amylase with acid-protease, neutral-protease and tepid-alkalin-protease.

• 미생물학회지
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• 제10권3호
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• pp.105-105
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• 1972

The enzyme was produced by Asp.oryzae SHW 131. the enzymatic properties of .alpha.-amylase are following : 1) Crystallization of .alpha.-amylase is formed of longish square. 2) The range of stable pH is 5-10 and optimum ph is 5.5. 3) It is very unstable enzyme about EDTA and protection by $Ca^{++}$ ion and best activated at $50^{\circ}C$ about temperature. 4) Asp.oryzae SHW 131 produced .alpha.-amylase with acid-protease, neutral-protease and tepid-alkalin-protease.

• Food Science and Biotechnology
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• 제18권3호
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• pp.667-671
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• 2009

Extract of water-soluble polysaccharide (CFWx), showing inhibiting activity on ${\alpha}-glucosidase$, was prepared from the fruiting bodies of Cordyceps militaris by hot-water extraction, and ethanol precipitation. Chemical characteristics of CFWx were as follows: carbohydrate content 30% including 16% of uronic acid; 51% protein content; monosaccharide composition, Man:Glu:Gal (30:43:27); molecular weight $3-5{\times}10^4$. CFWx was further purified by ion-exchange, gel-permeation, and affinity chromatography and $CFWx-AH-{\alpha}$ fraction was isolated. Fundamental structure of $CFWx-AH-{\alpha}$ was deduced as ${\alpha}-(1{\to}4$)-D-glucan with ${\alpha}-(1{\to}3$)- and/or ${\alpha}-(1{\to}6$)-D-glycosidic side chains based on methylation analysis.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.370.1-370.1
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• 2002

Prunella vulgaris var. lilacina (Labiatae) has been used as a Korean traditional medicine for the treatment of. fever. inflammation. urinary disadvantage and cancer. We previously isolated three $\alpha$-amyrin triterpenoids from n-butanol-I extract. They are 3$\alpha$-hydroxyurs-12-ene-28-oic acid (ursolic acid). 2$\alpha$, 3$\alpha$-dihydroxyurs-12-ene-28-oic acid and 2$\alpha$. 3$\alpha$. 19$\alpha$ trihydroxyurs-12-ene-28-oic acid (euscaphic acid) exhibiting cytotoxicity and topoisomerase I inhibition. (omitted)

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1551-1554
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• 2010

Two diastereomeric chiral stationary phases (CSPs) were applied to the liquid chromatographic resolution of various racemic ${\alpha}$-amino methyl esters, ${\alpha}$-amino N,N-diethylamides and ${\alpha}$-amino N-propylamides. The CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (R,R)-tartaric acid unit as chiral barriers did not show any chiral recognition. In contrast, the CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (S,S)-tartaric acid unit as chiral barriers was found to show excellent chiral recognition especially for the two enantiomers of ${\alpha}$-amino N-propylamides. Some of ${\alpha}$-amino methyl esters and ${\alpha}$-amino N,N-diethylamides were also resolved on the CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (S,S)-tartaric acid unit. From these results it was concluded that the two chiral units composing the diastereomeric CSPs can show "matched" or "mismatched" effect on the chiral recognition according to their absolute stereochemistry.

• 한국세라믹학회지
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• 제28권2호
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• pp.130-140
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• 1991

The powders of the system Si3N4-Y2O3-AlN were prepared using Si(OC2H5)4 and YCl3.6H2O together with commercial AlN powder. $\alpha$-Si3N4 was prepared by the carbothermal reduction and nitridation of the hydrolyzed gel at 135$0^{\circ}C$ for 10h in N2 atmosphere. YCl3.6H2O was observed to be changed to Y2O3 during the reaction. $\alpha$-Sialon(X=0.2, 0.4, 0.6) ceramics were obtained by hot-pressing the Si3N4-Y2O3-AlN mixture at 178$0^{\circ}C$ for 1h under 30 MPa. The content of $\alpha$-Sialon increased with increasing metal solubility(x value) and $\alpha$-Sialon single phase was obtained at the metal solubility of 0.6. With increasing metal solubility, flexural strength, fracture toughness and thermal shock resistence were decreased, while the microhardness was increased. Large elongated $\beta$-Si3N4 grains were mainly observed at lower metal solubility. Mechanical prorerties of the sintered ceramics with X=0.2 were measured as follows : flexural strength ; 650 MPa, fracture toughness ; 3.63 MN/m3/2, hardness ; 14.7 GPa, thermal shock resistence temperature ; 58$0^{\circ}C$.

• 한국세라믹학회지
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• 제34권11호
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• pp.1159-1164
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• 1997

Magnetite(Fe3O4) powders were synthesized through glycothermal reaction by using crystalline $\alpha$-FeOOH as precursor and ethyleanne glycol as solvent. The phase, morphology and particle size of synthesized powders were characterized by XRD and an SEM. When only ethylene glycol was used as solvent, the phase was transformed from $\alpha$-FeOOH to $\alpha$-Fe2O3 and finally Fe3O4 at 27$0^{\circ}C$ for 6hr without morphological change. But by addition of water, Fe3O4 powders were synthesized at 23$0^{\circ}C$ for 3hr through solution-recrystalization process. As the content of water addition increased, the particle shape changed from sphere to octahedron and the partcle size increased. When the excess amount of water added, residual $\alpha$-FeOOH or $\alpha$-Fe2O3 was recrystalized.

• 약학회지
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• 제41권5호
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• pp.575-581
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• 1997

The 6,7-dichlorquinoline-5,8-dione was reacted with ${alpha}$-cyanoacetic acid ethyl ester in ammonia solution to yield 6-(${alpha}$-cyano-${alpha}$-ethoxycarbonyhnethyl)-7-chloroquinoline- 5,8-dione (compound I). When this compound was reacted with some alkyl amines (methylamine, ethylamine, isopropylamine, etc) 2-amino-3-ethoxycarbonyl-N-alkyl-pyridino[2,3-f]indole-4,9-diones (compounds II a-e) were obtained.

• Preventive Nutrition and Food Science
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• 제22권3호
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• pp.166-171
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• 2017

In this study, we investigated whether Sargassum yezoense extract (SYE) could inhibit ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities, and alleviate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Freeze-dried S. yezoense was extracted with 80% ethanol and concentrated for use in this study. The hypoglycemic effect was determined by evaluating the inhibitory activities of SYE against ${\alpha}-glucosidase$ and ${\alpha}-amylase$ as well as its ability to decrease postprandial blood glucose levels. The half-maximal inhibitory concentrations of SYE against ${\alpha}-glucosidase$ and ${\alpha}-amylase$ were $0.078{\pm}0.004$ and $0.212{\pm}0.064mg/mL$, respectively. SYE was a more effective inhibitor of ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities than the positive control, acarbose. The increase in postprandial blood glucose levels was significantly alleviated in the SYE group compared with that in the control group of STZ-induced diabetic mice. Furthermore, the area under the curves significantly decreased with SYE administration in STZ-induced diabetic mice. These results suggest that SYE is a potent inhibitor of ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities and alleviates postprandial hyperglycemia caused by dietary carbohydrates.

• 대한수학회논문집
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• 제25권3호
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• pp.349-364
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• 2010

P. M. Cohn called a ring R reversible if whenever ab = 0, then ba = 0 for a, $b\;{\in}\;R$. Commutative rings and reduced rings are reversible. In this paper, we extend the reversible condition of a ring as follows: Let R be a ring and $\alpha$ an endomorphism of R, we say that R is right (resp., left) $\alpha$-shifting if whenever $a{\alpha}(b)\;=\;0$ (resp., $\alpha{a)b\;=\;0$) for a, $b\;{\in}\;R$, $b{\alpha}{a)\;=\;0$ (resp., $\alpha(b)a\;=\;0$); and the ring R is called $\alpha$-shifting if it is both left and right $\alpha$-shifting. We investigate characterizations of $\alpha$-shifting rings and their related properties, including the trivial extension, Jordan extension and Dorroh extension. In particular, it is shown that for an automorphism $\alpha$ of a ring R, R is right (resp., left) $\alpha$-shifting if and only if Q(R) is right (resp., left) $\bar{\alpha}$-shifting, whenever there exists the classical right quotient ring Q(R) of R.