• Analytical Science and Technology
• /
• v.9 no.3
• /
• pp.235-243
• /
• 1996

A carbon paste electrode were chemically modified using ${\alpha}$-cyclodextrin. Characteristics of chemically modified carbon paste electrodes were studied on the basis of the inclusion complex formation of ${\alpha}$-cyclodextrin and p-nitrophenol in solution. Cyclic voltammetry and differential pulse voltammetry were used to monitor the efficiency of the chemical modification. When the ${\alpha}$-cyclodextrin and carbon powder ratio of 2 : 1 in weight were used, the reduction peak current of p-nitrophenol was decreased almost completely, whereas those of o-nitrophenol and hydroquinone were not changed much. This result is due to the large difference in the inclusion complex formation constants of p-nitrophenol and the other probes with ${\alpha}$-cyclodextrin. Taking advantage of this difference, we can determine the concentration of o-nitrophenol even in the presence of p-nitrophenol.

• YAKHAK HOEJI
• /
• v.6 no.1
• /
• pp.35-41
• /
• 1962

전분액은 Bac. macerans로 분해시킬때 Cyclodextrin이 형성되는 것은 Schardinger Freudenberg등에 발견된 사실이었으나 아직도 그 정확한 생성량에 대한 정량적인 조사는 되어있지 않으므로 저자는 본 연구를 통하여 .alpha.-, .betha.-, .gamma.-dextrin의 정량법을 paper-chromatography법으로 확립시켰다. 또한 이때 각분자와 주분자의 포위화합물의 현미경사진에 의한 결정형성모양과 동시에 그 모액중에 있는 Cyclodextrin의 함량등으로 cyclodextrin의 포위성을 증명하는 실험과 이러한 사실에 기인하여, Enzyme액으로 cyclodextrin이 생성되어 나올때 그 생성률의 변화를 조사한 결과를 cyclohexan을 첨가해 줄때 그 생성률이 가장 양호해지는 것을 보았다. 또한 본 연구를 통하여 .alpha.-Dextrin을 Enzyme과 공동작용시키면 .betha.-Dextrin이 형성되어 지는데, 각분자의 첨가로 그 .betha.-Dextrin의 생성량이 증가해지며 이때 Glucose를 가해주면 그 반응이 촉진되어 여기에 하나의 척매적인 작용을 하는 것으로 본다. 이것은 전분이 효소로써 분해될때 직쇄의 Dextrin이 생긴 다음 이것이 glucosyl기 전이반응의 반복으로써 Cyclodextrin이 형성되는 것을 입증하는 것인데 Glucosyl 기의 공여체로써 Glucose및 Maltose를 사용하였을때 이와같은 사실이 촉진되는 것을 볼 수 있다. 그러나 이와 같은 촉매적 역할에도 불구하고 .betha.-Dextrin을 Enzym과 공동작용시켜도 .alpha.-Dextrin이 형성되지 않는 것을 보아 .alpha.-Dextrin과 .betha.-Dextrin의 상호변화에 대해서 우리는 .alpha.-Dextrin에서 .betha.-Dextrin으로는 변화할수 있으나 .betha.-Dextrin으로 부터 .alpha.-Dextrin으로는 변화가 진행되지 않는 것으로 본다. 전반적으로 본 연구를 통하여 전분액을 Bac. macerans로 분해시킬때 시간의 경과를 따라 생성되어지는 Cyclodextrin의 함량의 변화를 추적하여 4시간전후에서 최고량이 되는 것을 볼 수 있으며 동시에 포위화합물을 형성시킬수 있을때는 그 생성률이 큰 영향을 이르킬수 있는 것을 지적할 수 있다.

• Analytical Science and Technology
• /
• v.13 no.5
• /
• pp.549-557
• /
• 2000

FRIR-ATR spectrometry has been used to monitor the aqueous reactions of compounds without distinct chromophores in ultraviolet and visible regions. For example, hydrolysis reactions of ${\alpha}$-cyclodextrin and ${\gamma}$-cyclodextrin in acidic aqueous solution were studied. FTIR-ATR method has been used for the monitoring of cyclodextrin hydrolysis in 1.0 M. 0.5 M, and 0.1 M HCl solutions, respectively. We also found that the hydrolysis of ${\alpha}$-cyclodextrin produced glucose, but the hydrolysis of ${\gamma}$-cyclodextrin proceeded further to give more fragmented products than glucose.

• Bulletin of the Korean Chemical Society
• /
• v.13 no.5
• /
• pp.474-479
• /
• 1992

Molecular interaction between ${\alpha}$-cyclodextrin and aspirin was studied by UV, $^2H$-NMR and $^2H$-NMR spectroscopy analyses for solution complex and by FT-IR analyses for solid complex. The inclusion structure provides a basic understanding of the aspirin and ${\alpha}$-cyclodextrin interaction.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.10
• /
• pp.3083-3087
• /
• 2013

Diacetylene lipid monomers possess the capability to self-assemble into vesicles via polymerization under ultraviolet irradiation, resulting in the formation of polydiacetylene (PDA) liposomes. Exposure of the polymerized vesicles to external stimuli is known to induce a unique blue-to-red color transition. The cyclic oligosaccharide ${\alpha}$-cyclodextrin known for its use in many applications, such as drug delivery, purification, and stimulus sensing, is able to form an inclusion complex with poly(ethylene glycol) (PEG) in aqueous solution. In this study, we prepared polymeric liposomes with PEG (PEG-PDA) with the aim of improving the stability of the vesicles and colorimetric response toward ${\alpha}$-cyclodextrin. We demonstrated that PEG-PDA liposome displays unique characteristics compared with native PDA liposome and it also shows apparent chromic properties of the inclusion complex formation with ${\alpha}$-cyclodextrin.

• Korean Journal of Food Science and Technology
• /
• v.22 no.7
• /
• pp.802-804
• /
• 1990

A new colorimetric method to analyze ${\alpha}-Cyclodextrin({\alpha}-CD)$ by using a property of ${\alpha}-CD$ to decolor the starch-iodine complex, was presented. ${\alpha}-CD$ was quantitatively determined as follows. The ${\alpha}-CD$ standard solutions at concentrations up to 2 mg/ml were prepared. To 1ml of starch-iodine complex solution which contained starch(1%) and iodine (0.02% $I_2$, 0.2% KI) equivalently in distilled water, $200\;{\mu}l$ of ${\alpha}-CD$ standard solutions and 3 ml of distilled water were added and the absorbance was measured at 570 nm. Using this mothod ${\alpha}-CD$ concentration range at $0{\sim}2\;mg/ml$ could be determined and their absorbance patterns at 570 nm showed a good linearity. ${\beta}(CD)$ and glucose had no interference in this method for ${\alpha}-CD$ determination.

• The Korean Journal of Food And Nutrition
• /
• v.11 no.2
• /
• pp.159-164
• /
• 1998

pH stability of sweet potato $\beta$-amylase modified with IO4-oxidized soluble starch was increased at pH 3, 5~9 and 11. And optimum pH was 3 and 5 for modification. Thermal stability of the enzyme modified with IO4-oxidized soluble starch was increased at 6$0^{\circ}C$ for 15 min. pH stability of barley $\beta$-amylase modified with IO4-oxidized soluble starch was increased at 3~4 and 8~11, and more increased at pH 3 and 8~11 in the presence of $\alpha$-cyclodextrin.

• KSBB Journal
• /
• v.9 no.5
• /
• pp.499-505
• /
• 1994

Bacillus macerans cyclodextrin glucanotransferase(EC 2.4.1.19: 1, 4-${\alpha}$-D(1, 4-${\alpha}$-glucano)-transferase, CGTase) was purified by the technique of starch adsorption and DEAE-cellulose column chromatography. The molecular weight of the enzyme was 67,000, consisting of a subunit. The enzyme converted starch into ${\alpha}$-, ${\beta}$-, and ${\gamma}$-CD in the relative amounts of 1:1.68:0.32, respectively. In the early reaction period, maltohexose was formed mainly by the coupling reaction of ${\alpha}$-CD with D-glucose and then other oligosaccharides. Maltotetrose was formed mainly from ${\alpha}$-CD in the initial stage of hydrolysis of the enzyme and then small amount of other oligosaccharides. Maltotriose was a good substrate for the enzyme and maltosyl or D-glucopyranosyl group can be transfered from this sugar. In this work, D-glutosyl transfer was premiered.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.3
• /
• pp.61-66
• /
• 1998

Cyclodextrin are obtained from starch by enzymatic degradation. The three best characterize forms are ${\alpha}$, ${\beta}$, ${\gamma}$ cyclodextrin consisting of 6, 7, and 8 D-glucose units, respectively. Each of the glucose units are in the rigid C1 chair conformation and are linked by ${\alpha}$ 1,4 bonds. This geometry gives the cyclodextrin the shape of a hollow truncated cone with the wider side formed by the secondary 2- and 3-hydroxy groups and the narrower side by the primary 6-hydroxy group. The most characteristics property of the cyclodextrin is their ability to form inclusion complexes with a wide range of guest moleculars. We syntheses per-6-substituted ${\beta}$-cyclodextrin derivatives and investigate structures, spectrospcopic properties. The substituted materials are piperidine, piperazin, morphorine. The synthetic compound showed a good solubility than natural ${\beta}$ cyclodextrin in organic solvents such as methylene chloride, methanol, ethanol, etc.

• Microbiology and Biotechnology Letters
• /
• v.19 no.5
• /
• pp.514-520
• /
• 1991

Direct synthesis of cyclodextrin (CD) from extruded insoluble corn starch without liquefaction procedure using cyclodextrin glucanotransferase (CGTase) was carried out. Increased CD production rate and yield were achieved in heterogeneous enzyme reaction system containing extruded corn starch compared with those of conventional system employing liquefied or partially cyclized starch. At extruded starch concentration of 100 g/l the CD concentration and conversion yield were reached up to 54 g/l and 0.54, respectively. High purity of $\alpha \beta \gamma$-CDs without accumulation of undesirable malto-oligosaccharides was produced, furthermore, the residual extruded starch was easily separated by centrifugation from reaction mixture, whlch will facilitate the purification procedure. Granular structure of extruded starch was observed by SEM to investigate enzyme reaction mechanism. Supplemental addition of $\alpha$-amylase enhanced slightly the initial CD production rate, but it decomposed produced CD at the late stage. Various! extruded raw starches, such as, corn, rice, and barley were also suitable substrates for CD production.