• Polymer(Korea)
• /
• v.39 no.2
• /
• pp.300-310
• /
• 2015

In this study, we modified silica nanoparticles with N-[3-(trimethoxysilyl)propyl]ethylenediamine (TPED) silane coupling agent, which has one primary and one secondary amino groups in a molecule, to introduce amino groups on the silica surface. After modification of silica, we used 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) to introduce methacrylate groups by Michael addition reaction. We found about 30% of N-H groups on the TPED modified silica surface reacted with acrylate groups of AHM compared to about 85% of reaction between N-H groups of pure TPED with acrylate groups of pure AHM. This lower degree of Michael addition reaction for heterogeneous reaction between N-H groups on the solid TPED modified silica and liquid AHM compared to homogeneous reaction between pure liquid TPED and pure liquid AHM may be caused by lower mobility of grafted amino groups of TPED moiety and higher steric hindrance caused by solid silica particles.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.3
• /
• pp.291-294
• /
• 2003

A highly interferent-resistive membrane, poly-5-amino-1-naphthol (poly-5A1N), underlied beneath enzymeembedded poly-1,3-phenylendiamine (poly-m-PD) network for miniturized continuous monitoring glucose sensors. The enzyme layer was prepared from a mixed solution of glucose oxidase (GOx) and m-PD monomer by simple electrolysis. The mass change of poly-5A1N was monitored by electrochemical quartz crystal microbalance (EQCM) in situ and the corresponding thickness was measured. Successive electropolymerization of poly-5A1N and poly-m-PD create a several tens nm-thick bilayer showing excellent selectivity for $H_2O_2$ and low activity loss of immobilized enzymes.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.3
• /
• pp.382-387
• /
• 2001

Characteristics of six commercial samjangs were analyzed such as proximate composition, free amino acids, organic acids and free sugars. Also color, taste and odor were evaluated by 36 panelists. They were composed of moisture content 41.4-48.4%, crude protein 9.2-10.4%, crude fat 2.2-3.4%, pH 5.3-5.7, amino nitrogen 194.0%-375.6 mg% and sodium chloride 7.7-9.1%. Total free amino acids of samjangs were 975.89-2304.98 mg%. Glutamic acid was the highest amino acid among free amino acids as 231.7-788.01 mg%. Proline, arginine, alanine and lysine were higher than other free amino acids while histidine, cystine and methionine were lower than other. Eleven free amino acids including glutamic acid were the highest in samjang (B) which contained more doenjang than any other makers did. Total organic acids were 401.01-640.27 mg%. 69.65-269.07 mg% of succinic acid was the highest among organic acids. Lactic acid was the highest in samjang (F) which was home made. Total free sugars was the highest in samjang (A) which contained more wheat flour than any other makers did it. Glucose was 9.30-23.99% and fructose was nd-2.69%. The result of proximate composition showed a different pattern comparing with that sensory evaluation. Samjang (A) which contained less salt showed the highest overall acceptability while samjang (F) which contained more dark color, more salt was the lowest one among the samples.

• Journal of Photoscience
• /
• v.1 no.2
• /
• pp.131-133
• /
• 1994

Optical spectra of 5-amino-2H-1, 2, 4-thiadiazoline-3-one (AT) and some 2-aroyl-5-aroylamino derivatives are reported. Absorption spectra of 2-aroyl-5-aroylamino derivatives show bathochromic shift due to AT group and other substituents of phenyi ring. Weak emission is observed for some derivatives.

• YAKHAK HOEJI
• /
• v.16 no.2
• /
• pp.85-89
• /
• 1972

4,4-Pentamethylene-1,3-oxazolidine-5-one-2-thione is to be obtained from 1-amino cyclohexane carboxylic acid and thiophosgene, however, it was not isolated because of its unstability. When it was treated with $C_{6}H_{5}NH_{2},$ N-phenyl-(1-aminocyclohexane) carboxylic acid and N-(1-carboxycyclohexyl), N-phenyl thiourea were obtained. When refluxed in $H_{2}O$ at pH 2, pH 12 and neutral condition, the resulting carboxylic compound, being anticipated by us, was 1-aminocyclohexane carboxylic acid. From the above results, we have got the suggestion f the chemical behavior of 4,4-pentamethylene-1,3-oxazolidine-5-one-2-thione and also some informations of the reaction mechanism between 1-aminocyclohexane carboxylic acid and thiophosgene.

• Journal of Food Hygiene and Safety
• /
• v.10 no.3
• /
• pp.133-138
• /
• 1995

In vitro antimutagenic activity of methanol extract from brrwn rice and its physico-chemical characteristics were investigated using Salmonella typhimurium reversion assay and SOS chromotest. Methanol extracts of brown rice were not mutagenic compared with direct and indirect, mutagenicities of 4NQO (4-nitroquinoline oxide), 2NF(2-nitrofluorene), Trp-p-1(3-Amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole), and Trp-p-2(3-Amino-1-methy-5H-pyrido-[4,3-b]indole). Antimutagenic activity against the indirect mutagenicties induced by Trp-p-1, Trp-p-2 and AFB1 (aflatoxin B1) was found in methanol extract. Even though antimutagenic activity showed dose-dependent, it remained constant at inhibition rate ranging 60~90% when the concentration was abov 3mg/plate in the S. typhimurium reversion assay and 0.2~0.6 mg/assay in the SOS chromotest. The antimutagenic activity of the methanol extracts was stable at various pH (2, 7 and 10), temperatures (60, 80 and 10$0^{\circ}C$)and heation times (2, 4, 6, 8, 10 min at 10$0^{\circ}C$).

• Bulletin of the Korean Chemical Society
• /
• v.18 no.6
• /
• pp.653-656
• /
• 1997

The new unsymmetric $N_6$ ligand 1-amino-13-(2-pyridyl)-3,6,9,12-tetraazatridecane (aptatd) containing one pyridyl group has been synthesized and characterized by EA, IR, and NMR. Its proton association constants $(log K_H^n)$ and stability constants $(log K_{ML})$ for Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) ions were determined at 298.1 K and ionic strength 0.100 mol $dm^{-3}$ (KNO₃) in aqueous solution by potentiometry: log $K_H^1$=8.80, log $K_H^2$=8.49, log $K_H^3$=6.84, log $K_H^4$=4.17, log $K_H^5$=3.47; log $K_{ML}(Co^{2+})$=18.00, log $K_{ML}(Ni^{2+})$=21.31, log $K_{ML}(Cu^{2+})$=23.62, log $K_{ML}(Zn^{2+})$=15.60. The X-ray structure of its nickel(Ⅱ) complex [Ni(aptatd)]$(ClO_4)_2$ are reported: orthorhombic space group Pbca, a=15.715(1) Å, b=14.280(2) Å, c=19.443(2) Å, V=4363.4 (9) ų with Z=8. The geometry around nickel is a distorted octahedron with the pyridine nitrogen atom being cis to the nitrogen atom of the terminal primary amine.

• Korean Journal of Microbiology
• /
• v.50 no.1
• /
• pp.73-83
• /
• 2014

The objective of the this study was to investigate the binding capacity and removal ability of lactic acid bacterial strains obtained from Korean soybean paste for mutagenic heterocyclic amines (HCAs) formed during cooking of protein-rich food at high temperature. Among 19 strains identified by carbohydrate fermentation and 16S rRNA sequencing, the live cell or cell-free culture supernatant of Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66, and Lactobacillus plantarum D70 inhibited the mutagenesis caused by either 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) in Salmonella typhimurium TA98 and TA100. The bacterial cells of the isolated strains showed greater binding activity than the pure cell wall, exopolysaccharide, and pepetidoglycan. The carbohydrate moieties of the cell wall or protein molecules on the cell surface have a significant role in binding Trp-P-1 and Trp-P-2, since protease, heating, sodium metaperiodate, or acidic pH treatments significantly (P<0.05) reduced the binding efficacy of the tested bacteria. Addition of metal ions or sodium dodecyl sulfate decreased the binding ability of E. faecium D12, L. acidophilus D38, and E. faecalis D66. Therefore, the binding mechanisms of these strains may consist of ion-exchange and hydrophobic bonds. Especially, the high mutagen binding by L. acidophilus D38 and L. plantarum D70 may reduce the accumulation or absorption of Trp-P-1 and Trp-P-2 in the small intestine via increased excretion of a mutagen-bacteria complex.

• Archives of Pharmacal Research
• /
• v.22 no.5
• /
• pp.491-495
• /
• 1999

In order to examine the effects of N-substituted alkyl group on the anticonvulsant activities of N-Cbz-$\alpha$-aminoglutarimides as novel anticonvulsants with broad spectrum, a series of (R) or (S) N-Cbz-$\alpha$-amino-N-alkylglutarimides (1 and 2) were prepared from the corresponding (R) or (S) N-Cbz-glutamic acid and evaluated for the anticonvulsant activities in the maximal electroshock seizure (MES) test and pentylenetetrazol induced seizure(PTZ) test, including the neurotoxicity. The most potent compound in the MES test was (S) N-Cbz-$\alpha$-amino-N-methylglutarimide($ED_{50}$=36.3 mg/kg, PI=1.7). This compound was also most potent in the PTZ test ($ED_{50}$=12.5 mg/kg, PI=5.0). The order of anticonvulsant activities against the MES test as evaluated form $ED_{50}$ values for (R) series was N-methyl > N-H > N-ethyl > N-allyl ; for the (S) series N-methyl > N-H > N-ethyl > N-alkyl > N-isobutyl compound. Against the PTZ tests, the order of anticonvulsant activities showed similar pattern ; for the (R) series, N-methyl > N-H > N-ethyl > N-allyl ; for the (S) series N-methyl > N-H > N-ethyl > N-allyl > N-isobutyl compound. From the above results, N-substituted alkyl groups were though to play an important role for the anticonvulsant activities of N-Cbz-$\alpha$-amino-N-alkylgutarimides.

• The Journal of Information Technology
• /
• v.9 no.1
• /
• pp.1-7
• /
• 2006

In this paper, we describe a study on the relationship between photographic emulsion manufacture and hardening test of films. The hardeners were prepared by condensation of equimolar amounts of trichlorotriazine with benzene- or naphthalene-based amino or oxy acids at 0 to 5$^{\circ}C$ and at pH 7, and used as hardening agents for gelatin. The hardening test of photographic emulsion was studied at pH 5.5. For example I(R=ONa) had strong hardening properties, I substituted with an aminobenzosulfonate moiety (R=$NHC_6H_4-p-SO_3Me$ where Me = K, Na) was a much weaker gelatin hardener, and when substituted with amino- or oxynaphthalene derivative (II, III) did not harden gelatin at all. Compound with 2 dichlorotriazine groups as IV exhibited strong hardening properties. The hardener can be used in photographic emulsion of film and showed very good hardening effect.