离子液体中聚乙二醇维生素E琥珀酸酯的合成

以离子液体为催化剂,由维生素E经两步酯化反应合成了聚乙二醇1000(PEG1000)维生素E琥珀酸酯。以离子液体1-(N',N'-二甲胺乙基)-3-甲基咪唑四氟硼酸盐为催化剂、1,2-二氯乙烷为助溶剂、维生素E与琥珀酸酐摩尔比为1:1.2,在80 ℃条件下反应4 h,维生素E琥珀酸酯(TAS)的产率为90%。以1-丙磺酸基-3-甲基咪唑硫酸氢盐/甲苯为反应体系,TAS与PEG1000摩尔比为1:2,在100 ℃下反应5 h,PEG1000维生素E琥珀酸酯(TPGS)收率为91%。     

抗氧化剂1790合成反应的研究

以6-叔丁基-3-氯甲基-2,4-二甲基苯酚和氰尿酸三钠盐为原料,在N,N-二甲基甲酰胺溶剂中合成1,3,5-三(4-叔丁基-3-羟基-2,6-二甲基苄基)-1,3,5-三嗪-2,4,6-(1H,3H,5H)-三酮(抗氧化剂1790),确定较佳的缩合工艺条件。考察了溶剂种类及用量、物料配比、反应温度及时间对反应收率的影响。实验结果表明:在N,N-二甲基甲酰胺溶剂中,反应温度为110℃,反应时间为2.5 h,n(6-叔丁基-3-氯甲基-2,4-二甲基苯酚)/n(氰尿酸三钠盐)=3.2∶1,产品收率为89%,纯度99%(HPLC面积归一化法)。产品结构经IR、MS和~1H-NMR表征。     

刮膜式分子蒸馏精制3-羟基丙腈

工厂通过精馏可获得纯度95% 的3-羟基丙腈(HPN)产品. 实验以95%浓度的HPN为原料, 应用刮膜式分子蒸馏装置进一步纯化, 考察了多种操作参数(温度、压力、进料速度、转速等)对目的产品中HPN纯度和馏出率的影响. 鉴于HPN在原料中为中间组分, 对于轻组分和重组分两种不同的目的产品, 分别得到了分子蒸馏精制HPN的最佳工艺条件. 还对于原料浓度为95%, 操作温度和压力在最佳范围时, 关联出了馏分中HPN纯度与操作温度和压力的函数关系式. 在最佳工艺条件下, 通过4级蒸馏, HPN的纯度可达99.5%以上. 实验和生产中, 精馏和萃取都还没有获得过99.5%的HPN纯度. 根据实验数据及分子蒸馏相关理论, 计算得出不同分离级数下HPN的蒸馏速率及分离效率. 计算结果显示, HPN的蒸馏速度和分离效率适宜于工业规模生产.     

天然维生素E分析的样品前处理方法研究新进展

维生素E是一种天然抗氧化剂,有重要的生理功能,其含量的分析检测至关重要。样品前处理在维生素E的分析检测过程中耗时最长,作用也最重要,并在一定程度上决定了样品中天然维生素E分析过程的效率和分析结果的信度。近年来,该领域的研究人员在样品前处理方面做了大量工作,开发出众多简捷、高效、可靠的维生素E提取方法。该文综述了皂化法、溶剂提取法、加压溶剂提取法、超临界流体萃取法和固相萃取法等近年发展起来的天然维生素E提取方法,介绍和评述了其应用及优缺点,并提出了发展方向。     

一种高分子紫外光吸收剂的合成研究

以2-(2-羟基-5-甲基苯基)苯并三唑、聚缩醛和哌嗪为原料,在乙二醇二甲醚溶剂中,经Mannich反应合成1,4-二[2-(2-羟基-5-甲基苯基)苯并三氮唑]哌嗪,确定了较佳缩合工艺条件。考察了物料配比、反应温度和时间对反应收率的影响,并经过正交实验,确定了反应的最佳工艺条件:在乙二醇二甲醚溶剂中,反应温度95℃,反应时间为24 h,n(2-(2-羟基-5-甲基苯基)苯并三唑)/n(HCHO)/n(哌嗪)=1.0∶1.5∶0.7,产品收率为82%,纯度98%(HPLC面积归一化法)。产品结构经IR、MS和1H-NMR表征。     

大环二萜类化合物的研究(Ⅳ)——Isosarcophytol—A前体化合物的合成

Isosarcophytol-A(1)是1982年首次从澳大利亚软珊瑚(Nephthea brassica)中分离鉴定的西松烷型(Cembrane)大环二萜类化合物,其结构为6,10,14-三甲基-3-异丙基-3E,5E,9E,13E-环十四碳四烯-1-醇,是Sarcophytol—A(2)的异构体,但有关1的生物活性试验和全合成研究尚未见报道.我们在前文报道了以低价钛诱导的分子内二羰基偶联为环化方法,完成了天然大环二萜类化合物Cembrene—C的全合成和Sarcophytol—A(2)苄醚衍生物(3)的合成.本文报道以天然法呢醇4为起始原料,经区域选择性氧化、羟醛缩合等六步反应,合成了1的前体化合物11.合成路线如下:     

类杂芪染料分子第一超极化率的溶剂效应研究

从实验上证明了反式-(2-N-甲基吡咯基)-(4-N-甲基吡啶基)杂芪碘(MPPSI),反式-(2-吡咯基)-(4-N-甲基吡啶基)杂芪碘(PPSI),反式-(2-呋喃基)-(4-N-甲基吡啶基)杂芪碘(FPSI)和反式-(2-噻吩基)-(4-N-甲基吡啶基)杂芪碘(TPSI)在15种溶剂中的分子第一超极化率(β~χ~χ~χ)与给电子取代基的富电子性间的线性关系,得到了β~χ~χ~χ值与溶剂极性间的线性相关性,从以上两个线性相关中得到了溶剂极性影响类杂芪分子给/吸电子取代基的给/吸电子能力的溶剂系数δ~A和δ~D,以及分子内电荷转移对溶剂极性的敏感因子η。     

6-叔丁基-3-氯甲基-2,4-二甲基苯酚的合成

以2,4-二甲基-6-叔丁基苯酚、多聚甲醛和三氯氧磷为原料,在四氯化碳溶剂中合成了6-叔丁基-3-氯甲基-2,4-二甲基苯酚并确定较佳的工艺条件,分别考察了物料配比、反应温度、反应时间和相转移催化剂用量对反应收率的影响。确定较佳工艺为:在四氯化碳溶剂中,反应温度为40℃,2,4-二甲基-6-叔丁基苯酚用量为60 g,多聚甲醛12 g,浓盐酸30 g,相转移催化剂4 g,三氯氧磷40 g。在上述条件下,6-叔丁基-3-氯甲基-2,4-二甲基苯酚的收率为95%,纯度>99%(HPLC面积归一化法),产品结构经IR、MS和~1H-NMR表征。     

一种新颖的构建(E)-3-芳氧基丙烯酸酯衍生物的方法

以炔酸酯和酚类化合物为原料,N,N-二甲基甲酰胺(DMF)为溶剂,Cu O/CH3ONa为促进体系,经过分子间的加成和自由基反应,成功地构建出了(E)-3-芳氧基丙烯酸酯衍生物.采用IR,1H NMR,13C NMR和元素分析对目标产物进行了表征.研究表明该方法具有原料便宜易得、后处理操作简单和产品纯度高等优点.     

1-烯丙基,3-甲基咪唑室温离子液体的合成及其对纤维素溶解性能的初步研究

随着不可再生资源 (如石油、天然气、煤矿和金属矿藏等 )的急剧耗竭 ,天然高分子的开发与利用日益引起世人的关注 .纤维素作为自然界中最丰富的天然高分子材料 ,其开发与利用一直备受关注[1] .但由于天然纤维素较高的结晶度和分子间和分子内存在大量的氢键 ,使其具有不熔化、在大多数溶剂中不溶解的特点 ,这成为纤维素在应用开发中的最大障碍 .开发有效的纤维素溶剂体系是解决这一难题的关键 .研究较多的纤维素溶剂主要有铜氨溶液、Ｎ 甲基吗啉 Ｎ 氧化物(ＮＭＭＯ)溶剂体系 ,氯化锂 二甲基乙酰胺 (ＬｉＣｌ ＤＭＡＣ)溶剂体系等[2 ] ,而这…     

An experimental approach to study the binding properties of vitamin E (alpha-tocopherol) during hairless mouse skin permeation.

An experimental approach to study the binding properties of vitamin E has been developed. Total vitamin E solubility in the skin was determined by a partition study, followed by in vitro skin permeation studies with whole skin and stripped skin. The amount of freely diffusable vitamin E in the diffusion process was determined from the permeation profiles of whole skin and stripped skin by employing a bi-layer model. The concentrations of vitamin E in the stratum corneum and viable dermis were determined separately. By subtracting this amount from the total concentration of vitamin E in the skin, as determined by the solubility study, the amount of bound vitamin E was determined. After skin permeation reached a steady state, the donor solution was removed and the permeation study continued (desorption study). During the entire period of the desorption experiment, the amount of vitamin E in the receptor solution hardly increased and remained constant. After the desorption experiment, vitamin E still remaining in the skin was determined by extracting with tissue solubilizer, SOLABLE, and is considered as the amount of vitamin E strongly bound in the skin. The concentrations of bound vitamin E determined by permeation and desorption studies coincided relatively well. To further investigate skin binding of vitamin E, a differential scanning calorimetry study was performed. Vitamin E-treated stratum corneum showed phase transitions at 76 and 85 degrees C, associated with lipid transitions. The thermal transitions associated with the lipid transition suggested interactions of vitamin E with lipid components of the skin. During skin permeation, vitamin E forms a very strong reservoir in the skin tissue and this amount of vitamin E, about 30%, exists as a bound-form with the lipid components of the stratum corneum.     

An electrophoretic study of vitamin E status and expression of heat shock proteins in alveolar type II and liver cells

Vitamin E is the most important lipophilic antioxidant. Oxidative injuries are prevented or minimized by vitamin E supplementation. Various physiological and pathological situations are accompanied by vitamin E deficiency. However, it is not clear whether alimentary vitamin E deficiency in itself constitutes oxidant stress that induces appropriate responses, which, in turn, can be avoided by adequate vitamin E supplies, or whether the remaining cellular antioxidants compensate a temporary vitamin E deficiency. We studied effects of the dietary vitamin E status on cellular vitamin E levels and on the expression of heat shock proteins (HSPs) in alveolar type II cells and liver. The expression of HSPs, representing an early and very sensitive marker of cellular stress, was compared with the activity of antioxidative enzymes. Vitamin E depletion caused a substantial increase in HSP32 in alveolar type II cells, whereas in liver there was a marked increase in HSP70. The activity of the antioxidant enzymes, however, did not change significantly. A reversal of HSP expression to almost normal levels was seen after vitamin E resupplementation. These results indicate that, under normal conditions, a suboptimal supply of vitamin E to rats exposes the alveolar type II cells and the liver to reversible cellular stress.     

高硒情况下维生素E对幼龄大鼠抗氧化作用的研究

研究了高Se或高维生系E下,幼龄大鼠体内抗氧化活性的变化以及高Se下,维生素E对其体内抗氧化水平的影响。将三月龄Wistar大鼠32只随机分成4组：正常饲料组、高Se高维生素E饲料组、高Se饲料组和高维生素E饲料组。饲至十周末,处死大鼠,按试剂盒要求分别取其血液、心、肝、肾制成标本测SOD、CAT活性及MDA、GSH含量。结果表明,高Se或高维生素E下饲养下的大鼠与对照组比较,血液中SOD活性明显下降;维生素E能明显抑制高Se大鼠血液中SOD活性的下降。结论：单独高Se或高维生素E会降低幼龄大鼠的抗氧化活性,而维生素E能明显提高高Se下幼龄大鼠体内抗氧化活性。     

Design,synthesis and cytotoxic activity of vitamin E bearing selenium compounds against human breast cancer cell line (MCF-7)

A new series of vitamin E/selenated pyridine, vitamin E/selenated pyridazine, vitamin E/selenated coumarine and vitamin E/selenated nicotine moieties were synthesized and their cytotoxic activity is investigated using the human breast cancer cell line. The newly synthesized compounds were characterized using spectroscopic tools (IR, ¹H NMR, ¹³C NMR, and mass spectroscopy) as well as microanalysis. Our study reveals that compound vitamin E/selenated nicotine moiety has the highest cytotoxic effect than the other synthesized compounds.     

高硒情况下维生素E对老龄大鼠血清中抗氧化作用的影响

研究了高Se或高维生素E下，老龄大鼠体内抗氧化活性的变化以及高Se下维生素E对其体内抗氧化水平的影响。将十二月龄Wistar大鼠32只随机分成4组：（1）正常饲料组；（2）高Se饲料组；（3）高维生素E饲料组；（4）高Se高维生素E饲料组。饲至十周末，处死大鼠，按试剂盒要求取其血液制成血清测GSH－Px,SOD活性，MDA含量。结果表明，高Se或高维生素E下饲养下的大鼠与对照组比较，血清中GSH－Px活性升高（P＜0．05）。SOD活性未见改变，MDA含量分别减少50％和56％，有显著差异（P＜0．01）；维生素E与高Se合用与高Se组比较能进一步同GSH－Px,SOD活性（P＜0．01）。结论：高Se会升高老龄大鼠的抗氧化活性，而与维生素E合用更加升高老龄大鼠血液中抗氧化活性。     

高硒及高硒高维生素E合用对十二月龄大鼠血清MDA和ALT的影响

给动物喂食高Se、高vitaminE、高Se高vitaminE合用饲料 ,探讨单独及合用高Se、高vitaminE对十二月龄动物血清中MDA和ALT的影响。结果显示 ,与对照组比较 ,单独及合用高Se、高vitaminE均可显著降低血清中MDA的含量 (P <0 0 1 ) ,高vitaminE尚能使血清中ALT水平升高 (P <0 0 5 ) ,而高Se高vitaminE合用则可纠正高vitaminE引起的血清中ALT水平的升高     

镁离子、维生素E抗氧化作用的研究

为研究镁离子、维生素E体内外抗氧作用,探讨镁离子抗氧化作用的机制,将3月龄昆明种小鼠70只随机分7组,设正常对照组、氧化对照组、63、42、21mmol／L镁保护组,镁和维生素E保护组,维生素E保护组,饲养10d,腹腔注射0．15％CCl4致小鼠肝损伤,观察镁离子、维生素E对小鼠肝匀浆中MDA、SOD、GSH含量的影响;在肝匀浆中加入FeSO4和H2O2诱导自由基的生成,观察镁离子、维生素E的抗氧化作用。结果表明,镁离子、维生素E能显著降低肝匀浆中脂质过氧化物MDA的含量,对SOD、GSH无明显影响。提示镁离子、维生素E能抑制自由基的生成,促进自由基清除作用。     

A CIDEP and fluorescence study of the oxidation of vitamin E: The vitamin E radical cation

The photochemical and thermal oxidations of vitamin E in trifluoroacetic acid were investigated by the combination of electron spin resonance, chemically induced dynamic electron polarization, and fluorescence techniques. Two independent thermal pathways led to the formation of the vitamin E radical cation in which one of the paths involved the intermediate neutral semiquinone radical. Photo-oxidation, however, did not involve the neutral radicals. The fluorescence spectra of both the neutral and the charged forms of the vitamin E radicals are reported here for the first time. Some model charge transfer reactions involving the vitamin E radical cation were reported.     

Rapid dissolution of vitamin E by using sodium N-lauroylsarcosinate ionic surfactant

Vitamin E is widely used in pharmaceutical, food and cosmetic preparations. This paper discusses methods of preparing a vitamin E emulsion by using sodium N-lauroylsarcosinate (SNLS) ionic surfactant. The amount of vitamin E dissolved in water was analyzed by turbidity and UV absorption measurements. The emulsion droplet size was determined by laser light scattering. Microemulsions with small particle size and high resistance to oxidation in air can be obtained by solubilizing vitamin E in SNLS solution. The dissolution is rapid and the surfactant solution has high solubilization power. At 0.7% surfactant concentration, the saturation value is 1 g vitamin E per gram of surfactant. The micellar dissociation concentration (MDC) of the surfactant can be estimated from a vitamin saturation—surfactant concentration curve. Dissolution mechanisms at different surfactant concentrations are interpreted by use of the MDC and CMC (critical micellar concentration) concepts.     

Are Vitamin E Supplementation Beneficial for Female Gynaecology Health and Diseases?

Vitamin E is known as an essential vitamin, and many studies had demonstrated the importance of vitamin E throughout the reproductive process, such as miscarriage, premature birth, preeclampsia, and intrauterine growth restriction, which could be caused by a lack of vitamin E during pregnancy. Its potent antioxidant properties can counteract the oxidative stress induced by oxygen free radicals and imbalance of oxidative-antioxidant levels, hence it may play a role in maintaining the normal function of the female reproductive system. Despite the fact that vitamin E is acknowledged as the substance needed for reproduction, its beneficial effects on female fertility, gynaecological health, and diseases are still poorly understood and lacking. Therefore, the goal of this paper is to provide a summary of the known roles of vitamin E supplementation in women for gynaecological health and reproductive-related diseases, as well as its future perspective.