• Journal of Plant Biology
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• 제12권1호
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• pp.1-6
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• 1969

General components, free sugars, and free amino acids about Zostera marina which is much distributing and producing along the coastlines of Korea have been separated and identified through Ion exchange resin and Paper chromatography method. So distrigushed are sugars contained that this was quantitated by Bertrand method. 1) The result of the general component analysis of Zostera marina shows that there are much free sugars. 2) According to Bertrand method sugar containment quantitated from terrestrial stem and subterranean stem on Po-hang and Ko-hung areas is much more in terrestrial stem than subterranean stem. 3) Seven kinds of sugars are used in experiments(Table 2) among there glucose, fructose and sucrose which keep the sweetness are very much contained. 4) Shown in Fig. 3 ten kinds of free amino acids inspected from experimental liquid by Paper chromatography are separated, which are known, and one spot which in unknown is additionally separated, and in which four kinds of essential amino acid to nutrient are contained.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.501-504
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• 2000

The purification of a thermostable esterase expressed in Escherichia coli was investigated using thermoprecipitation of unclarified cell homogenates followed by after applying the heat-treated lysate to phenyl-sepharose column, and elution with detergent. Heat treatment at $70^{cdot}C$ was capable of removing to E. coli proteins. Specially, the thermoprecipitation with 15% polyethylene glycol 8000 can remove host proteins and nucleic acids efficiently. Various detergents were used to recover the esterase, which was strongly bound to phenyl-sepharose resin. Triton X-100, non-ionic detergent, was found to be the most efficient of all tested detergents.

• 미생물학회지
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• 제6권2호
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• pp.63-67
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• 1968

Total carbohydrates, amino acids and peptide-like substances in two kinds of Korean lager beers have been analyzed by the calorimetric method of Dreywood's anthrone reagent and Fowden's ninhydrin reagent. The samples were fractionated with column of ion-exchange resin. The experimental results are as follows; 1. Amounts of non-hydrolyzed carbohydrates in the part of column processed is 1. 82% and 1. 96 % (the value was measured by Bertrand's method). But the amounts of those measured by Dreywood's anthrone method are 5.57% and 4.25%, this values are much more than those of Bertrand's method. 2. It can be estimated the amounts of gum and dextrin are 3.75% and 3.30% in both two beers, by comparison of samples with the above mentioned two method. 3. The amounts of carbohydrates by anthrone reagent in acid-hydrolyzed beers are much increased than those of non-hydrolyzed, so it is suggested the presence of polymer carbohydrates which couldn't be detected by Bertrand's method. 4. Total amounts of amino acids are 0.015% and 0.025% (as glycine) in non-hydrolyzed beers measured by ninhydrine color reaction method, on the other hand the amount of amino acids in acid hydrolyzed beers are 0.06% and 0.056%, this is much more than those of nonhydrolysis. The different amounts means that of peptide-like substances. 5. It is necessary to determine the constituent of amino acid for the better taste of beer, and also it is desirable to check the role of carbohydrates in the course of fermentation, mashing and on lager beer for effective utilization of carbohydrate materials to eliminate the losses.

• 한국식품영양학회지
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• 제13권6호
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• pp.534-538
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• 2000

대두유를 기초로 한 튀김유에 capsicum, butter flavor, 규소수지를 각각 0.20, 0.15%($\omega$/$\omega$) 및 10ppm 처리하여 가열안정성의 향상 및 육두향 약화에 효과가 있는 것으로 확인되었다. 즉, capsicum과 규소수지를 병행처리한 튀김유는 185$\pm$2$^{\circ}C$의 온도조건 하에서 3시간 동안 연속적으로 열처리할 경우 AV 및 SP가 각각 무처리군의 0.385, 22$0^{\circ}C$에 비하여 크게 향상된 0.301, 232$^{\circ}C$를 나타내었다. 이러한 효과는 capsicum의 항산화 효과와 함께 소포제의 일종인 규소수지의 작용에 따라 가열처리에 따른 튀김유의 표면적 팽창을 방지하여 유리지방산생성 및 연기발생을 억제한데 따른 효과인 것으로 판단되었다. 또한, 0.15%($\omega$/$\omega$)의 butter flavor처리에 따라 튀김유 및 튀김물에서 발생하는 육두향 및 기름타는 냄새를 막아주는 효과가 인정되어 새로운 형태의 튀김유 제품 생산이 가능할 것으로 기대되었다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.188-194
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• 2015

Objectives: This study evaluated the effect of lactic acid and acetic acid on the microhardness of a silorane-based composite compared to two methacrylate-based composite resins. Materials and Methods: Thirty disc-shaped specimens each were fabricated of Filtek P90, Filtek Z250 and Filtek Z350XT. After measuring of Vickers microhardness, they were randomly divided into 3 subgroups (n = 10) and immersed in lactic acid, acetic acid or distilled water. Microhardness was measured after 48 hr and 7 day of immersion. Data were analyzed using repeated measures ANOVA (p < 0.05). The surfaces of two additional specimens were evaluated using a scanning electron microscope (SEM) before and after immersion. Results: All groups showed a reduction in microhardness after 7 day of immersion (p < 0.001). At baseline and 7 day, the microhardness of Z250 was the greatest, followed by Z350 and P90 (p < 0.001). At 48 hr, the microhardness values of Z250 and Z350 were greater than P90 (p < 0.001 for both), but those of Z250 and Z350 were not significantly different (p = 0.095). Also, the effect of storage media on microhardness was not significant at baseline, but significant at 48 hr and after 7 day (p = 0.001 and p < 0.001, respectively). Lactic acid had the greatest effect. Conclusions: The microhardness of composites decreased after 7 day of immersion. The microhardness of P90 was lower than that of other composites. Lactic acid caused a greater reduction in microhardness compared to other solutions.

• 한국식품과학회지
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• 제11권2호
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• pp.77-80
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• 1979

녹차중(綠茶中)의 L-ascorbic acid를 정량(定量)함에 있어서 흔히 사용되고 있는 DNP법(法)을 적용할 때 불순물(不純物)에 의한 방해(妨害)여부와 그의 제거방법(除去方法)에 대하여 검토(檢討)한 결과(結果)는 다음과 같다. 즉, DNP법(法)으로 AsA를 측정시 ethyl glyoxal, diacetyl, caffeine둥 불순물질 및 아미노산(酸)들이 방해하였으며, 이들 물질을 제거하는 수단으로 브롬산화(酸化)후 o-phenylenediamine을 반응시킨 다음 chloroform으로 추출제거(抽出除去)하고 Amberlite $IR-120(H^{+})$로 아미노산(酸)을 제거(除去)한 후에 DNP법(法)으로 비색정양(比色定量)하면 L-ascorbic acid 함량(含量)을 정확히 측정(測定)할 수 있었다. 또한 분석소요시간(分析所要時間)이 TLC법(法)에 비해서 현저히 단축되고 재현성(再現性)도 좋아서 녹차중(綠茶中)의 ascorbic acid 정량(定量)에는 본법(本法)이 적합함을 확인하였다.

• Archives of Pharmacal Research
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• 제18권4호
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• pp.224-230
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• 1995

Recently, many attempts have been made to use hydrogels of various polymers as delivery systems of various drugs and bioactive materials to prolong and control their phamacological activities. In this study, we have evaluated the physico-chemical properties of methacrylic acid-methyacrylic acid methyl ester copolymer 9Eudispert mv)m a acrylic resin hydorgel, and its application to transdermal delivery system. In the dissolution tests, the release rate of salicylic acid (SA) and sodium salicylate (SOd. SA) were faster than lidocain (LD) and lidocain-HCl(LD-HCl). As the concentration of Eudispert mv polymer increased, the extensibility of Eudispert mu hydrogel decreased, whereas the swelling ratio increased. The more NaOH and polymer concentration increased, the more osmotic pressure linearly increased. The skin permeation of Sod. SA, an acidic model drug, was remarkably enhanced by Eudispert mv hydrogel. All fatty acids, except for Sod. glycolate, dramatically increased the skin permeation flux in Eudispert mu hydrogel containing LD-Hcl, a basic model drug. Consequently, it is suggested that Eudispert mv hydrogel may be used as potential transdermal delivery vehicle.

• 대한화학회지
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• 제30권5호
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• pp.449-455
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• 1986

각종 무수금속염화물을 양이온 교환수지(PK 212)와 같이 이황화탄소 용매속에서 반응시켜 고분자 금속콤플렉스 ${\circled{P}}-AlC_3,\;{\circled{P}}>-FeCl_3,\;{\circled{P}}-SbCl_5,\;{\circled{P}}-SnCl_4,\;{\circled{P}}- ZnCl_2$들을 각각 합성하여 이들의 표면과 절단면을 scanning electron probe microanalyzer로 관찰하였다. 합성된 고분자 금속콤플렉스를 각종 이염기성산과 알코올의 에스테르화 반응에 촉매로 이용하여 고분자 금속콤플렉스의 촉매효과를 비교 검토한 결과 이염기성 카르복실산의 에스테르화 반응에 있어서 고분자 금속콤플렉스들은 유용한 촉매임을 확인하였다.

• 한국식품영양과학회지
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• 제3권1호
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• pp.69-76
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• 1974

The method of amino acid sequence determination from the C-terminal amino acid is proposed and mass spectrometric identification of thiohydantoins described previously. In this paper was discussed the fragmentation of thiohydantoin-ring by deutero substitution and model tripeptide have been degraded through three stages each, with interpretable results. The conditions employed in this method are mild enough for biological materials. The main features of the method are the following. 1. Thiohydantoins were formed in a non-aqueous medium a mixture of acetic anhydride, acetic acid and ammonium thiocyanate. 2. Mass sepectra of thiohydantoins derived from 20 amino acids were obtained with a mass spectrometer, JEOL model JMS-06H. 3. Cleavage of peptidyl thiohydantoin was made with an acidic from of a cation-exchange resin. (Amberlite IR-120) 4. Separation of the cleaved thiohydantoin and the parent peptide less one amino acid moiety was made by chromatography on a Sephadex G-10 column. 5. The peptide fraction was concentrated by freezedrying. 6. Thiohydantoin derivative of carboxyl terminal amino acid residue was introduced with a direct inlet probe in methanol solution.

• 폴리머
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• 제37권3호
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• pp.294-301
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• 2013

Polymersomes made of biodegradable triblock copolymers based on poly(fumaric acid-co-sebacoyl chloride)/PEG (PEG-co-P(FA/SC)-co-PEG) were prepared and studied in aqueous solutions. TEM confirmed the formation of vesicles in aqueous media. Aggregation behavior of the copolymers was studied by fluorescence spectroscopy of 8-anilino-1-naphthalenesulfonic acid, and the critical aggregation concentration (c.a.c.) of the copolymer was found to be ${\sim}26.2{\mu}M$ indicating desirable stability of the vesicles. Dynamic light scattering revealed that the size of the vesicles was distributed within the range of 170-270 nm. Turbidity measurements confirmed the relative short-term stability of the polymersomes. Carboxyfluorescein, a hydrophilic compound, was simply encapsulated in the vesicles during polymersome preparation. The release of encapsulant from the polymersomes at 25 and $37^{\circ}C$ lasted about 3 weeks, and the rate of release followed a first-order kinetics. The release is speculated to be primarily carried out through diffusion. These results confirm that these polymersomes are promising as controlled-release carriers of various drugs.