• Journal of Food Hygiene and Safety
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• v.10 no.1
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• pp.1-6
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• 1995

In order to establish the enzyme linked immunosorbent assay(ELISA) of sterigmatocystin produced by Aspergillus versicolor, we experimented and obtained following results. Two of three rabbits which had been immunized with sterigmatocystin-hemiacetal-BSA produced antibodies against sterigmatocystin at 15 weeks. The produced antibodies were specific for sterigmatocystin and sterigmatocystin-hemiacetal but didn't cross react with other sterigmatocystin analogues in a significant degree. DMF : 4% KC1 (18 : 2) mixed solution was most effective to dissolve sterigmatocystin. For the preparation of sample solution to determine sterigmatocystin by ELISA, sample was extracted with CHC13 and dried, than the dried sample was redissolved with 100 ${mu}ell$ DMF + 4% KC1 mixture. 10~1,000 ng/$m\ell$ level of standard sterigmatocystin could be applied to the established ELISA. When artifically contaminated rice were assayed by the ELISA, the average recovery of sterigmatocystin spiked to 25~500 ng/g was 109% (97~116%), and mean interwell coefficient of variation was 21% (11~28%).

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.141-143
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• 2011

Al-SBA-1(Si/Al = 40, 80 and 120) and Al,Mg-SBA-1 (Si/(Al+Mg) = 40 and 80) molecular sieves were synthesized and characterized. Acetalization of n-heptanal with methanol was studied under autogenous pressure between 80 and $150^{\circ}C$. Since protonation of n-heptanal was fast, addition of methanol to the same to formed hemiacetal slowly whereas conversion of hemiacetal to acetal was fast. The catalysts exhibited nearly similar conversion irrespective of their difference in acidity, and all of them showed more than 80 % conversion either at 80 or $100^{\circ}C$. Hence it is evident that the difference in acidity is not so important in differentiating the activity of the catalysts. The large pore size and hydrophilic and hydrophobic properties are suggested to be the main factors that control acetalization.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3423-3424
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• 2014

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.222-222
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• 1994

목적하는 화합물인 2',5'-dihydroxy-3'-무치환 유도체(1)는 uridine을 sodium metaperiodate로 산화하여 dialdehyde를 얻은다음 1,2-dianilinoethane으로 3'-aldehyde만을 선택적으로 보호, 2'-aldehyde를 NaBH$_4$로 환원, alcohol로 하여 deprotection 하므로서 hemiacetal율 얻는다. 이 hemiacetal을 TsSNHHNH$_2$로 처리하여 목적하는(1) 화합물을 얻었으며 2-azido-5-Hydroxy-3'-무치환 유도체(2)는 (1)화합물 합성시 얻은 hemiactal을 출발 물질로 하여 먼저 TBDPSCl로 silyaltion하여 5'-hydroxyl group을 보호하고 TsNHNH$_2$로 3'-위치를 hydrazone으로 한다음 NaB(CNH$_3$로 처리하여 얻은 hydrazide를 NaOAc를 반응시켜 2'-hydroxy-3'-무치환-5'-silyl 유도체를 얻고 또한 2',3'-dihydroxy group을 tosyl화, azido화, 5'-silyl group을 deprotection 하므로서 (2)를 얻었다. 또한 2',3'-dihydroxy-5'-무치환 유도체(4)는 uridine의 2',3'-위치를 먼저 protection, 5'-위치를 benzoyl화 2',3'-deprotection, periodate oxidation하여 얻은 diol을 silyl화 한 다음 5'-위치를 benzoyl화, 2',3'-deprotection, 산화하여 얻은 hemiacetal의 silyl group을 제거한후 primary hydroxyl group만을 선택적으로 silyl화, TsNHNH$_2$, NaB(CN)H$_3$ 및 NaOAc로 처리하므로서 얻은 2'-hydroxy-3'-0-silyl group-5'-무치환 화합물을 tosyl, azido화 한다음 desilylation하여 얻었다. 목적하는(1) 화합물의 diasteromer 인 2',3'-dihydroxy-5'-무치환 유도체(3)는 (4)화합물 합성시 얻은 hemiactal을 key intermediate로 하여 TsNHNH$_2$, NaB(CN)H$_3$ 및 NaOAc로 처리하므로서 얻을수 있었다. 이들 화합물들의 각종 DNA 및 RNA virus에 대한 항 바이러스작용을 검토한 결과 현저한 항 바이러스 작용을 나타내지 않았다.

• Journal of Food Hygiene and Safety
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• v.7 no.1
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• pp.15-22
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• 1992

This study was conducted to determine the potential of grapefruit seed extract to support Aspergillus parasilicus growth and aflatoxin production. The grapefruit seed extract inhibited the growth and aflatoxin production of the fungi in the level of more than 4,000 ppm and 3,000 ppm in the medium, respectively. Grapefruit seed extract appears to block the conversion of acetate, averufin and versiconal acetate into aflatoxin in vitro experiments. The addition of grapefruit seed extract to the feeding experiment systems did not inhibit the incorporation of 14C-labeled versicolorin A, versicolorin A hemiacetal and sterigmatocystin into aflatoxin. In the electron microscopic examination the biocidal action of grapefruit seed extract was related to the disturbance of cell menbrane funtion, inhibiting cellular respiration.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.814-819
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• 2015

The natural crosslinking agent genipin has been applied widely in biomedicines and foods nowadays. Because of the special hemiacetal ring structure in its molecule, it can only be prepared by hydrolysis of geniposide according to biocatalysis. In this research, strategies including aqueous-organic biphasic catalysis and substrate fed-batch mode were adopted to improve the biocatalysis process of genipin. A 10 L ethyl acetate-aqueous biphasic system with geniposide fed-batch led to a satisfying genipin yield. With Fusarium solani ACCC 36223, 15.7 g/l genipin in the ethyl acetate phase was obtained, corresponding to space-time yields of 0.654 g l^-1 h^-1.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.247-250
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• 2012

Raw milk samples (n=28) obtained from milk tanks in 3 dairy plants of different regions and commercial milks (n=100) were collected from six cities. These samples were analyzed for the level of aflatoxin $M_1$ contamination using immunoaffinity columns and high performance liquid chromatography coupled with fluorescent detectors. Confirmation of aflatoxin $M_1$ ($AFM_1$) identified in positive samples was based on the formation of the hemiacetal derivative ($AFM_{2a}$) after derivatization with trifluroacetic acid. The average concentrations of aflatoxin $M_1$ in the raw milks were 25.1 ng/kg, and those values in commercial milks were 29.8 ng/kg. The highest level of aflatoxin $M_1$ in milk was 72.7 ng/kg. These results showed that the contamination of aflatoxin $M_1$ in milks consumed in the Korea was quite low compared to the standard in Korea Food Code (aflatoxin $M_1$ 500 ng/kg).

• Journal of Pharmacopuncture
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• v.3 no.2
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• pp.1-25
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• 2000

We were trying to study the validity of Puffer fish's poison(Tetrodotoxin- TTX) to make a traditional Korean Medical treatment. The following conclusions were made after literary studies. 1. The first record of the puffer fish dates back 2000 years ago in the Chinese text Book of Mountain and Sea and other texts from the similar period. 2. Puffer fish's poison IS known as tetrodotoxin which is an amino perhydroquinazoline compound. It has a chemical formula of $C_{11}H_{17}N_3O_8$ in the hemiacetal structure and has the molecular weight of 319. 3. Tetrodotoxin (TTX) plays a role as potent neurotransmitter blocker by blocking the $Na^+$ -gate channel which hinders the influx of $Na^+$ ion into the cell. 4. Symptoms of the puffer fish poisoning ranges from blunted sense in the lips and tongue, occasional vomiting in the first degree to sudden descending of the blood pressure, apnea, and other critical conditions in the fourth degree. Intoxication of the puffer fish poison progresses at a rapid pace as death may occur after an hour and half up to eight hours in maximum. Typical death occurs after four to six hours. 5. Ways to treat the puffer fish poisoning include gastric irrigation, induce vomiting, purgation, intravenous fluid injection, and correcting electrolytic imbalance and acidosis. In cases of dyspnea, apply oxygen inhalation and conduct artificial respiration. 6. Tetrodotoxin (TTX) may be applied in treating brain disorders, ocular pain, excess pain in the large intestine and ileum, and relieving tension of the skeletal museles, neuralgia, rheumatism, arthritis, and etc. 7. In terms of Oriental medicine, the puffer fish poison has characteristics of sweet, warm, and poisonous. It's known efficacies are to tonify weakness, dispel damp, benefit the lower back, relieve hemorrhoid, kills parasites, remove edema, and so forth. And the puffer fish eggs processed with ginger are said to be effective against tuberculosis and lung cancer, thus, it's validity must be investigated and further research should be followed.