• Toxicological Research
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• 제15권1호
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• pp.95-101
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• 1999

Cytochrome P450 (CYP) 3A4 metabolizes aflatoxin B1 (AFB1) to AFB1-exo-8,9-epoxide (8,9-epoxidation) and aflatoxin Q1 (AFQ1; 3$\alpha$-hydroxylation) simultaneously. We investigated whether each metabolite was formed via its own binding site of CAP3A4 active site. Kinetics of the formation of the two metabolites were sigmoidal and consistent with the kinetics of substrate activation. The HIll model predicted that two substrate binding wites are involved in the oxidationof AFB1 by CYP3A4. Dehydronifedipine, a metabolite of nifedipine generated by CYP3A4, inhibited the formation of AFQ1 without any inhibition in the formation of AFB1-exo-8,9-epoxidation. Dehydronifedipine was found to act as a reversible competitive inhibitor against 3$\alpha$-hydroxylation of AFB1. Vmax and S0.5 of the 8,9-epoxidation were not changed in the presence of 0, 50, or 100 $\mu\textrm{M}$ dehydronifedipine. S0.5 of 3$\alpha$-hydroxylation was increased from 58$\pm$4 $\mu\textrm{M}$ to 111$\pm$8 $\mu\textrm{M}$ in the presence of 100 $\mu\textrm{M}$ nifedipine whereas Vmax was not changed. These results suggest that there exist two independent binding sites in the active site of CAP3A4 . One binding site is responsible for AFB1-exo-8,9-epoxidation and the other is involved in 3$\alpha$-hydroxylation of AFB1. Dehydronifedipine might selectively bind to the site which is responsible for the formation of AFQ1 in the active site of CYP3A4.

• 한국균학회지
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• 제26권4호통권87호
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• pp.487-495
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• 1998

우리 나라에 중요한 식품의 원료인 메주에 대한 균독소($Aflatoxin\;B_1$와 Ochratoxin A) 생성 여부를 인위적인 혹은 자연적인 환경에서 조사하였다. 채집된 메주에서 균을 분리하여 접종함으로, 인위적인 환경인 독소생성 배지와 콩을 이용한 배지를 이용하여 균독소 생성을 관찰하였다. 조선 전통메주에서 채집된 메주 균인 불완전 진균들은 몇 몇 균이 독소를 생성하였으나, 멸균된 날 콩에는 다만 $2{\sim}3$개의 분리균들이 $Aflatoxin\;B_1$와 Ochratoxin A를 분비하였다. 그러나, 언급된 두 개의 균독소가 함께 생성하는 분리균은 관찰되지 않았다. 그러나, 조선 전통메주에서는 어떤 채집된 메주에서도 위의 균독소가 $0.01{\sim}100\;ng$ 범위에서 관찰되지 않았다. 이러한 결과로 메주 제조에 관련된 메주 균에서 털곰팡이(Mucor species)가 메주 제조에 초기에 작용한 균으로 전통 메주의 발효와 균독소 생성과 관계에서 중요한 것으로 사료된다.

• 한국식품영양과학회지
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• 제20권2호
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• pp.156-161
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• 1991

고추가루의 돌연변이유발, 보돌연변이 및 항돌연변이 효과를 검토하기 위해 매운맛의 재래종과 덜 매운맛의 교배종을 극성이 다른 용매로 3분획한 것과 고추의 주요한 매운 성분으로 알려진 capsaicin을 Ames mutagenicity test를 이용하여 연구하였다. 고추가루 추출획분들을 모두 direct한 돌연변이유발성이 없는 것으로 나타났고 MNNG가 존재할 때의 보돌연변이 효과도 나타나지 않았다. 또한 이들은 rat S9이 존재할 때의 indirect한 mutagenicity도 일으키지 않는 결과를 보였다. 고추가루의 주요 매운 성분인 capsaicin도 Aroclor 1254, phenobarbital로 induce시킨 rat S9과 Aroclor 1254로 induce시킨 hamster S9 등의 activation system을 이용하여도 돌연변이유발의 효과는 나타나지 않았다. 그러나 고추가루 추출획분들은 TA100 strain에서 모두 aflatoxin $B_1$의 mutagencity를 오히려 억제시키는 결과를 나타내었는데 이 효과는 고추가루의 첫번째 획분(1st fraction)이 가장 컸었다.

• 한국동물위생학회지
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• 제42권3호
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• pp.127-133
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• 2019

The purpose of this study was to investigate the contamination level of representative mycotoxins that have adverse effects on livestock by using LC-MS/MS method and to utilize the results as basic data for the establishment of quality control system for feed, and to provide information on production and storage. A total of nine mycotoxins, including aflatoxin $B_1$, aflatoxin $B_2$, aflatoxin $G_1$, aflatoxin $G_2$, ochratoxin A, fumonisin $B_1$, fumonisin $B_2$, deoxynivalenol (DON), zearalenone (ZEN) were simultaneously analyzed in LC-MS/MS under ESI positive mode. Fumonisin $B_1$ and fumonisin $B_2$ were detected from 3 cases of 75 forage produced in Incheon area, the detection rate was 4.0%. The detection concentration was 0.01~0.02 mg/kg, which was lower than the domestic recommended limit. Fumonisins were detected in a slightly different manner from the results of mycotoxin studies reported in Korea, which is attributed to the high temperature and dry summer weather of the year. The result of LC-MS/MS method performance of 9 mycotoxins, the recovery of DON was quite low as $41.53{\pm}3.91%$ that is not suitable for simultaneous analysis. This is probably due to that the extract solution used in this study was not suitable for the extraction of DON, along with the characteristics of a very dry forage. For the study of mycotoxins in Incheon area forage for the first time, further investigation is needed for the safe supply of livestock products.

• 농업과학연구
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• 제48권1호
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• pp.73-81
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• 2021

The current study investigated how Saccharomyces cerevisiae ameliorates the adverse effects of aflatoxin on in vitro rumen fermentation. In this study, five groups (T₁: Control [basal feed]; T₂: T₁ + 300 ppb aflatoxin B1 [AFB₁] and T₃, T₄, and T₅: T₂ with 0.05, 0.1, and 0.2% of S. cerevisiae, respectively) were prepared and incubated in vitro. The results revealed that truly degradable dry matter (TDDM), gas production (GP), microbial biomass production (MBP), truly degradable organic matter (TDOM), partitioning factor (PF), total volatile fatty acids (TVFA), acetate (A), propionate (P) and butyrate (B) values in the control group (T₁) were higher (p < 0.05) than those of the AFB₁ fed group (T₂). The A : P ratio in the control group (T₁) was reduced (p < 0.05) when compared to that of the T₂ group. The TDDM, TDOM, GP, TVFA, A, P, and B values of T₃, T₄, and T₅ improved with the increasing levels of S. cerevisiae; however, the values of group T₅ were lower (p < 0.05) than that of the control. The values of MBP, A : P ratio and PF in group T₅ were statistically similar to that of the control. It was concluded that the inclusion of S. cerevisiae (0.05 to 0.20%) to the AFB₁ (300 ppb) contaminated feed partially to completely ameliorated the adverse effects of AFB₁ on the in vitro rumen fermentation parameters.

• 생약학회지
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• 제51권4호
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• pp.270-277
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• 2020

This study analyzed mycotoxins, aflatoxin B1, B2, G1, G2, fumonisin B1, B2, ochratoxin A and zearalenone, using LC-MS/MS and conducted risk assessment on 54 samples of seeds distributed in SeoulYangnyeongsi and the management status of extramural herbal dispensary facility. The matched calibration showed a good linearity as observed in 6 concentration levels(r2>0.999) as a result of method validation applied with Arecae semen. Limits of detection(LOD) and quantification(LOQ) were in the range of 0.02-0.11 ㎍/kg and 0.08-0.34 ㎍/kg, respectively. Recoveries also estimated, ranging from 65.1-99.7% with relative standard deviation(RSD) 0.5-6.3%. As a result of the method on 54 samples, mycotoxins were detected in 16 samples. Among them, two Thujae semen showed a degree of concentration that exceeded the aflatoxin specification. In the risk assessment, the human exposure safety standard values were calculated as ADI(Acceptable Daily Intake) for aflatoxin B1, fumonisin and zearalenone. Ochratoxin A was calculated as PTWI(Provisional Tolerable Weekly Intake). The MOE(Margine of Exposure) of aflatoxin B1 was in the range of 40.36-3536.88. And no items exceeded 100% in %TDI(Tolerable Daily Intake) and %TWI(Tolerable Weekly Intake) of fumonisin, zearalenone and ochratoxin A.

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.202-210
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• 2022

Aflatoxin contamination in rice has been documented in a number of studies, and has a high incidence in Asian countries, and as such, there has been a growing interest in alternative biocontrol strategies to address this issue. In this study, 147 strains of yeasts and yeast-like fungi were screened for their potential to produce volatile organic compounds (VOCs) active against Aspergillus flavus strains that produce aflatoxin B₁ (AFB₁). Five strains within four different genera showed greater than 50% growth inhibition of some strains of A. flavus. These were Anthracocystis sp. DMKU-PAL124, Aureobasidium sp. DMKU-PAL120, Aureobasidium sp. DMKU-PAL144, Rhodotorula sp. DMKU-PAL99, and Solicococcus keelungensis DMKU-PAL84. VOCs produced by these microorganisms ranged from 4 to 14 compounds and included alcohols, alkenes, aromatics, esters and furans. The major VOCs produced by the closely related Aureobasidium strains were found to bedistinct. Moreover, 2-phenylethanol was the most abundant compound generated by Aureobasidium sp. DMKU-PAL120, while methyl benzeneacetate was the major compound emitted from Aureobasidium sp. DMKU-PAL144. On the other hand, 2-methyl-1-butanol and 3-methyl-1-butanol were significant compounds produced by the other three genera. These antagonists apparently inhibited A. flavus sporulation and mycelial development. Additionally, the reduction of the AFB1 in the fungal-contaminated rice grains was observed after co-incubation with these VOC-producing strains and ranged from 37.7 ± 8.3% to 60.3 ± 3.4%. Our findings suggest that these same microorganisms are promising biological control agents for use against aflatoxin-producing fungi in rice and other agricultural products.

• 한국식품과학회지
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• 제42권1호
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• pp.27-32
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• 2010

고시된 아플라톡신 시험법의 정량한계, 검출한계를 개선한 분석법을 유효화하였으며, 개선한 분석법으로 강활, 개자 등의 생약 400개의 시료를 분석하였다. 사군자와 제니 각 1건에서 아플라톡신 $B_1$이 각 $2.3\;{\mu}g$/kg 검출되었으며, 사군자와 대풍자 1건에서 정량한계 미만의 아플라톡신이 검출되었다. 탕제로의 이행률은 아플라톡신 $B_1$의 경우 약 20% 정도의 이행률을 나타냈다. 아플라톡신 $B_1$ 기준치보다 낮게 검출되어 현재까지는 아플라톡신으로부터 안전한 것으로 판단되었다.

• 한국식품위생안전성학회지
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• 제10권2호
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• pp.81-87
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• 1995

Daily exposure of aflatoxin B1 (AFB1) was estimated in foods (rice, barley, soybean, peanut, soysauce, soybean paste) by ELISA (enzyme linked immunosorbent assay) using polyclonal antibody R101. Before ELISA, a simple extraction method was applied for the quantitation of AFB1 in foods using chloroform which showed high recovery (70$\pm$12%). AFB1 levels in foods were 0.32 ng/ml (rice), 0.24ng/ml (barley), 0.22 ng/ml (peanut), 0.30~0.78 ng/ml (soysauce), and 0.2 ng/ml (soybean paste). Based on food consumption, we estimated that Koreans were exposed to AFB1 at the level of 1.86$\pm$0.46 ng/kg/day and liver cancer incidence attributed to AFB1 exposure (assuming that AFB1 as a single hepatocarcinogenic agent) might be calculated to be 13.1 per 100, 000 population. Our data demonstrate that AFB1 levels in foods were below the regulation of 10 ppb in foods and might not be the major risk factor for the high incidence of lover cancer in Korea.

• 한국식품위생안전성학회지
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• 제4권3호
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• pp.165-170
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• 1989

영남지방의 농산물로부터 Aflactoxin 생성균을 분리하기 위해 쌀 59점, 메주 30점, 옥수수 32 점 , 보리 58점, 토양 33점, 땅콩 30점, 대두 45점 및 겉보리 60점을 1989년 3월에서 7월 사이에 수집하였다. 총 342 시료로부터 280종의 Asperigllus속 균주를 분리하였고, 그 중에서 29균주가 형광성을 나타내었으나 4균주가 표준 Aflactoxin과 Rf치가 같은 물질을 생산하여 전체시료의 1.3%가 Aflactoxin 생성균에 오염되어 있음을 알 수 있었고 균학적 성질을 관찰한 결과 4균주 모두 Asp. flavus group으로 추정되었다.