硒酵母培养过程中亚硒酸钠添加量对硒酵母中硒含量分布的影响

采用在培养基中添加亚硒酸钠的方法，培养出了五种不同含硒量的硒酵母，并对硒酵母中总硒、无机硒、有机硒、硒蛋氨酸和硒胱氨酸的含量进行了测定，从所测数据中可以得出酵母同化无机硒为有机硒的基本规律，确定了在硒酵母的培养过程中最适宜的亚硒酸钠添加量为１５～２０μｇ／ｍｌ。     

合成硒脲及2—氨基硒唑的新方法

Ｓ－甲基假硫脲与硒氢化钠在回流的无水乙醇中反应得硒脲，产率较高。方法中不使用毒性较大的硒化氢气体。将所合成的硒脲与α－卤代酮反应，得２－氨基硒唑卤化氢，用水重结晶。产率高，方法简便。     

积极开发富硒保健品

简介了硒对人体的作用，建议开发富硒天然食品，如硒蛋、富硒茶、富硒蛋白制剂等，以及开发硒化卡拉胶、硒代蛋氨酸及肌醇硒酸酯钠等有机硒化物。     

硒的生物转化和补硒形式的研究

1前言硒是1817年瑞典化学家Berzelus首先发现并鉴定的介于金属元素和非金属元素之间的一种稀有分散元素。在地壳中的相对丰度0．05mg/kg－0．09mg/kg，分布不均匀，呈明显的地带性分布。世界上有40多个国家的土壤缺硒。我国存在一条由东北向西南延伸的以棕褐土体系为中心的低硒带[1]，黑龙江省属严重缺硒地区，土壤平均全硒含量为0、190mg/kg硒与人畜健康密切相关。1973年，联合国卫生组织宣布硒是动物生命中的必需微量元素。硒在农业生产、人畜健康和环境保护中的重要性已越来越受到关注。2硒与健康的关系研究表明，硒过量或缺乏均会导致…     

硒及富硒腐植酸生物液体肥对主要粮食作物应用效果的研究

详细介绍了富硒腐植酸生物液体肥在提高土壤硒含量，以及在主要粮食作物上的应用，并以详实的数据说明富硒腐植酸生物液体肥的增产效果。是生产绿色食品必备肥料之一。     

硒-呵护生命的“女神”

上个世纪50年代，人类已经发现了20种氨基酸，科学家在新发现了一种非常重要的含硒的氨基酸-硒半胱氨酸后，将它称作”第21种氨基酸”。那么，这种新发现的”第21种氨基酸”，对人体有哪些作用呢?人体中，硒的作用是广谱的，它是多种酶的活性中心，其在人体的生命活动中起到抵御疾病、防止衰老、增强机体免疫功能，从而达到平衡机体的作用。硒是一种强抗氧化剂，它的抗氧化能力比作用强大的维生素E还要大50-500倍。可见它对人体的重要性。     

二苯二硒的改进合成方法

在乙醚和９５％乙醇溶剂中，以过碳酸钠为助氧化剂，通入空气，将苯硒酚制成二苯二硒，收率可达７６．５％（以溴苯计）。     

硒在动物饲养中的应用及测定方法

我国是一个缺硒大国,动物和人体的缺硒情况正在加剧。在饲料中添加硒补充剂,增加动物体中硒浓度,从而增加人体硒浓度。饲料通常用各种硒源补充,但有机形式比无机形式(亚硒酸盐、硒酸盐)的生物有效性更高,且毒性更少。这篇综述介绍了硒对人体和动物的重要性,硒测定的方法及其在动物饲养中的应用。     

噻吩基和呋喃基—1,2,3—硒二唑的制备

合成了未见文献报道的４种噻吩基和呋喃基－１，２，３－硒二唑衍生物。对取代缩氨脲关环生成相应硒二唑，提出了合理的反应机理。     

硒及其有机衍生物的性质与合成

硒及其有机衍生物的性质与合成李许珍ＰＲＯＰＥＲＴＩＥＳＡＮＤＳＹＮＴＨＥＳＩＳＯＦＳＥＡＮＤＩＴＳＯＲＧＡＮＩＣＤＥＲＩＶＡＴＩＶＥＳ１引言１８１８年瑞典化学家贝采里乌斯仔细研究了制造硫酸过程中沉积在铅室的粉末，发现一种可燃性单质，命名为硒，硒在生物...     

Crystalline Sodium Selenocarboxylates – synthesis and characterization

A series of sodium selenocarboxylates 2 were isolated from the reaction of diacyl selenides with sodium ethanolate and characterized. A convenient preparation of the sodium salts 2 by the direct reaction of acyl chlorides with sodium selenide was also established. The salts are colourless to slightly pale yellow crystals and labile towards moisture. They readily react with alkyl iodides at room temperature to give the corresponding Se-alkyl esters 3 .     

二烷基二苯醚磺酸盐驱油剂的研制

以二苯醚和系列α-烯烃为原料合成出二烷基二苯醚,经氯磺酸磺化和NaOH溶液中和,制得系列二烷基二苯醚单磺酸钠(MAMS)阴离子表面活性剂。测定了表面活性剂溶液与烷烃之间在不同条件下的界面张力,并讨论了盐度、活性剂浓度和烷烃链长对表面张力的影响。     

Anionic phosphate surfactants

Conclusions A study of the sodium monoalkyl phosphates and sodium dialkyl phosphates has shown that the dialkyl esters, in general, possess markedly superior surfactant and detergent properties compared to the monoalkyl esters. This is true whether we are comparing equivalent mol wt mono- and diesters or when comparing those made from the same alcohols. The branched chain didecyl ester, in addition to giving aqueous solutions of exceptionally low surface tensions and possessing a very low critical micelle concentration, also performs exceptionally well in built detergents. In fact, our data indicate that its performance characteristics are considerably better than commercial surfactants used today in these types of products.     

Fullerene lipids: Synthesis of dialkyl 1,2-[6,6]-methano-[60]-fullerene dicarboxylate derivatives

Reaction of C₆₀ fullerene with dialkyl bromomalonate (where the alkyl groups consist of short-, medium-, and long-saturated chains or unsaturated long chains) in the presence of sodium hydride gives [6,6]-bridged mono-adducts of methanofullerene. The spectroscopic properties of such fullerenoid lipids are reported.     

Sodium dialkyl phosphates: Surfactant properties and use in heavy duty detergents

A study of the physical and surface active properties of the sodium salts of dialkyl phosphates has been made. These compounds have been evaluated for use as surfactants in built detergents and their performance has been compared with commercial surfactants. The dialkyl hydrogen phosphates contained from 16–26 carbon atoms per molecule and were prepared from both straight chain alcohols and commercially available branched chain alcohols. In general, the surface active properties of the branched chain compounds are better than their corresponding straight chain compounds. Good detergency performance is obtained when the number of carbon atoms per molecule is between 17 and 23. Optimum performance is obtained with the symmetrical didecyl hydrogen phosphate salts made from commercial decyl alcohol produced by the oxo-process.     

α-Substituierte Phosphonate. 39. Methandiphosphonsäureester durch UV-induzierte Michaelis-Becker-Reaktion

α-Substituted Phosphonates. 39. Methane-diphosphonic Esters by U.V.-Induced Michaelis-Becker-Reaction Dibromomethane resp. chlorbromomethane reacts with sodium dialkyl phosphite in heptane-/liq.NH₃ or in liq. NH₃ by u.v. irradiation at low temperatures to give in good yields methane diphosphonic acid tetraalkylesters 1 . In the same manner with sodium diethyl thionophosphite the corresponding methane-bis-thiophosphonic acid tetraethylester 4 is obtained.     

Regulation of molecular weight of styrene—butadiene rubber. I. Choice of regulator from the homologous series of xanthogen disulfides

The regulating efficiency of 14 dialkyl xanthogen disulfides in emulsion copolymerization of butadiene with styrene at +5°C. with the use of a diisopropylbenzene hydroperoxide–complexed ferrous iron–sodium formaldehyde sulfoxylate redox system in the presence of sodium soap of disproportionated rosin as an emulsifier, was evaluated. The apparent chain transfer constants of n-alkyl and isoalkyl derivatives decreased logarithmically with increasing length of the alkyl group, which seems to be related to the analogous dependency of their solubilities in water. The dialkyl xanthogen disulfides, especially the lower homologs, acted as retarders of polymerization. The retardation did not affect their regulation efficiency. On the basis of values of the apparent chain transfer constants it is possible to predict the molecular weight of polymers, except for the region where the regulation is poor and where the deteriorative influence of termination and crosslinking reactions takes place. The diisopropyl xanthogen disulfide has been selected as the most convenient of the compounds studied for molecular weight regulation of emulsion copolymerization of butadiene with styrene in the system mentioned.     

In Vitro Cytotoxicity of Trastuzumab (Tz) and Se-Trastuzumab (Se-Tz) against the Her/2 Breast Cancer Cell Lines JIMT-1 and BT-474

Her/2+ breast cancer accounts for ~25% mortality in women and overexpression of Her/2 leads to cell growth and tumor progression. Trastuzumab (Tz) with Taxane is the preferred treatment for Her/2+ patients. However, Tz responsive patients often develop resistance to Tz treatment. Herein, redox selenides (RSe-) were covalently linked to Tz using a selenium (Se)-modified Bolton–Hunter Reagent forming Seleno-Trastuzumab (Se-Tz; ~25 µgSe/mg). Se-Tz was compared to Tz and sodium selenite to assess the viability of JIMT-1 and BT-474 cells. Comparative cell viability was examined by microscopy and assessed by fluorometric/enzymatic assays. Se-Tz and selenite redox cycle producing superoxide (O₂^•−) are more cytotoxic to Tz resistant JIMT-1 and Tz sensitive BT-474 cells than Tz. The results of conjugating redox selenides to Tz suggest a wider application of this technology to other antibodies and targeting molecules.     

Electrophilic addition of thioselenophosphinic acids to vinyl sulfides and selenides

The thioselenophosphinic acids, R₂P(Se)SH (R?=?Ph, Cy, aralkyl), prepared by acidification of the sodium salts or generated in situ by reaction of secondary phosphine sulfides with elemental selenium, add easily to diverse vinyl sulfides and vinyl selenides in a Markovnikov manner to give the corresponding S- and Se-esters in a ～60:40 molar ratio (83–96% total yield).     

Green synthesis of tertiary alkylselanylphosphine chalcogenides via catalyst- and solvent-free addition of secondary phosphine chalcogenides to vinyl selenides

Secondary phosphine sulfides and phosphine selenides react with vinyl selenides under mild conditions (80–82°C, without catalyst and solvent) to form regioselectively functionalized anti-Markovnikov adducts in high yield.