아플라톡신 G₁의 酸化反應에 關한 硏究(第ⅩⅤ報)

김진목,장향동 서울産業大學校 1994 논문집 Vol.40 No.1

아플라톡신 G₁(AFG₁)을 클로로포름 溶媒內에 오존화시킨 酸素 (오존)로 酸化시키면 마지막 푸란고리의 二重結合이 酸化되어 外向 2,3-옥시도(에폭시드)가 얻어졌다. 그리고 이 反應은 -78.5 ℃에서 1時間 遂行하였다. 클로로포름 溶媒는 窒素 가스를 흘려 보내어 除去시키고, 그리고 이때의 殘溜物은 蒸溜에 의하여 分離시켰다. 外向 2,3-옥시드(에폭시드)는 赤外線 分光 光度器(I.R), 水素 및 炭素-13 核 磁氣 共鳴 分光器(PMR & CMR)를 이용하여 構造를 確認하였으며, 가스크로마토그래피 / 質量 分析 分光器 (GC/MS)에 의하여 分子量을 測定하여 各各 確認하였다. The oxidation of aflatoxin G₁(AFG₁) by ozonized oxygen (O₃) in chloroform solvent gave the exo 2, 3-oxide(epoxide) in double bond of the terminal furane ring and this reaction have been carried out 1hr at -78.5℃. The chloroform solvent was removed in a stream of nitrogen and the residue was separated by evaporation. The 2, 3-oxide(epoxide) have been identified by using infrared spectrophotometer (I.R), proton and carbon-13 unclear magnetic resonance spectrometer (PMR & CMR) and determined to molecular weight by gas chromatography/mass spectrometer (GC/MS), respectively.

발암물질인 아플라톡신 G1 에폭시드의 가메탄올 분해에 관한 연구

장향동,류성렬,진주희 한국공업화학회 2000 응용화학 Vol.4 No.1

The methanolysis of anhydrous methyl alcohol (MeOH) with Aflatoxin G₁ (AFG₁) exo-9, 10-epoxide formed predominantly a trans methoxy alcohol (95% over), but the methanolysis of MeOH under acidic conditions with AFG₁ exo-9, 10-epoxide formed a trans methoxy alcohol (84%) and a cis methoxy alcohol (16%). And, the methanolysis of anhydrous MeOH with AFG₁ endo-9, 10-epoxide formed a trans methoxy alcohol (80%), but the methanolysis of MeOH under acidic conditions with AFG₁ endo-9, 10-epoxide formed a cis methoxy alcohol (20%). The methanolysis studies reveal exclusive trans opening of exo-epoxide and under acid conditions, the endo-epoxide formed mixtures of trans and cis(4 : 1) ratio products.

포도로부터 아플라톡신 B₁의 정량분석에 관한 연구(第 ⅩⅧ 報)

정용복,백광균,장향동 서울産業大學校 1997 논문집 Vol.49 No.2

강력한 발암성 물질인 Aflatoxin 화합물 중 독성이 가장 강한 AFB₁의 온도와 상대습도 변화에 따른 생성량을 조사하기 위하여 포도에 Aspergillus flavus KCCM 35078 균을 접종하여 온도는 26℃, 30℃, 34℃, 상대습도는 각각 50%, 60%, 70%, 80%,그리고 배양시간은 72(3일), 96(4일), 120(5일), 144(6일), 168시간(7일) 동안 정치 배양하였다. AFB₁을 Column Chromatography로 정제하였고, TLC를 이용하여 분리하였으며, HPLC와 UV/VIS Spectrophotometer를 사용하여 정량분석 하였다. 분석결과 30℃, 상대습도 80%, 배양시간 168시간(7일) 일 때, 최대 생성량을 보였으며, HPLC로 정량한 경우 24.99ppm, UV/VIS로 정량한 경우 26.84ppm으로 감도의 차이를 보였다. 또한, HPLC와 UV/VIS를 이용하여 정량 분석한 결과에 의하면 약간의 감도의 차이를 보였지만 최대의 생성량은 30℃, 상대습도 80% 및 배양시간 168시간(7일) 이었으며, 최소의 생성량은 26℃, 상대습도 50% 및 배양시간 72시간(3일)일 때이었다. 따라서 온도와 상대습도 변화가 균 성장 및 AFB₁의 생성량에 큰 영향을 주었다. AFB₁의 구조는 각각 질량분석 분광기(Mass), 수소 핵자기 공명 분광기(¹H-NMR) 및 적외선 분광(I.R.)를 이용하여 확인하였다. Aflatoxin B₁(AFB₁) was known to have the strongest poisonous character out of Aflatoxin compunds. To search the production of AFB₁according to the change of temperature and relative humidity, grape inoculated with Aspergillus flavus KCCM 35078 was incubated at 26℃, 30℃, 34℃ and at relative humidity 50%, 60%, 70%, 80% and for incubation time 72. 96, 120, 144, 168 hours. AFB₁ was refined by using Column Chromatography and separated by using Thin Layer Chromatography(TLC). And then it was quantitatively analyzed by using High Performance Liquid Chromatography(HPLC) and Ultra Violet/Visible Spectrophotometer(UV/VIS). The measuring result shows that the highest production appeared at 30℃, relative humidity 80%, and incubation time 168(7 days) hours. The result shows difference of sensitivity that quantitative analysis by using HPLC was 24.99ppm and using UV/VIS was 26.84ppm. The result of the Quantitive analysis by HPLC and UV/VIS shows a little difference of sensitivity. However, the highest production was appeared at 30℃, relative humidity 50% and incubation time 72(3 days) hours and the lowest production was appeared at 26℃, relative humidity 50%, and incubation time 72(3 days) hours. Like that, the change of temperature and relative humidity influenced much the production of AFB₁ and the growth of culture. The structure of AFB₁ was identified by using instrumental analysis methods of Mass, ¹H-NMR, IR respectively.

Aflatoxin B₁의 化學的 脫毒素化에 關한 연구(第Ⅰ報)

長香東 서울産業大學校 논문집 Vol.12 No.1

Aflatoxin B₁was treated with many chemicals, especially bases, acids, oxidizing agents and reducing agents in various concentrations under reflux at atmospheric pressure. Less of fluorescence and change of ?? value on TLC were the principal reaction indicators. Also, aflatoxin B1 was treated with formaldehyde alone and in combination with calcium hydroxide, and the products were evaluated chemically. TLC assays revealed that addition of calcium hydroxide to formaldehyde caused greater inactivation of the toxins than did formaldehyde alone. The reactions appear the olefinic double bond of the terminal furane ring and oxidation involving the phenol formed on opening of the lactone ring.

L- α-alanine의 미셀化를 위한 臨界濃度에 關한 硏究(Ⅵ)

張香東 서울産業大學校 1978 논문집 Vol.11 No.1

The studies on the critical concentrations for Micellization of L- α-alanine The Critical concentrations of L- α-alanine for micellization have been determined by the surface tension measurments in acid and alkali solutions, and also by the dye titration using Rhodamine, 6G in alkali solutions. The critical concentrations for micelle formation obtained by the above two methods shows the good agreement within experimental errors. Since L- α-alanine is an ampholyte, it may aggregate to form the micelles in both acidic and basic media than its isoelectric points. The basic media was found the good for the micelle formation than acidic media. The effect of gegen ions upon critical concentrations for micellization in alkaline media is similar to that expected from the salts effect on critical micelle concentrations.

아플라톡신 B₁의 할로겐화에 關한 硏究(第Ⅵ報)

張香東 서울産業大學校 1984 논문집 Vol.20 No.1

3a,8a-디히드로-[2,3-b]-벤조푸란과 아플라톡신 B₁에 브롬을 반응시킨 末端푸란고리의 二重結合에 附加反應을 일으킨 結果로서 獨點的으로 트란스형의 二브로모化合物을 生成하지만, 이와 反面에 鹽素를 附加反應시키면 트란스- 및 시스-二鹽化物의 混合物을 生成하는 結果가 나타난다. 이와같은 結果物인 二브로모化合物을 原子配列의 持保로서 名名 C-2 및 C-8 位置에서 親核的 置換을 일으킨다. 그러나, 類似한 方法으로 二鹽化物의 置換은 立體持異性을 나타내지 않았다. Bromine reactions of 3a,8a - dihydrofuro-[2,3-b]-benzofuran and aflatoxin B₁results in the addition at double bond of the terminal furane ring to produce exclusively trans-dibromides, whereas addition of chlorine results in mixture of trans-and cis-dichlorides. The resultant dibromides undergo nucleophilic substitution at C-2 or C-8, respectively, with retention of configuration. But the analogous substitution on the dichlorides is not so stereospecific.

Benzyl chloride와 Mercurous nitrate의 反應에 關한 反應速度論的 硏究 (第Ⅳ報)

張香東 서울産業大學校 1976 논문집 Vol.9 No.1

The kinetics of the reaction of m-or p-substituted benzyl chlorides with mercurous nitrate in acetonitrile at 25° were determined by an electric conductivity method. According to a plot of log k against the Hammett substituent constants, C-Cl bond cleavage in benzyl chloride is postulated to be a rate determining step at the SN₂ reaction of benzyl chloride with mercurous nitrate. Both electron-donation substituents and electron-withdrawing substituents quantitatively affected the rate of reaction, but each in a different manner. A mechanistic possibility was proposed to account for the results and some activation parameters were also calculated.

A flatoxin B_1의 化學的 脫毒素化에 關한 硏究(第Ⅳ報)

張香東 단국대학교 대학원 1981 學術論叢 Vol.5 No.-

On acidification of aflatoxin B_1, the lactone ring in reformed and can be extracted with chloroform (2nd report). After hydrogen peroxide treatment of the aflatoxin B_1 in alkaline medium can not be extracted by chloroform. This process dependent upon the opening of the lactone ring in pure crystall aflatoxin B_1 are effectively distroyed on pH=9 and pH=10, 100℃, and 0.125M―H_2O_2 The lactone ring of aflatoxin B_1 opens in the hydrogen peroxide by alkaline medium to yield the carboxyl and hydroxyl group. The separation of opened compound was carried out by elution chromatography. The identification of opened compound was determined to molecular weight by titration and Rast method, and it was confirmed by infrared spectroscopy.

Benzyl Nitrate로부터 Aldehyde 및 Acetate 轉換에 關한 硏究(第Ⅲ報)

張香東 서울産業大學校 1974 논문집 Vol.7 No.1

Benzyl nitrate was not only converted to benzaldehyde but also acetate in acetic acid containning a catalytic quantity of sulfuric acid. And it was, also,converted to aldehyde and acetate in toluene,tetrahydrofurane and dioxane. It colud be recovered unchanged after a solution in toluene was refluxed for 5 hr, One-third of the nitrate was converted to acetate, but no aldehyde was formed. The strong acid was an essential ingredient for aldehyde formation. The acctic acid solvent, on the other hand was not essential ingredient for aldehyde formation. But, it was an essential ingredient for acetate formation.

Aflatoxin B₁의 化學的 脫毒素化에 關한 硏究(第Ⅴ報)

張香東 서울産業大學校 1981 논문집 Vol.15 No.1

Oxidation of aflatoxin B₁by ozone (ozonized oxygen) at -78°C in chloroform gave the exo 2,3 -oxide (epoxide) on dluble bond of the terminal furane ring. The chloroform was removed in a stream of nitrogen and the residue was separated by elution column chromatography. The epoxide was identified by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and determined to molecular weight by Rast method. The result by elemental analysis of the resulting product was well agreed with calcd value and found value.