离子色谱法测定饲料中的甜菜碱

建立了离子色谱法测定饲料中甜菜碱的方法。向饲料样品中加水并超声提取,加入三氯甲烷剧烈振摇,离心取上清液,以离子色谱非抑制电导检测器测定其中的甜菜碱。结果表明,甜菜碱的质量浓度在50~1000 mg/L的范围内与电导率线性关系良好,相关系数为0.9995。甜菜碱的定量限为41 mg/kg,优于国家标准的定量限(200mg/kg),加标回收率为102.4%,重现性的相对标准偏差为1.19%(n=5)。该法可应用于饲料行业的例行检测。     

毛细管电泳法测定猪体组织中甜菜碱含量

建立了毛细管电泳法快速测定猪体组织中甜菜碱含量的方法。甜菜碱首先转化为苯甲酰甲基酯后直接上样测定。pH为 3 .0的磷酸缓冲溶液使甜菜碱酯化物和甜菜碱结构类似物酯化物之间以及酯化物和酯化剂之间都能很好地分离 ,这也省去了反应混合液的前处理。该法标准曲线的线性范围为 4～ 6 0 0mg L ,相关系数r为 0 .9999,最低检测限为 1mg L ,相对标准偏差为 2 .2 %～ 4.7% ,标准加入回收率为 95 9%～ 98.4%     

毛细管电泳法测定猪体组织中甜中甜菜碱含量

建立了毛细管电泳法快速测定猪体组织中甜菜碱含量的方法。甜菜碱首先转化为苯甲酰甲基酯后直接上样测定。pH为3.0的磷酸缓冲溶液使甜菜碱酯化物和甜菜碱结构类似物酯化物之间以及酯化物和酯化剂之间都能很好地分离,这也省去了反应混合液的前处理。该法标准曲线的线性范围为4-600mg/L,相关系数r为0.9999,最低检测限为1mg/L,相对标准偏差为2.2%-4.7%,标准加入回收率为95.9%-98.4%。     

化学复合驱用甜菜碱型表面活性剂的研究进展

简述了化学复合驱用甜菜碱型表面活性剂的研究现状.首先总结了羧基甜菜碱和磺基甜菜碱型表面活性剂的合成工艺进展;其次介绍了化学复合驱用甜菜碱型表面活性剂各方面的特性,主要包括其界面性质、耐温抗盐性以及与其它类型表面活性剂的复配性能;最后探讨了甜菜碱在油田上应用的可行性.     

Gemini型甜菜碱表面活性剂合成进展

Gemini型甜菜碱结合了甜菜碱和Gemini型表面活性剂的优点,可以在较低浓度下达到超低油水界面张力、配伍性好、耐温耐盐性好、Krafft点以及吸附量低,被广泛应用于日用化学、化学化工、纳米材料、生物技术和石油开采等领域。本文基于间隔基的类型介绍了近年来Gemini型甜菜碱表面活性剂方面的最新研究进展。重点阐述了对称胺型、三嗪环型、二卤代物型Gemini甜菜碱的合成方法,并从原料成本、产率、反应周期以及产物的性能等方面对合成方法进行了分析和比较。最后对Gemini型甜菜碱表面活性剂的发展进行了展望。     

水解可控功能切换型聚合刷的构筑及表面性能

采用表面受限光接枝技术在玻璃表面构筑末端酯键可水解的羧酸甜菜碱酯阳离子聚合物刷(PCBMA-1C2),通过调节氨水浓度控制羧酸甜菜碱酯末端酯键的水解程度,实现表面聚合物刷中季铵阳离子和羧酸甜菜碱两性离子基团分配比例的改变.通过X射线光电子能谱(XPS)和接触角测试表征了改性表面的化学结构和亲/疏水性能,通过蛋白质吸附和血小板黏附实验研究了玻璃表面改性前后及水解前后电荷性质对生物分子相互作用的影响.结果发现,当氨水浓度为0.1,0.2,0.3和0.4 mol/L时,聚合物刷PCBMA-1C2改性表面羧酸甜菜碱酯末端酯键的水解率分别为6%,43%,56%和~100%,随着水解程度的增大,改性表面牛血清白蛋白(BSA)的吸附量依次降低了3%,76%,93%,96%,纤维蛋白原(Fg)吸附量则依次降低了11%,45%,90%和96%;当水解率50%时,改性表面表现出优异的抗蛋白质吸附和血小板黏附性能.     

低pH毛细管电泳法分离测定菠菜中的甜菜碱

建立了毛细管电泳法快速测定菠菜中甜菜碱的方法。通过与对溴代苯甲酰甲基溴反应,将甜菜碱转化成苯甲酰甲基酯后进行测定。研究了缓冲液的pH、分离电压以及结构相似化合物等因素对分离的影响,优化并确定了分离条件:75μm ID×50/57 cm(分离长度/总长)未涂层石英毛细管,分离电压15 kV,实验温度25℃,缓冲溶液100 mmol/L H3PO4-H3PO4盐,pH 2.91,检测波长262nm。在浓度范围5.8~580μg/mL之间,线性关系良好,y=72221x 4042.5,R2=0.9999,回收率在94.5%~99.8%之间。     

滴定法快速测定饲料中甜菜碱

甜菜碱及其盐酸盐的结构式分别为（ＣＨ３）３Ｎ＋ＣＨ２ＣＯＯ－和（ＣＨ３）３ＮＣＨ２ＣＯＯ·ＨＣｌ,分子量分别为１１７．１１和１５３．６１。它的分析方法主要有酸碱滴定法、比色法、重量法、紫外分光光度法、薄层扫描定量法、红外光谱法、气相层析法等。前三种方法的分析原理都是基于利用沉淀剂沉淀饲料中的甜菜碱而测定,由于饲料中胆碱,氨基酸等含氮物质能与沉淀剂沉淀而产生干扰。而后四种方法需要大型的仪器设备,流程长,操作繁琐。本人在前人研究的基础上,进行了快速测定饲料中甜菜碱含量的研究。１　实验部分１．１　试剂…     

甜菜碱制备工艺的研究

甜菜碱[(CH3)3N+CH2COO-],是一种季铵型水溶性生物碱,可作为甲基供体,具有促进动物蛋白质和脂肪代谢、缓和应激、调节渗透压、增进食欲、稳定维生素、参与预防球虫病 [1-3],也可作为多功能表面活性剂,广泛用于制备护发护肤用品[4-5].甜菜碱的盐酸盐可用于胃酸缺乏、动脉粥样硬化、肝脏疾病、止痛、治疗风湿病、糖尿病等[6-8].甜菜碱制备方法[9-15]有天然甜菜糖蜜提取法和化学合成法.前者由于原料来源有限而使其应用推广具有一定的局限性.传统合成方法采用氯乙酸钠和三甲胺反应,生成的氯化钠很难除去[16].近年来对此的研究如采用强阳离子交换树脂法,溶剂法或者将氢氧化钠改为氢氧化钙[17-18]等.     

枸杞半成品饮料中甜菜碱含量的测定

枸杞半成品饮料中甜菜碱含量的测定朱桂花杨高文陈晓光（宁夏大学化学工程系银川７５００２１）关键词枸杞原汁浓缩汁甜菜碱分光光度法中图分类号Ｏ６５７．３２枸杞浓缩汁是以枸杞鲜果原汁为原料生产的饮料半成品，其中约含３０％的原汁，同时为了外观、保质及口感的需要...     

Über Reaktionen mit Betainen, 19. Mitt. Über den Einfluß der Substituenten am kationischen Zentrum von Betainen auf die Bildungstendenz der Di-trifluoracetyl-N-Ylide

The influence of substituents at the ammonium nitrogen of acetic acid betaines on the reaction with trifluoracetic anhydride (TFA) has been investigated. Thus benzyl-dimethyl- and phenyl-dimethyl-betaines (1a, 1b) as well as the bifunctional betaines derived from 1,3-bis-(dimethylamino)-butane (5) or 1,4-dimethylpiperazine (7) may serve as examples. From these betaines, the symmetrical compound7 gives in 50% yield 1,4-dimethyl-piperazinium-ditrifluoracetyl-dimethylide (8), while the tendency of formation of the di-acyl-N-ylides2a, 2b, and6 is rather low.

Herrn Prof. Dr.J. Schurz, Institut für Physikalische Chemie der Karl-Franzens-Universität Graz, mit besten Wünschen zur Vollendung des 60. Lebensjahres gewidmet.     

Über Reaktionen mit Betain, 25. Mitt. Zur Chemie von Betainen aus Dihetero-Alkanen

Summary A comparative study has been performed on 1,4-oxathianium-, 1,4-dithianium- (1 and2) and 1,3-dithianium acetic acid betaine with respect to their reactivity towards haloacetic acid anhydrides and 4-nitrobenzene diazonium tetrafluoroborate. The results show that in analogy to related cyclic S-betaines the heteroalkane substituents at the cationic reaction center display an influence on reactivity.

Herrn em. Univ.-Prof. Dr. Erich Ziegler, Karl-Franzens-Universität Graz, mit herzlichen Wünschen zur Vollendung des 80. Lebensjahres gewidmet     

A Convenient Synthesis of N-Substituted 1,6-Dihydro-3(2H)-Pyridinones

N-Substituted 1,6-dihydro-3(2H)-pyridinones have been synthesised from N-substituted piperidine-3,5-diones via the methyl enol ethers. Reduction of the latter with sodium borohydride (NaBH₄) is described.     

Unsaturated Analogues of Phosphorylcholines

Abstract

The vinyl esters of phosphorus acids, containing onium group in β-position, for example, betaines type A and B (X = N, P), have a number of features, attracting to them significant atlention of researchers.^[] First of all, these compounds are interesting as examples of hydrolytically stable inhibitors of acetylcholinesteraze, posessing complex action.     

Addition of phenylisocyanate to 3,5-diphenyl-1,2-dithiolium-4-olate gives a thioketone

The Type B mesoionic heterocycle, 3,5-diphenyl-1,2-dithiolium-4-olate, reacts with phenylisocyanate producing a thioketone derivative rather than a pseudo-semi-conjugated heterocyclic mesomeric betaine. The structure of the thioketone product was confirmed by an X-ray crystallographic investigation.     

Formation of the main gas compounds during thermal analysis and pyrolysis: Betaine and betaine monohydrate

The thermochemical behaviour of betaine and betaine monohydrate was investigated under two degradation conditions. Betaine was heated up to 700°C at 10°C min^–1 in air and nitrogen flows and the evolved gas was analysed with the combined TG-FTRIR system. The evolved gas from betaine pyrolysis at 350 and 400°C was analysed by gas chromatography using mass-selective detection (Py-GC/MSD). In addition, the electron impact mass spectra of betaine and betaine monohydrate were measured.Esterification is one of the most important pyrolytic processes involving beta- ines. Even glycine betaine can change to dimethylglycine methyl ester via intermolecular transalkylation by heating. Trimethylamine, CO₂, and glycine esters were the main degradation products. Small amounts of ester type compounds evolved both in pyrolysis and with TG-FTIR. The monohydrate lost water between 35 and 260°C while the main decomposition took place at 245-360°C. The residual carbon burnt in air to CO₂ up to a temperature 570°C.This revised version was published online in November 2005 with corrections to the Cover Date.     

Syntheses and structures of Me3Sb+CH2COO−·H2O,the monohydrate of the antimony analogue of betaine,and related compounds

The syntheses of the antimony analogue of betaine, Me₃Sb⁺CH₂COO^? (1), of the precursor [Me₃SbCH₂COOH][Br] (2) and of [Me₃SbCH₂COOCH₂CH₃][Br] (3) are reported. A new method for the synthesis of solvent‐free Me₃Sb is described. The structures of 1·H₂O and 3 were determined by single crystal X‐ray diffractometry. Copyright © 2002 John Wiley & Sons, Ltd.     

Synthesis and Structural Characterization of Mono- and Di-nuclear Zinc(Ⅱ) Coordination Compounds of Triphenylphosphoniopropionate

Two novel coordination compounds of Zn(Ⅱ) with Ph3P (CH2)2CO-2(L), namely, [ZnL4(H2O)2]·(ClO4)2·2H2O(compound 1) and [Zn2Cl4(μ-L-O,O′)2](compound 2), have been prepared. The single crystal X-ray structure analysis of these compounds indicates that in compound 1 the Zn(Ⅱ) atom is coordinated by four monodentate carboxylato groups on the equatorial plane and two aqua ligands occupy the axial coordination positions. The pendant oxygen atoms form strong hydrogen bonds with the aqua molecules which results in the stability of this structure. In compound 2, two Zn(Ⅱ) atoms are bridged by a pair of carboxylato groups, showing a skew-bridge mode, and thus enabling a long Zn(Ⅱ)…Zn(Ⅱ) separation. As we know, it is a dinuclear coordination compound with the longest Zn…Zn separation.