【作者】 于丽娜；

【导师】 汪东风；

【作者基本信息】 中国海洋大学 ， 水产品加工及贮藏工程， 2005， 硕士

【摘要】 稀土元素具有很好的水解RNA和DNA的活性,尤其铈离子水解活性显著高于其它稀土元素。并且水解只作用于RNA和DNA的磷酸酯键,而不会产生其它的氧化副产物。但是在生理pH值下,铈离子会形成很稳定的铈离子氢氧化物的凝胶状沉淀,降低了铈离子的溶解性,给它的应用带来了很大的局限。这就需要找到一种合适的配体将铈离子与配体络和形成配合物,提高它的应用范围。 由于琼脂糖是D—半乳糖和3,6—脱水—L—半乳糖相间结合的链状多糖,由其制成的珠状颗粒是一种理想的层析介质。因此,本文用琼脂糖作为配体,与铈离子在乳化剂吐温—80、司班—85和环己烷的作用下,通过二次乳化作用合成了琼脂糖—铈配合物微粒(PACC)。并通过显微摄影、紫外、红外、荧光光谱分析对PACC作了初步的表征。同时对PACC的使用条件,如pH值、温度,离心、超声,丙酮、乙酸乙酯,以及PACC的储藏期作了初步的研究。 对于PACC的活性,本文主要研究了PACC对磷酸酯键和肽键的水解活性。发现PACC对对硝基苯磷酸二钠(PNPP2Na,磷酸酯键的模型化合物)有很好的水解活性。其水解的表观速率常数为PNPP2Na自发水解的120倍。此外,PACC对含有磷酸酯键的一大类有机物质—有机磷农药也有降解效果。其中,甲胺磷、氧化乐果和毒死蜱的降解率分别达到:32.39%,27.12%和46.62%。并且,PACC对茶叶浸提液和豆芽汁中残留的有机磷农药也有降解效果。茶叶浸提液中残留的毒死蜱的降解率达到59.76%,豆芽汁中残留的毒死蜱和甲胺磷的降解率分别达到38.28%和35.45%。另外,PACC对肽键也有较强的水解作用。PACC在搅拌反应器中应用对BSA的水解率可达到4.07%。PACC作柱填补料时,过柱后氨基酸含量为过柱前的2.3倍。当茶汤经过PACC柱处理后,其氨基酸含量为处理前的1.87倍。更多还原

【Abstract】 Rare earth elements (REE) can hydrolyze RNA and DNA. Especially, the hydrolysis activity of Ce(Ⅳ) is more than that of other REE, and only phosphoester bonds of DNA or RNA can be hydrolyzed by Ce(Ⅳ). Furthermore, some oxidation byproducts can’t be produced during the hydrolysis reaction. Whereas, a great deal of steady gelatinous Ce(Ⅳ)-OH deposit will be formed at physiological pH so as to reduce the solvency of Ce(Ⅳ). Therefore, one suitable ligand which can react with Ce(Ⅳ) must be found in order to broaden its purpose.Agarose, which is a kind of catenarian amylose, is consisted of D-galactose and 3,6-dehydration-L-galactose. And agarose particles are a sort of ideal chromatography medium. Therefore, particles of agarose- Ce(Ⅳ) complexes (PACC) are obtained by twice emulsification by making use of agarose as ligand and tween-80, span-85 and cyclohexane as emulsion. PACC are primarily described by micrography、 UV spectrum、 IR spectrum and fluorescence spectrum. The using environment of the PACC such as pH、 temperature、acetone、 ethlylacetate、 centrifugal effect and ultrasonic effect are discussed in this paper.At the same time, hydrolysis activities of PACC for phosphoester and peptide bonds are mainly studied. The results show that PNPP2Na, which is regarded as the model compound of phosphoester bonds, can be hydrolyzed by PACC. Furthermore, the hydrolysis activities of PACC for organophosphorus pesticides which have phosphoester bonds are also discussed. The degraded rates of methamidophos、omethoate and chlorpyrifos are 32.39%, 27.12% and 46.62% respectively. And PACC candegrade organophosphorus pesticide residues consisting in the tea extract and sprout juice. The degraded rate of chlorpyrifos in the tea extract is 59.76%. And the degraded rates of chlorpyrifos and methamidophos in sprout juice are 38.28% and 35.45% respectively.The hydrolysis activity of PACC for bovine serum albumin (BSA), which has peptide bonds, is good. The degraded rate of BSA is 4.07% by using PACC in stirring reactor. The content of amino acid in BSA after reaction is 2.3 times more than that of amino acid in BSA before reaction when PACC add to glass chromatography column. The content of amino acid in tea extract is 1.87 times more than that of amino acid in tea fumet when tea passes through PACC column.It is important to prepare particles of agarose- Ce (IV ) complexes ( PACC) in this paper. And theoretic significance and actual value is great. The results show that PACC can hydrolyze phosphoester and peptide bonds. Therefore, a new investigative aspect of mimic of phosphoester enzyme and mimic of protein enzyme is obtained. A new method of degrading organophosphorous pesticides in products from farm produce will be found if PACC can hydrolyze organophosphorous pesticides in fruit and vegetable juice. At the same time, a new kind of technology of hydrolyzing protein in beverage industry is gained.更多还原