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        검색결과 5

        2.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the total polyphenol, total flavonoid and the antioxidant activity in different origin and parts of Moringa olerifera cultivated in Cheorwon. The extraction yield from leaf, root and stem were 25.5, 23.0, 12.3%, respectively. The total polyphenol content was high in the leaf extracts (15.77 mg/g) followed by root extracts (11.23 mg/g) and stem extracts (3.50 mg/g) but the difference of origin was not observed. The total flavonoid content was high in the leaf extracts (14.78 mg/g) followed by stem (1.36 mg/g) and root (1.14 mg/g). The total flavonoid content of Philippines and Thailand leaf were statistically high compared to india leaf. The DPPH radical scavenging activity was high in the leaf extracts at the 1 mg/ml, 0.25 mg/ml but the difference of origin was not observed. The DPPH radical scavenging activity may be attributed to the presence of several compounds such as polyphenol and flavonoid. Hence consumption of diet supplemented with Moringa olerifera leaves could protect the human against diseases induced by oxidative stress.
        4,000원
        3.
        1992.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Four novel amphoteric surfactants of N-alkoxyethylcarboxybetaine series were synthesized via Schotten-Baurnman reaction between four alkyl chlorides contaning 10, 12, 14 and 16 carbon atoms in their N-alkyl group and dimethylaminoethanol to give the intermediate products, alkoxyethyldimethylamine, Quaternization of these intermediates was permitted to form 2-(alkoxyethyldimethylarnmonio) acetates, whose structures were identified by elemental analysis. IR spectrophotometry and 1Hnmr spectrometry. The yield of the final products was shown in the range of 74~77% based on the yield of the intermediate products, Surface tension of the aqueous solution of the final products was measured. and the critical micelle concentrations(cmc) were shown in the range of 2.82×10-3~2.67×10-6mol/l, and the surface thension at erne was 35~43dyne/cm. Cmc was lowered gradually by the increase of carbon numbers in N-alkyl ether containing group. The isoelectric point was shown in the range of 4.08~6.03. It showed a tendency to lean toward the acidic site and its range was broadened as increase of the hydrophobic group length. A linear relationship between log erne and the number of carbon atoms(N) in the hydrophobic alkyl chain was shown in the relative equation of log cmc=2.49-0.50N.
        4,000원
        4.
        1991.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Four novel amphoteric surfactants of N-(2-alkylamidoethyl)-N, N-dimethyl ammonioacetates were synthesized. The each reaction between four saturated fatty acids containing 10, 12, 14 and 16 carbon atoms and N, N-dimethylethylene diamine permitted to give the intermediate products, N-(2-alkylamidoethyl)-N, N-dimethylamines. Quaterinzation of these intermediates was permitted to form N-(2-alkylamidoethyl)-N, N-dimethyl, ammonioacetates, whose sturctures were identified by CC, TLC, elemental analysis, IR pectrophotometry and 1HNMR spectrometry. The products yielded from 48% to 58%. The isoelectric points were shown in the range of 4.30~6.64. It showed a tendency to learn to the acidic site and its range was broadened as increase of the hydrophobic group length. Surface tensions of the aqueous solution in the 10-6~10-1mol/l of amidobetaines were measured. and the critical micell concentration(cmc) were shown in the range of 8.37×10-6~8.96×10-2mol/l, and γcmc were reduced to 32.3~38.2 dyne/cm. A linear relationship between log cmc and the number of carbon in the hydrophobic alkyl chain was presented by the formula of log cmc=2.38-0.5n, and the contribution-rate of n on the standard free energy change in micellization ɘ(δG0m)/ɘn, was calulated as -0.5RT.
        4,000원