• Natural Product Sciences
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• 제23권4호
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• pp.247-252
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• 2017

The methylglyoxal (MGO) trapping constituents from onion (Allium cepa L.) peels were investigated using pre-column incubation of MGO and crude extract followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Among major constituents in outer scale of onion, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (2) was more effective MGO scavenger than quercetin (6) and its 4'-glucoside, spiraeoside (3). After 1 h incubation, compound 2 trapped over 90% MGO at a concentration of 0.5 mM under physiological conditions, but compounds 3 and 6 scavenged 45%, 16% MGO, respectively. HPLC-ESI/MS showed that compound 2 trapped two molecules of MGO to form a di-MGO adduct and compounds 3 and 6 captured one molecule of MGO to form mono-MGO adducts, and the positions 6 and 8 of the A ring of flavonoids were major active sites for trapping MGO.

• Journal of Applied Biological Chemistry
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• 제43권2호
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• pp.86-93
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• 2000

An experiment was conducted to obtain the quantitative data on the transformation and loss of applied urea-N in waterlogged soil columns. The soil columns were pre-incubated for 35 days to develop oxidized and reduced soil conditions prior to urea application. After urea application at the rate of $150kg\;N\;ha^{-1}$(29.5 mg N), the amounts of nitrogen which were volatilized, leached, and remained in soil column were measured during 38 days of incubation period. On 2 and 4 days of incubation, 54.1%(15.9 mg N) and 98.4%(29.0mg N) of the applied urea was hydrolyzed, respectively. Most of the applied urea was completely hydrolyzed within 6 days. After urea application, the rates of ammonia volatilization were increased with the floodwater pH when the floodwater pH were higher than 7.0. The maximum rate of ammonia volatilization was $0.3mg\;d^{-1}$ when pH of the floodwater showed maximum value of 7.6. The total amount of volatilized nitrogen was 6.1% (1.8mg N) of the applied urea-N. A 63.2 % (18.6mg N) of the applied urea was remained in soil as $NH_4{^+}-N$ and 28.0% (8.2mg N) of the applied urea was leached as $NH_4{^+}-N$ at the end of the incubation. Amount of $NO_3{^-}-N$ in soil was smaller than 2.0 mg throughout the incubation period. The total amount of $NO_3{^-}-N$ leached was very small, which value was 1.8 mg. It suggested that nitrification process was not significant in waterlogged soil column of this study due to high infiltration rate of urea solution applied to the soil column. Therefore only small amount of $NO_3{^-}-N$ was lost by denitrification and leaching process.

• 한국동물위생학회지
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• 제39권3호
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• pp.167-174
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• 2016

In this study, we analyzed for the changes of low organic compounds during 4 weeks incubation though inoculation of harmful microorganisms on commercial feed. Two percent of overnight cultures of Exiguobacterium acetylicum, Acinetobacter calcoaceticus, Aspergillus flavus and Fusarium graminearum were inoculated in feed, respectively. After adjusting moisture level to 50% for the promotion of feed spoilage, pH was decreased to 4.58~5.03 and microorganism was ranged to $6{\sim}10log_{10}CFU/g$. The compounds were compare between aflatoxin G1 producing feeds and aflatoxin G1 non-producing feeds. Aflatoxins G1 were detected by the immunoaffinity column clean-up method with HPLC-FLD, and were confirmed in samples incoulated by Aspergillus flavus and Acinetobacter calcoaceticus. Koiganal II, cyclohexanol and butadien-one were detected from samples (the non-sterilized inoculated feed) by Aspergillus flavus and Acinetobacter calcoaceticus. Respectively as aflatoxin G1 pre-detected substance, Koiganal II, cyclohexanol and butadien-one may be useful substance for the pre-detection of aflatoxin G1.

• 한국연초학회지
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• 제37권1호
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• pp.18-24
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• 2015

Urinary mutagenicity is widely recognized as a useful biomarker for the assessment of mutagen exposure level in human. In this study, we optimized the several parameters affecting the activity of Urinary mutagenicity using highly sensitive mutation test(microsuspension assay) instead of the conventional Ames test. First of all, we chose YG1024 as a highly sensitive strain from three str ains of Salmonella typhimurium(TA98, TA100, YG1024) using r epr esentative mutation substances, such as Benzo[a]pyrene, 2-Aminonaphthalene, 2-amino-3-methyl-9H-pyrido[2,3-b]indole($MeA{\alpha}C$) and cigarette total particulate matter(TPM). And we established the several kinds of test conditions such as number of bacter ia, concentr ation of metabolic activation system and incubation time for the most sensitive reaction. Also, we optimized efficient pre-treatment method using commercial C18 column. As a r esults, this method was shown a aver age of 94 % recovery value and 13 % relative standard deviation. When we compared the Urinary mutagenicity between several participants, we confirmed that compar ative measurements were possible for different levels of urine mutagenicity. In conclusion, the optimized highly sensitive mutation test to measure the Urinary mutagenicity may be useful in biological monitoring of mutagen exposure level.

• Applied Biological Chemistry
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• 제40권5호
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• pp.375-379
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• 1997

리보즘불활성화 단백질(Ribosome-inactivating protein, RIP)을 생성하는 식물을 탐색하여 그중 호박$(Cucurbita\;moschata\;D_{UCHESNE})$ 잎에서 ammonium sulfate 침전, DE 52-Cellulose, S-Sepharose, FPLC Superose 12 HR, FPLC Mono-S column chromatography에 의하여 ribosome-Inactivating 활성이 있는 단백질(PR 1, PRIP 2)을 분리하였다. 정제된 단백질의 분자량은 SDS-PAGE에서 약 31,000과 30,500인 염기성 단백질로서, 특히 PRIP 1은 열에도 안정하여 $50^{\circ}C$에서 30분간 처리한 경우에도 활성이 유지되었다. 이 단백질들의 ribosome-inactivating 활성을 in vitro translation system에서 측정한 결과 50% 활성저해농도 $(IC_{50})$는 PRIP 1은 0.82nM, PRIP 2은 0.79 nM이었다. PRIP 1과 PRIP 2의 N-말단부분의 아미노산 서열을 분석하여, 이미 밝혀진 리보즘불활성화 단백질들과 아미노산서열의 유사성을 분석해 본 결과, PRIP 1은 Luffa cylindrica에서 분리된 Luffin B 및 Trichosanthes kirilowii Maximowicz에서 분리된 Trichokirin과, PRE 2은 Momordia charantia에서 분리된 Momordin II 및 MAP 30과 유사성이 매우 높았다.