An hypothesis for the mechanism of the heme catalyzed lipid oxidation in animal tissues

The catalytic activity of the heme compounds on lipid oxidation in muscle tissues has been reviewed. Evidence from experiments found in the literature, and unpublished studies in this laboratory on meats and fishery products, lead to the conclusion that the ferric heme compounds initiate lipid oxidation, while the ferrous heme compounds are inactive in the absence of preformed peroxides. The latter are decomposed by both types of heme compounds, but by a different mechanism. A comprehensive mechanism of the different catalytic activities of the various heme compounds has been presented, based on both experimental evidence and theoretical considerations.     

Effect of heme compounds on lipid oxidation

By polarographic oxygen analyzer, the rate of oxidation of linoleate solutions was catalyzed by low concentrations of heme and heme-proteins and inhibited by higher concentrations. High concentrations of these substances also inhibited lipoxygenase catalysis of linoleate oxidation. Manganese and cobalt salts inhibited heme-catalyzed linoleate oxidation. These combined effects may reflect the oxidative synthesis of antioxidants from heme compounds. One of 28 papers presented at the Symposium, “Metal-Catalyzed Lipid Oxidation,” ISF-AOCS World Congress, Chicago, September 1970.     

维生素E的稳定性研究

在氮气保护下,研究了不同温度下维生素E的稳定性,比较了维生素E在不同溶剂（甲醇、乙醇、正已烷和油酸甲酯）中的稳定性,并研究了Fe3＋、Ca2＋、N-等金属离子对维生素E稳定性的影响。研究表明维生素E在无水甲醇溶剂中相对更稳定;金属离子Na＋严重破坏维生素E稳定性。     

Acceleration and inhibition of lipid oxidation by heme compounds

The acceleration and inhibition of unsaturated fatty acid oxidation by heme compounds was followed in model systems with an oxygen analyzer. The linoleate to heme molar ratios for maximum catalysis were 100 for hemin and catalase, 250 for metmyoglobin, 400 for cytochrome c and 500 for methemoglobin. With heme concentrations of 2 to 4 times the optimum catalytic amount, no oxidation occurred. Rapid heme destruction was observed with catalyzing ratios of lipid to heme, but with inhibitory ratios a stable red compound formed, believed to be a lipid hydroperoxide derivative of the heme. The ratios of lipid to metmyoglobin for maximum acceleration varied with the pH. Linolenate was much less sensitive to heme catalysis than linoleate. Colorless products of heme degradation had a marked antioxidant effect. A possible mechanism for the antioxidant effect of hemes is advanced, based on the formation of stable heme peroxide complexes or stable heme radicals, or both, during the early stages of oxidation. Prooxidant activity is believed to occur only when the peroxide to heme ratio is so high that the oxidation of the hemes goes beyond the initial stages.     

天然维生素E的提取

对经酯化、脱甾醇处理后的油脂脱臭物采用简单蒸馏方法提取维生素E。结果表明维生素E的收率在87%以上,产品含量达51%以上。     

维生素E醋酸酯在牙膏的应用

本文介绍了维生素E醋酸酯，论述了维生素E醋酸酯对口腔疾病的作用，并对维生素E醋酸酯在牙膏中的运用工艺技术开发提出见解，在增加牙膏功效及维生素E运用工艺技术等方面很有借鉴价值。     

天然维生素E生产现状与应用前景

介绍了国内外天然VE的市场需求、应用、发展趋势以及以植物油、油渣、脱臭物为原料制备天然VE的工艺,并对我国天然VE工业发展提出了建议.     

Vitamin E Supplementation of Smokers and Non-Smokers

Twenty male smokers and 20 non-smokers took either vitamin E capsules (1000 IU/day) or placebo for 14 days. Erythrocytes from smokers showed a marked tendency to peroxidise in vitro compared with non-smokers, an effect which was abolished by vitamin E supplementation. The increased erythrocyte peroxidation may reflect a lipid hydroperoxide-induced decrease in glucose-6-phosphate dehydrogenase activity. Evidence that smokers incurred a sustained oxidant stress also included increased plasma conjugated dienes, decreased plasma vitamin C and an increase in erythrocyte glutathione. Plasma cholesterol, vitamin E and conjugated dienes increased with age in all groups. Results suggest that smokers are under a sustained oxidant stress, some indices of which can be partially ameliored by vitamin E supplementation.     

Vitamin E Conditionally Inhibits Atherosclerosis in ApoE Knockout Mice by Anti‐oxidation and Regulation of Vasculature Gene Expressions

Lipid deposition in artery walls is implied in the pathogenesis of atherosclerosis and imbalance between uptake and efflux of cholesterol favors the deposition. We investigated the effect of vitamin E with the same dose and duration on the different stages of atherosclerosis in Apolipoprotein E knockout (ApoE KO) mice and explored the potential mechanisms. The results showed that the ApoE KO mouse spontaneously develops atherosclerosis in an age‐dependent manner from 14 to 46 weeks on the regular chow. Vitamin E (100 mg/kg) supplementation to ApoE KO mice at 6, 14, and 22 weeks for 8 weeks significantly reduced the atherosclerotic lesion area by 41, 29 and 19 % respectively compared to the age‐matched control mice; however had no significant effect on the lesion when given at 30 and 38 weeks. In addition, vitamin E supplemented at the ages from 6 to 30 weeks decreased the contents of serum oxLDL and TBARS without affecting the TC and TAG contents in serum and liver. Furthermore, vitamin E supplemented at 6, 14 and 22 weeks down‐regulated vasculature mRNA expressions of scavenger receptor CD36 and up‐regulated mRNA expressions of PPARγ, LXRα and ABCA1 which are involved in reverse cholesterol transportation; however had no significant effects on these genes when given at 30 and 38 weeks. In conclusion, vitamin E with same dose and duration inhibits the early but not advanced atherosclerotic lesion in ApoE KO mice by anti‐oxidation and regulation of mRNA expression of genes involved in cholesterol uptake and efflux, which favors the improvement of atherosclerosis.     

微生物维生素E产业化开发进展

维生素E是一种脂溶性抗氧化剂,仅在光合细菌和高等植物中合成,具有重要的生理学功能.纤细裸藻能有效积聚α-生育酚.本文综述了通过代谢和基因工程、培养系统和反应器等方面的研究来有效生产生育酚的进展情况,旨在促使工业化生产维生素E成为可能.     

维生素E烟酸酯的合成工艺概况

途述了以烟酸、烟酰氯、烟酸酯为原料或以异植醇为原料合成维生素E烟酸酯的工艺路线，并评述了各工艺的优缺点，认为Michiko工艺路线工艺简单、收率高、原料价格便宜、具有工业竞争力。     

天然维生素E微乳制剂的流变性研究

药用物料的流变特性,是反映药品物料品质和物理特性的重要参数。文章综合了目前国内外在微乳黏度与剪切率、剪切应力与剪切率、温度与黏度方面的研究成果和研究现状,并结合具体对天然维生素E微乳制剂的流变性研究加以说明。对目前流变学研究存在的问题,指出未来微乳流变性研究,应以流变成因为核心等方面着手优化更新研究和探讨。     

天然维生素E生产现状与应用前景

介绍了国内外天然VE的市场需求，应用、发展趋势以及以植物油、油渣、脱臭物为原料制备天然VE的工艺，并对我国天然VE工业发展提出了建议。     

维生素E的电化学研究进展

电化学研究表明α-,β-,γ-,δ-四种生育酚在不同的酸碱条件下发生一系列质子-和电子-转移过程,生成酚氧正离子、正离子自由基和二价正离子。这些正离子比其他酚类化合物生成的正离子稳定,而由α-生育酚氧化生成的酚氧正离子尤其稳定,能在有机溶剂中存活几个小时。     

我国维生素E市场前景分析

维生素E目前全球需求平稳增长,年均增长率为7％～10％。针对我国维生素E生产现状进行分析,指出国内市场急需拓展,市场前景广阔。     

维生素E的合成与分析研究现状

主要介绍了天然维生素E的制备提取,人工合成维生素的合成机理及工业上的合成现状。并对维生素E化学合成的进展进行了阐述。并对维生素E的分析检测进行了简单的论述,本文以市场的角度分析了我国天然维生素E存在的不足,并提出了将来合成工作与分析工作的重点,提高天然维生素E制剂的质量以进入欧美发达国家市场。     

维生素E及其衍生物合成进展

综述了维生素E及其衍生物的合成进展.     

分子蒸馏技术浓缩合成维生素E

对分子蒸馏浓缩合成维生素E进行了研究,在刮膜器转速200 r/min、操作压力0.1 Pa、蒸馏温度158 ℃、进料速率110 mL/h下,经分子蒸馏处理后的合成维生素E纯度可达到98%以上;同时研究了主要的操作参数对产品纯度的影响;另外,根据实验数据进行拟合,得到了在一定范围内准确度较高的馏出物轻组分浓度预测式。     

天然维生素E的提取工艺与检测技术

简要介绍了维生素E的分布和生理作用,重点综述了天然维生素E提取工艺及维生素E的检测技术。     

维生素C和E对Klebsiella pneumoniae合成1,3-丙二醇的调控

通过外源添加还原剂的方式调控细胞内NADH/NAD再生系统的状态,研究了40~150 mg/L VC及20~100 mg/L VE对Klebsiella penumoniae合成1,3-丙二醇的影响,发现外源添加150 mg/L VC或30 mg/L VE均可使1,3-PD合成浓度提高20%~30%;但同时也提高了某些副产物的合成浓度,对代谢流分布的调控作用不明显;1,3-丙二醇得率稍有提高但不显著. 提高1,3-PD得率宜从代谢节点(丙酮酸)通量调节方面考虑.