• 한국식품영양과학회지
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• 제22권2호
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• pp.246-252
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• 1993

Melanoidins, as brown colored polymers, are formed through the diversified reaction systems of Maillard type and other reactions. Melanoidins are important components in relation to food quality and also are known to have antioxidative, mutagenic and antimutagenic activities. Since these aspects have been extensively reviwed elsewhere, only the recent studies regarding to their antioxidative and antimutagenic activities are discussed in this review. Even though their mechanisms are not clearly identified, melanoidins or specific fractions isolated from their mixtures have shown varied antioxidative activities depending on the reaction systems and reaction conditions. Those activities presumely are derived from the complex functional properties of hydrogen / electron donors and metal chelating power, which are originated from their reductone structure and others. It is considered that pyrolysate and other mutagens are formed by the given conditions in some cases during browning reaction, whereas melanoidins and their fractions have antimutagenic effects on chemical and other mutagens. There are positive correlationship among the color intensity, antioxidative activity and antimutagenicity of melanoidins or their fractions. These suggest that the antimutagenicity of melanoidins could be attributed to their antioxidative properties, however, it might also be due to other factors, because the relevant responses for antimutagenicity are very complicate and not clear. Accordingly, further studies are required to determine the actual acitivities and mechanisms involved in antioxidation and (anti)mutagenicity of melanoidins by reaction systems / conditions and by the isolated fractions. And also, additional studies are needed to evaluate the applications of melanoidins and their relevant effects to food and human health.

• BMB Reports
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• 제40권2호
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• pp.163-171
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• 2007

Functional elements of the conserved helix 7 in the poreforming domain of the Bacillus thuringiensis Cry $\delta$- endotoxins have not yet been clearly identified. Here, we initially performed alanine substitutions of four highly conserved aromatic residues, $Trp^{243}$, $Phe^{246}$, $Tyr^{249}$ and $Phe^{264}$, in helix 7 of the Cry4Ba mosquito-larvicidal protein. All mutant toxins were overexpressed in Escherichia coli as 130-kDa protoxins at levels comparable to the wild-type. Bioassays against Stegomyia aegypti mosquito larvae revealed that only W243A, Y249A or F264A mutant toxins displayed a dramatic decrease in toxicity. Further mutagenic analysis showed that replacements with an aromatic residue particularly at $Tyr^{249}$ and $Phe^{264}$ still retained the high-level toxin activity. In addition, a nearly complete loss in larvicidal activity was found for Y249L/F264L or F264A/ Y249A double mutants, confirming the involvement in toxicity of both aromatic residues which face towards the same direction. Furthermore, the Y249L/F264L mutant was found to be structurally stable upon toxin solubilisation and trypsin digestion, albeit a small change in the circular dichroism spectrum. Altogether, the present study provides for the first time an insight into the highly conserved aromaticity of $Tyr^{249}$ and $Phe^{264}$ within helix 7 playing an important role in larvicidal activity of the Cry4Ba toxin.

• 한국식품영양과학회지
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• 제28권3호
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• pp.599-606
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• 1999

Water extracts of persimmon leaf tea(PLTE), green tea(GTE) and oolong tea(OTE), at the con centration used for human consumption, were examined for inhibitory effects on the mutagenicity of major classes of dietary and environmental mutagens including indirect acting mutagens, B[ ]P (benzo[ ]pyrene), IQ(2 amino 3 methylimidazo[4,5 f]quinoline), 2 AA(2 aminoanthracene) in the presence of S9 mix and direct acting mutagen, 4 NQO(4 nitroquinoline 1 oxide) without S9 mix, using the modified Ames Salmonella/microsome assay. PLTE, GTE and OTE showed very potent and concentration dependent antimutagenic effects against indirect acting mutagens B[ ]P and IQ. At the maximum concentration(16,200 g/plate) of each tea extract, number of colonies decreased in a dose dependent manner up to 82~100%. Similar inhibition of PLTE, GTE and OTE were seen at higher concentration in the mutagenicity of the 2 AA following an initial increase in the activity at lower concentration. However, the mutagenicity of the direct acting mutagen 4 NQO were not suppressed at lower concentration of the three tea extracts, and higher concentration of the tea extracts enhanced mutagenic activity of the mutagen. There were no differences in the mode of antimutagenesis between PLTE, GTE, and OTE, in both Salmonella typhimurium TA98 and TA100 strains against the same mutagen. In conclusion, the water extracts of persimmon leaf tea, green tea and oolong tea possess marked antimutagenic potential against a variety of important dietary and environmental indirect acting mutagens, but the activity was not observed against the direct acting mutagens. These results suggest that the mode of inhibitory action may not have resulted from direct interaction between tea extracts and the mutagens, but rather from indirect metabolic inactivation of mutagens by tea extracts.

• 한국식품위생안전성학회지
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• 제24권1호
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• pp.46-49
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• 2009

4-nitroquinoline 1-oxide (4-NQO)와 N-methyl-N-nitro-N'-nitrosoguanidinein (MNNG)에 의해 유도된 돌연변이원성에 대한 결명자 물 추출물의 억제효과를 E. coli PQ37 이용한 SOS Chromotest법으로 검색하였다. $100{\mu}g$/assay 농도에서 4-NQO와 MNNG의 변이원성에 대한 결명자 물 추출물의 변이원성 억제 효과는 27.5 및 40%로 나타났다. 결명자 물 추출물을 메탄을 가용성 부분과 메탄을 불용성 부분으로 분리하여 4-NQO와 MNNG의 변이원성에 대한 억제효과를 검색한 결과 메탄을 가용성 부분이 더 강한 효과를 나타내었다. 따라서 결명자 메탄을 가용성 부분을 에틸아세테이트, 부탄을 그리고 물로 각각 분획하여, 4-NQO 및 MNNG에 대한 돌연변이 억제효과를 검색한 결과 물 분획물은 각각 19.0, 및 23.0% 억제효과로 가장 강하게 나타내었으며, MNNG의 변이원성에 대한 억제효과가 4-NQO의 변이원성에 대한 억제효과보다 더 강하게 나타남을 확인하였다. 결명자 열수추출물의 메탄을 가용성부분의 물 분획물의 농도를 assay당 1.0, 10, 100 및 $250{\mu}g$으로 증가시켰을 경우, 항돌연변이 효과는 각각 8.0%, 12.0%, 25.5%및 43.0%로 나타났다. 이러한 결과로부터, 결명자 물 분획물은 MNNG의 변이원성에 대하여 용량 의존적 억제효과를 나타냄을 확인하였다.

• 한국식품과학회지
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• 제32권6호
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• pp.1213-1220
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• 2000

가열산화된 유지의 산패도와 돌연변이원성과의 관련성을 알아보고자 대두유를 $180{\pm}3^{\circ}C$에서 48시간 동안 가열산화시키면서 0, 8, 16, 24, 32, 40, 48시간 후의 유지시료와 여기서 분획한 산화물 및 비산화물을 대상으로 Salmonella typimurium 변이균주 중 구조이동형(frame shift) 변이균주인 TA98, TA1537과 염기치환형(base-pair substituent) 변이균주인 TA100, TA1535 및 TA102를 사용하여 Ames test를 수행한 결과는 다음과 같다. $180{\pm}3^{\circ}C$에서 48시간 가열산화된 대두유의 가열시간에 따른 돌연변이원성을 조사했을 때 직접법 [-S9] 및 대사활성화법 [+S9] 모두에서 돌연변이원성이 인정되지 않았다. 또한 $180{\pm}3^{\circ}C$에서 가열산화된 대두유를 산화물 및 비산화물로 분리하여 돌연변이원성을 조사한 결과 가열 16시간 및 24시간 후의 산화 물질에서 돌연변이 활성이 나타났다.

• Applied Biological Chemistry
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• 제31권1호
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• pp.38-45
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• 1988

10종류(種類)의 산채류가열즙(山菜類加熱汁)에 대한 돌연변이원성(突然變異原性)을 Spore rec-assay, Ames test 그리고 DNA 절단실험(切斷實驗)으로 검토(檢討)하였으며 가열즙(加熱汁)의 조제(調製)는 $100^{\circ}C$에서 20분간 가열하여 가열즙(加熱汁)을 얻었다. Spore rec-assay 결과 10종류(種類)의 시료(試料)모두 변이원성(變異原性)은 없었으며 금속이온의 영향에서 소리쟁이가열즙은 $Pb^{2+}$, 곰취와 참나물가열즙의 경우는 $Zn^{2+}$의 존재하에서 변이원성을 나타내었다. Ames 시험과 DNA 절단시험에서도 시료모두 변이원성은 없었으며 DNA 절단(切斷)시험에서는 곰취, 머위, 잔대, 개미취가열즙의 경우는 25mM $Cu^{2+}$ 공존하에서 절단활성(切斷活性)이 촉진되었다. 그러나 두릅, 원추리, 잔대, 참나물 그리고 참취가열즙(加熱汁)은 $Fe^{2+}$의 공존시 DNA 절단활성(切斷活性)을 억제(抑制)시키는 결과(結果)를 얻었다. Benzo${\alpha}$pyrene에 대한 돌연변이(突然變異) 억제작용(抑制作用)에서는 시료(試料) 모두 농도증가(濃度增加)에 따라 강(强)한 변이원(變異原) 억제작용(抑制作用)을 나타내었다.

• Applied Biological Chemistry
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• 제42권4호
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• pp.344-350
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• 1999

130종의 식물성 한약재에서 제조한 열수 추출물의 변이원성, 항변이원성 및 세포독성을 측정하였다. 세포내재성 alkaline phosphatase의 활성을 지표로 한약재가 지시세포인 E. coli PQ37의 성장에 미치는 영향을 조사한 결과, 연교(Forsythia koreana Nakai)를 포함한 14종류의 시료자체에서 세포독성이 강하게 나타난 반면, 속단(Phlomis umbrosa Turcz.)등 22종의 시료에서는 세포성장을 촉진하는 활성이 나타났다. SOS chromotest기법을 이용하여 한약재가 가지는 변이원성 및 항변이원성을 조사한 결과, 연교(Forsythia koreana Nakai)와 황련(Coptis japonica Nakai)을 포함한 36종의 시료에서 돌연변이를 유발시키는 능력이 나타난 반면, 산사(Crataegus pinnatifida Bunge)를 포함한 12종의 한약재에서 뚜렷한 항변이원 활성이 검정되었다.

• 대한치과기공학회지
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• 제22권1호
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• pp.145-152
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• 2000

In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.

• 동의생리병리학회지
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• 제25권3호
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• pp.425-430
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• 2011

This study evaluated the effect of extraction conditions of yam (Dioscorea aimadoimo) on antioxidant, moisturizing, collagenase activity, proliferation, and migration. Yam has been recognized as a healthy food due to its various biological activities, such as anti-obesity, anti-constipation, anti-mutagenic activities, as well as its ability to decrease blood glucose and cholesterol levels. Electron donating ability of high temperature ethanol extract of Dioscorea aimadoimo (HDA) had shown 70.6% at 400 mg/ml, and low temperature ethanol extract of Dioscorea aimadoimo (LDA) had shown 40% at 400 mg/ml. SOD-like activities of LDA and HDA were 23% and 34% at 400 mg/ml respectively. LDA significantly reduced the activity of collagenase in a dose-dependent manner, which was higher than HDA. The water contents in LDA-treated skin and HDA-treated skin were increased by 45.63% and 38.65% than the placebo cream respectively. The cellular proliferation of human dermal fibroblast neonatal (HDFn) was evaluated by MTT and cell migration assay. Compared to control, the cell proliferation was elevated to 109.7% and 114% by the treatment of LDA and HDA respectively at the concentration of 200 mg/ml. In addition, LDA and HDA were induced cell migration in HDFn. Our study suggests that LDA and HDA should be a very useful cosmetic ingredient, as anti-aging and skin moisturizer.

• Archives of Pharmacal Research
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• 제18권6호
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• pp.415-422
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• 1995

Twenty-four flavones were synthesized with various hydroxyl and/or methoxyl groups on A and B rings. Their antimutagenic properties were evaluated against ben:w(a)pyrene (BaP) and a pool of mutagenic urine concentrate (U) using a modified liquid incubation method of Ames test. The tester strain was Salmonella typhimurium TA98+S9 Mix. The antimutagenic activities were calculated by non linear regression analysis and the doses of flavones (in nmoles) required for a 50% reduction of induced revertants with BaP and U were defined as the inhibition doses (TEX>$ID_{508}{\;}and{\;}ID_{508}$ respectively). Seventeen flavones possessed significant antimutagenic activity against BaP. $ID_{508}$ ranged from 15.1 nmoles (F22) to 1000.6 nmoles (F13). Eighteen f1avones showed significant antimutagenic activity against U. $ID_{50U}$ ranged from 23.5 nmoles (F22) to 354.6 nmoles (F3). The 2',3',4'-trihydroxyflavone (F22, $ID_{508}=15.1$ nmoles, $ID_{50U}=23.5$ nmoles) and the 2',3',4',7-tetrahydroxyflavone (F20, $ID_{508}=37.8$ nmoles; $ID_{50U}=62.3$ nmoles) had antimutagenic activities similar to those of chlorophyllin ($ID_{508}=19.6$ nmoles and $ID_{50U}=44.2$ nmoles) and were evaluated against B(alP 7,8-dihydrodiol-9,10-epoxide. Against this last mutagen, the flavones which included three OH in B ring showed the highest activity and this property seemed independent of the substituent groups on A ring.