• Bulletin of the Korean Chemical Society
• /
• 제32권8호
• /
• pp.2565-2570
• /
• 2011

The reaction of bromoacetonitrile with 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[$16.4.1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^{10}$) containing a N-$CH_2$-N linkage produces 17-cyanomethyl-3,14-dimethyl-2,6,13,17-tetraazatetracyclo-[$16.4.1^{2.6}.0^{1.18}.0^{7.12}$]tricosane ($L^{11}$). The mono-N-functionalized macrocyclic complexes $[ML^2]^{2+}$ (M = Ni(II) or Cu(II); $L^2$ = 2-cyanomethyl-5,16-dimethyl-2,6,13,17-tetraazatricyclo[$16.4.0.0^{7.12}$]docosane) can be prepared by the reaction of $L^{11}$ with nickel(II) or copper(II) ion in acetonitrile. The N-$CH_2CN$ group attached to $[ML^2]^{2+}$ readily reacts with water or methanol to yield the corresponding complexes of $HL^3$ bearing one N-$CH_2CONH_2$ pendant arm or $L^4$ bearing one $N-CH_2C(=NH)OCH_3$ group. The $N-CH_2CONH_2$ or $N-CH_2C(=NH)OCH_3$ group of each complex is coordinated to the central metal ion. Both $[NiL^4(H_2O)]^{2+}$ and $[CuL^4]^{2+}$ are quite stable in acidic aqueous solutions, but undergo hydrolysis to yield $[Ni(HL^3)(H_2O)]^{2+}$ or $[Cu(HL^3)]^{2+}$ in basic aqueous solutions. In contrast to $[Cu(HL^3)]^{2+}$, $[Ni(HL^3) (H_2O)]^{2+}$ is readily deprotonated to form $[NiL^3 (H_2O)]^+$ ($L^3$ = a deprotonated form of $HL^3$) in basic aqueous solutions.

• Journal of Life Science
• /
• 제8권6호
• /
• pp.660-666
• /
• 1998

The effect of paraquat(1,1´-dimethyl-4,4'-bipyridinium) on the gastrin-, somatostatin-, glucagon-, PP-, CCK-8- and serotonin-immunoreactive cells in the stomach and small intestine of developing rat was examined by peroxidase-an-tiperoxidase method. Oral administration of this herbicide(9mg/Kg per day in 0.2ml of D.W) on days 7 to 14 of gestation revealed some difference, such as first appearance and distribution pattern of immunoreactive cells between control and paraquat-treated group. These results suggest that indirectly treated fetuses display a general developmental retardation on enteroendocrine cells differentiation as well as on gastrointestinal maturation

• Environmental Analysis Health and Toxicology
• /
• 제29권
• /
• pp.7.1-7.8
• /
• 2014

Objectives The present study was designed to systematically characterize the denaturation and the renaturation of double stranded DNA (dsDNA), which is suitable for DNA hybridization. Methods A series of physical and chemical denaturation methods were implemented on well-defined 86-bp dsDNA fragment. The degree of each denaturation was measured and the most suitable denaturation method was determined. DNA renaturation tendency was also investigated for the suggested denaturation method. Results Heating, beads mill, and sonication bath did not show any denaturation for 30 minutes. However probe sonication fully denatured DNA in 5 minutes. 1 mol/L sodium hydroxide (alkaline treatment) and 60% dimethyl sulfoxide (DMSO) treatment fully denatured DNA in 2-5 minutes. Conclusions Among all the physical methods applied, the direct probe sonication was the most effective way to denature the DNA fragments. Among chemical methods, 60% DMSO was the most adequate denaturation method since it does not cause full renaturation during DNA hybridization.

• Korean Journal of Food Science and Technology
• /
• 제36권6호
• /
• pp.919-923
• /
• 2004

Effects of adding 0, 2, 4, 6, and 8% freeze-dried kimchi powder (FDKP) on kimchi snack quality were examined. Headspace volatile compounds of 4% FDKP snack, receiving highest overall preference in sensory evaluation results, were analyzed, and 26 compounds were identified, including 13 aldehydes, 3 sulfides, a ketone, an acid, a terpene, and 7 other compounds. Pearson correlation analyses were carried out to determine a correlation between the concentration of FDKP and the amount of each volatile compound. Acetaldehyde, propanal, dimethyl sulfide, dimethyl disulfide, acetic acid, and d-limonene showed correlation coefficients above 0.90; selective ion move (SIM) analysis also showed above 0.97 for highly correlated compounds. Results suggest that these compounds can be used as indicators fur kimchi flavor of FDKP snack.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• 제22권5호
• /
• pp.370-374
• /
• 1989

Volatile components in natural and basic fraction of the steam distillation extraction method from squid during processing were analysed by GC and GC-MS equipped with a fused silica capillary column. Thirty eight compounds were identified; they were 31 compounds from neutral, 7 compounds from basic fraction. The main components flavor of squid were 3-methylthiophene, 2-methyl-2-hexanthiol, 1-penten-3-ol, 3-penten-2-ol, 3-ethyl-1,4-hexadiene, 1-hydroxy-2-propanone, hexenal and benzaldehyde etc.. Especially, (E, E)-3,-5-octadecanal were detected during the boiled. 2,5-dimethyl pyrazine, 2-ethyl-6-pyra-zine, 2,3,5-trimethyl pyrazine and 2-ethyl-3,5-dimethyl pyrazine basic compounds, which have respectively a burnt and roasted odor, are considered to be important for the characteristic basic fraction of squid.

• Bulletin of the Korean Chemical Society
• /
• 제11권6호
• /
• pp.521-527
• /
• 1990

The binding characteristics and analytical applications of anilinium ion complexes with 18-crown-6 were studied by polarography and NMR. First, the electrochemical reduction of the 10 species of mono and dimethylsubstituted anilinium ion complexes with 18-crown-6 as host in methanol are examined. The addition of 18-crown-6 to anilinium guest solution the polarographic waves remain well defined but shifted toward more negative potentials, indicating the complex formation. The values of formation constants, log Κ for 10 species of methylsubstituted anilinium ion complexes with 18-crown-6 varies from 2.7 to 4.8 in methanol at $25^{\circ}C$. The stability order of complexes for 18-crown-6 is anilinilum > 4-methyl > 3,4-dimethyl > 3-methyl > 3,5-dimethyl > 2,4-dimethyl > 2,5-dimethyl > 2,3-dimethyl > 2-methyl > 2,6-dimethylanilinium ion. The steric hindrance shows significant effect. Second, Proton NMR was used to elucidate their interaction characteristics. From the results of so called NMR titration techniques, the behaviors of binding sites on complexation, and the stoichiometry and stability order of complex were obtained. And the later results show the satisfactory agreement with the quantitative values obtained by polarography. Finally, the individual determinations of anilinium ion mixtures were also accomplished by addition of 18-crown-6. In some mixtures of methyl or dimethylanilinium ions the reduction peaks of differential pulse method appeared into one unresolved wave attributed to the small difference of half-wave potential, ${\Delta}E_{1/2}$. In the presence of 18-crown-6, the polarographic waves were resolved into individual maxima because of the shift toward more negative direction by the difference of selectivity of anilinium ions with 18-crown-6. It may be concluded that quantitative analysis of methylanilinium ion mixture make possible because the half-wave potential shift by the selectivity difference due to the steric hindrance between methyl group and 18-crown-6 on complexation.

• Bulletin of the Korean Chemical Society
• /
• 제34권6호
• /
• pp.1673-1678
• /
• 2013

Lumazine protein is a member of the riboflavin synthase superfamily and the intense fluorescence is caused by non-covalently bound to 6,7-dimethyl 8-ribityllumazine. To figure out the binding modes and the structure of the N-terminal domain of lumazine protein, the wild type of protein extending to amino acid 118 (N-LumP 118 Wt) and mutants of N-LumP 118 V41W, S48W, T50W, D64W, and A66W from Photobacterium leiognathi were purified. The biochemical properties of the wild type and mutants of N-LumP 118 proteins were analyzed by absorbance and fluorescence spectroscope. The peak of absorbance and fluorescence of lumazine ligand were shifted to longer wavelength on binding to N-LumPs. The observed absorbance value at 410 nm of lumazine bound to N-LumP 118 proteins indicate that one mole of N-LumP 118 proteins bind to one mole of ligand of lumazine. Fluorescence analysis show that the maximum peak of fluorescence of N-LumP S48W was shifted to the longest wavelength by binding with 6,7-dimethyl 8-ribityllumazine and was shown to the greatest quench effect by acrylamide among all tryptophan mutants.

• Journal of the Korean Chemical Society
• /
• 제41권11호
• /
• pp.586-589
• /
• 1997

1,2,3,4,5,6-Hexaalkyl-1,4-dibora-2-cyclohexene was not produced by the general preparation method in our laboratory because of difficulties in the preparation of $B_2Cl_4.$ 2,3-Dietyl-1,4,5,6-tetramethyl-1,4-dibora-2-cyclohexene, 2 was synthesized by the reduction-oxidation reaction of potassium and methyliodide from 1,4-dimethyl-2,3-diethyl-1,4-dibora-2-cyclohexene, 1 as a substrate. Cobalt sandwich-complexes, 6, 7 and 8 were synthesized by the reaction of 2,3-diethyl-1,4,5,6-tetramethyl-1,4-dibora-2-cyclohexene with $({\eta}5-C_5H_5Co(C_2H_4)_2.$.

• YAKHAK HOEJI
• /
• 제40권1호
• /
• pp.19-24
• /
• 1996

The 6,7-dichloroquinolone-5,8-dione(I) was reacted with ethyl acetoacetate in the presence of sodium ethoxide to yield 6-(${\alpha}$-acetyl-${\alpha$-ethoxycarbonyl-methyl)-7-chloro-quin oline-5,8-dione(II). When this compound II was reacted with some alkylamine (methylamine, ethylamine, propylamine, isopropylamine, cyclopropylamine, methoxyethylamine, ethanolamine, benzylamine, furfurylamine), 1N-alkyl-2-methyl-3-ethoxycarbonyl-pyridino(2,3f)-indole-4,9-dione(IIIa-i) were obtained via intramolecular cyclization.

• YAKHAK HOEJI
• /
• 제44권3호
• /
• pp.263-271
• /
• 2000

In an attempt to develop an injectable form of practically insoluble biphenyl dimethyl dicarboxylate (DDB), the effect of various vehicles, cosolvents and hydrotropic agents was investigated. It was found that polyethylene glycol (PEG) 400 revealed the best solvency toward DDB (17.7 mg/ml at $37^{\circ}C$), and decreasing order of the solubility was as follows: PEG 400>PEG 300>diethylene glycol monoethyl ether (DGME)>PEG-8 glyceryl caprylate/caprate. Among the hydrotropes used, sodium salicylate, sodium benzoate and nicotinamide were effective in increasing the solubility in water. The solubility of DDB in 2 M sodium salicylate, sodium benzoate and nicotinamide solutions was increased 44.3, 23.5 and 44.0 times than that in water, respectively. The addition of sodium salicylate and sodium benzoate to PEG 300-water PEG 400-water and DGME-water cosolvents remarkably increased the solubility of DDB, and significantly retarded precipitate formation when mixed with water Hemolytic properties of DDB injections (2 mg/4~10 ml) in PEG 300-water or DGME-water (60:40 v/v) cosolvents containing sodium benzoate (0.14~0.35 M) were very low. It was concluded from the results that these solutions would be applied to the design of new DDB injections.