• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.82-85
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• 1998

1. 서론 : Cyclodextrin(CD) 동족체(homologues)는 $\alpha$-, $\beta$-, $\gamma$-CD로 구분되며, 이들 각각은 $\alpha$-D-glucopyranose 단위체 6,7, 및 8개가 비환원성 환상구조로 연결된 cyclic maltooligosaccaride의 일종으로 외부는 친수성이고, 내부는 소수성인 공동 구조를 갖고 있다. 따라서 각 CD는 동공의 크기가 달라 다른 크기의 소수성 물질들과 선택적인 포접화합물 (inclusion compound)을 형성하는 특징이 있다. CD 동족체는 전분 분해 효소인 cyclodextrin glycosyltransferase(CGTase)에 의해 전분으로부터 생산되는데, 반응용액 내에서의 CD 동족체 농도가 어느 한계값 이상으로 높아지면 생산물 저해와 다른 환원당으로의 분해 때문에 생산성이 감소하여 이의 효과적 생산에 어려움이 있다. 본 연구는 dead-end 및 cross-flow형 막 생물반응기를 사용하여 CGTase에 의한 전분의 CD 동족체로의 분해반응시 생산물 저해를 억제시켜 생산성을 향상시키고, 동시에 조작조건 변화에 따른 생산물인 CD 동족체의 효과적인 연속분리 가능성을 검토하였다.

• Membrane Journal
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• v.8 no.3
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• pp.170-176
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• 1998

A study on the bioconversion of soluble starch to cyclodextrin(CD) homologue by CGTase was performed in the membrane-enzyme reactor equipped with a dead-end type membrane module. in the batch reactor, the total conversion of soluble starch to CD homologue was decreased rapidly from a maximum value of 45 % with increasing reaction time due to the product inhibition and breakdown of CD homologue to the reducing sugars. However, in the membrane-enzyme reactor, the total conversion of soluble starch was maintained at a constant value of 35 % throughout the reaction, since the membrane(MWCO = 10,000) promptly separated CD homologue from the reaction mixture. After the macdon for 24 hr in the membrane-enzyme reactor using a 10 % soluble starch solution, the cumulative production amount of CD homologue was about 3.7 kg/m$^2$ at the operating pressure of 2 atm.

• Journal of the Korean Chemical Society
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• v.35 no.3
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• pp.262-267
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• 1991

Bromo-acivicin derivative(17) and its homologs(15,16,8) were synthesized by 1,3-dipolar cycloaddition of vinyl glycine derivative(13) and allylglycine derivatives(9,12), respectively, with bromonitrile oxide(5).

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.511-521
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• 2006

Homologue and isomer patterns of polychlorinated dibenzo-p-dioxins(PCDDs) and polychlorinated dibenzofurans(PCDFs) congeners formed from phenols in the gas-phase at $600{\sim}700^{\circ}C$ and via particle-mediated reactions at $400^{\circ}C$ were studied in an isothermal flow reactor. A mixture of 20 phenols in relative concentrations found in a municipal waste incinerator(MWI) stack gas was used for this study. PCDDs and PCDFs homologue and isomer patterns obtained from the phenol. From the phenol experiments, gas-phase formation at $600{\sim}700^{\circ}C$ favors PCDFs formation whereas particle-mediated formation at $400^{\circ}C$ favors PCDDs formation. DD and DF were most abundant homologue groups, PCDDs and PCDFs homologue fraction decreased with increasing number of chlorine substituents. PCDDs and PCDFs homologue and isomer fractions were almost constant from gas-phase formation and particle-mediated formation. Unsubstituted phenol, which was present in high concentration, played a significant role in the formation of PCDD/Fs congeners under both sets of experimental conditions.

• 월간산업보건
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• s.18
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• pp.13-17
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• 1989

• 월간산업보건
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• s.3
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• pp.22-27
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• 1988

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.73-84
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• 1995

Four malformin A's produced by Aspergillus niger van Tiegh. were separated by HPLC equipped with $C_{18}$ reversed-phase column and subjected to structural determination. Amino acid analyses and mass spectra data of the compounds indicate that they structurally resemble the cyclic pentapeptide malformin $A_1$. Their structures were deduced by two dimensional NMR and MS/MS experiments as cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-Ile for $A_1$, cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-Val for $A_2$, cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-Leu for $A_3$, and cyclo-D-Cys-D-Cys-L-Val-D-Ile-L-Val for $A_4$. Among the mal-formin A's, the structure of $A_3$ was identical to that of malformin C, which was produced by A. niger strain AN-1. All the malformin A's caused severe curvatures of corn(Zea mays L.) roots and the activities of the malformin A's with molecular weight 529 were greater than those with molecular weight 515. Malformin $A_1$ caused the corn root curvature by 83% at a concentration of $0.25{\mu}M$. In the mung bean(Phaseolus aureus Roxb.) hypercotyl segment test, however, the molecular weight of malformin A's was not a factor influencing the physiological activities. Malformin $A_1$ stimulated the growth of mung bean hypercotyles by 165% at a $0.1{\mu}M$ concentration.

• The Safety technology
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• no.115
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• pp.82-85
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• 2007

• 월간산업보건
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• s.4
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• pp.30-38
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• 1988

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.640-652
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• 1994

This work is undertaken to determine alcohol homologues so-called fusel oil that may be present in the Korean folk sojues (distilled liquor) made from grains and to describe sample preparation and analytical method by GC-FID-MS. Solid phase extraction method for sample preparation by using porous styrene divinyl benzene polymer (Porapak Q) was compared with steam distillation and solvent extraction method. Retention behaviors of homologous series of alcohols were also studied. Log values of retention time, molecular weight, boiling point, and capacity factor of alcohols showed linear correlations to the carbon number of an alcohol, to the oven temperature, and to the dielectric constant. Components such as methyl alcohol, n-propyl alcohol, isobutyl alcohol, isopentyl alcohol, and phenethyl alcohol have been identified. The more amount of isopentyl alcohol than other alcohols are contained in the Korean folk sojues, while that of n-propyl alcohol are contained in Chinese kaoliangchiew. Degree of similarity or dissimilarity and classification of the individual samples were discussed using multivariate statistical analysis(principal components analysis) based on GC data.