藏药蕨麻多糖的光谱性质及单糖组成分析

本研究对藏药蕨麻多糖进行了分离提纯,并测定其水溶性多糖含量为99.4%;通过紫外光谱与红外光谱分析表明,蕨麻多糖为分子量较小的α-吡喃糖,并含有氨基糖;蕨麻多糖的水解单糖经过NMP衍生后进行毛细管电泳分析,测得其单糖组成为木糖、阿拉伯糖、葡萄糖、鼠李糖、甘露糖、岩藻糖、半乳糖、葡萄糖醛酸和半乳糖醛酸,含量分别为3.945、77.445、17.568、17.646、3.942、2.165、65.268、13.037μg/mg和33.484μg/mg,与GC-MS的定性分析结果一致。     

马齿苋多糖的研究

用苯酚硫酸法对马齿苋多糖含量进行测定,设计正交实验确定马齿苋多糖提取的最佳工艺,马齿苋多糖的提取率高达9.23%。将其多糖分离纯化,进行理化性质试验测试,利用纸层析和气相色谱对马齿苋多糖中的单糖组成做了分析,马齿苋多糖中的单糖组成有葡萄糖、半乳糖、甘露糖、果糖、木糖、阿拉伯糖。     

海蒿子多糖DEⅠ、DEⅡ组分分离纯化、结构及抗癌活性研究

海蒿子干粉经热水抽提、乙醇沉淀、DEAE-Sephadex A-25柱层析分离,得到多糖DEⅠ、DEⅡ,总糖含量分别为52.40%、38.8%.经酸降解、薄层层析、气相色谱-质谱分析,证明其单糖组成均为木糖、岩藻糖、半乳糖、果糖、甘露糖、葡萄糖.其中岩藻糖含量最高.多糖DEⅠ、DEⅡ对P388肿瘤具有抑制活性.     

荔枝壳多糖特性研究

多糖是荔枝壳的重要活性成分,本研究采用阴离子交换柱和凝胶过滤柱对荔枝壳多糖进行分离纯化。凝胶渗透色谱测定其分子量为14000 Dal。通过气相色谱测定其单糖组成为甘露糖、半乳糖和少量的阿拉伯糖,分子链由1,2键、1,3键和1,6键组成,不含1,4键。红外光谱分析表明甘露糖以β-D-甘露糖形式存在,不含羧基基团。     

高效液相色谱法联用蒸发光散射测定薏苡仁多糖的单糖组成

建立高效液相色谱法(HPLC)联用蒸发光散射(ELSD),对薏苡仁多糖的单糖组成进行测定。HPLC色谱条件:Supelco~?APHERA NH_2 Polymer色谱柱(150 mm×2 mm,5μm);流动相:乙腈-0.05 mol/L醋酸铵溶液(体积比为85∶15);流速:0.2 mL/min;进样量:10μL;柱温:35℃;ELSD检测条件:漂移管温度为60℃,载气流量为1.6 L/min。研究结果表明:甘露糖(mannose)、半乳糖(galactose)、葡萄糖醛酸(glucuroaicacid)、鼠李糖(rhamnose)、半乳糖醛酸(galacturonic acid)、葡萄糖(glucose)、阿拉伯糖(arabirose)和岩藻糖(flucose)的进样量对数与峰面积对数在一定范围内均呈现出较好的线性关系(0.999 1～0.999 9),回收率均在97.4%～100.4%,RSD均小于2%。研究表明该方法准确可靠,分离效果好,可用于测定薏苡仁多糖的单糖组成。     

HPLC法测定新疆贯叶连翘中绿原酸和芦丁的含量

采用液相色谱法测定贯叶连翘中绿原酸和芦丁含量。用Hyperil ODS色谱柱(12.5 cm×6.0 mm i.d.,5μm)进行分离。流动相为甲醇-1%冰醋酸梯度洗脱,流速为0.6 mL/min。检测波长为343 nm。绿原酸线性范围为0.0076~0.3040μg,相关系数R=0.9997。芦丁线性范围为0.312~3.120μg,相关系数R=0.9999。样品的平均回收率分别为101.2%,99.8%。此方法准确、快速,适用于绿原酸和芦丁的定量分析。     

金樱子多糖单糖组成的TMS柱前衍生化/GC-MS研究

探讨金樱子多糖的含量及其单糖组成,为金樱子质量评价及临床用药提供参考依据。本文采用水提-醇沉法获得金樱子多糖,以葡萄糖为标准品,蒽酮-硫酸比色法测定多糖含量;多糖酸解后经三甲基硅烷(TMS)衍生化,以标准品单糖为对照,采用气-质联用法(GC-MS)测定多糖的单糖组成。结果表明,本实验条件下,测得金樱子多糖提取得率为29.38%;金樱子多糖中单糖由阿拉伯糖、鼠李糖、木糖、甘露糖、半乳糖、葡萄糖、果糖组成,其中葡萄糖、甘露糖、果糖和半乳糖在金樱子多糖中占比较大,分别为65.03%、7.36%、16.11%及8.87%。     

高效液相色谱法同时测定儿童血清中视黄醇、25-OH-维生素D3和α-生育酚浓度

目的:建立能同时测定儿童血清中视黄醇、25-OH-维生素D3和a-生育酚的高效液相色谱(high performance liquid chromatography,HPLC)法.方法:以无水乙醇沉淀蛋白质后,血清中的脂溶性维生素用正己烷提取,吹氮气浓缩后用HPLC测定.结果:视黄醇、25-OH-维生素D3和a-生育酚的线性范围分别为0.015-500μg/mL、0.012-500μg/mL和0.1-500 μg/mL;检出限分别为0.015μg/mL、0.012μg/mL和0.1μg/mL;相对标准偏差分别为0.98%、2.09%和4.63%.三种脂溶性维生素各个浓度的提取回收率均大于80%,方法回收率均大于90%.结论:本法简便快速,适于血清样品中视黄醇、25-OH-维生素D3和a-生育酚三种脂溶性维生素的同时测定.     

离子色谱法测定ACYW135群脑膜炎球菌结合物中Y群及W135群多糖含量

目的利用离子色谱法即高效阴离子交换柱层析—脉冲安培检测法(HPAEC-PAD),测定ACYW135脑膜炎球菌多糖蛋白结合物中Y群和W135群多糖含量的方法,并加以验证。方法将ACYW135脑膜炎球菌多糖蛋白结合物中Y群和W135群多糖用三氟乙酸(TFA)水解为特异性单糖(葡萄糖、半乳糖),并去除水解液中残留的TFA,用HPAEC-PAD分析检测,用PA10糖分析柱分离单糖,电化学检测器测定葡萄糖及半乳糖含量,用Chromeleon色谱工作站记录并分析数据。对上述方法进行专属性、准确性、重复性验证,确定该方法的检出限和定量限。结果 Y群和W135群多糖在TFA2.5 mol/L(终浓度)、90℃、4 h可完全水解为葡萄糖、半乳糖。对照品葡萄糖及半乳糖在0.10~60.00μg/m L范围内,质量浓度和色谱峰面积呈较好的线性关系,r均大于0.99,回收率为87.94%~109.80%,相对标准偏差(RSD)为1.00%~2.00%,检出限为0.05μg/m L(信噪比3∶1),定量限为0.10μg/m L(信噪比10∶1)。结论离子色谱法可同时检测脑膜炎球菌多糖蛋白结合物中Y群和W135群糖含量,该方法操作简便、灵敏、快速,干扰小,重现性好,适用于对相关疫苗生产过程中的质量控制。     

轻度降解核磁共振法研究多糖链结构

 建立了轻度降解~(13)C核磁共振法研究多糖结构的方法。美国瓜胶和国产胶1在70℃下用90％甲酸降解3小时。用Bio-Gel p-4的凝胶色谱分离。含20个以上糖残基的片断为主要降解成份。用~(13)C核磁共振法研究,确定它们都是具有以β1-4甘露糖为骨架,其中某些甘露糖的6位碳有α-半乳糖侧链的结构。这些结果与组成分析和甲基化分析结果一致。     

分散固相萃取剂-液相色谱串联质谱法测定鸡肉和鸡蛋中氟苯尼考和氟苯尼考胺残留

建立分散固相萃取剂-液相色谱串联质谱法(HPLC-MS/MS)同时检测鸡肉及鸡蛋中氟苯尼考和氟苯尼考胺的方法.样品用乙腈提取,C18分散固相萃取填料净化,乙腈饱和的正己烷脱脂,电喷雾离子源正负模式切换,HPLC-MS/MS多反应监测(MRM),同位素内标法定量.氟苯尼考和氟苯尼考胺线性范围分别为0.1 ng/mL～2....     

食药用菌功能性β-葡聚糖荧光法测定研究

以酵母功能性β-1,3/1,6-葡聚糖为对照品,利用苯胺蓝和β-1,3/1,6-葡聚糖特异结合荧光特性,研究了葡聚糖荧光法测定时的各影响因素,建立了荧光法测定食药用菌功能性β-葡聚糖的方法。pH9.6缓冲液,80℃条件下避光反应15min,室温30min冷却后,398nm激发波长,508nm发射波长,20℃下进行荧光测定。在测定浓度2-20μg/mL范围内,荧光强度与浓度具有良好的线性关系(R2=0.9977),其中检出限为45μg/L,测定精密度和加样回收率良好,相对标准偏差(RSD)分别为1.86%和3.40%,并与酶法进行了比对验证,一致性良好,且荧光法更为节约时间和成本,并对灰树花菌、巴氏蘑菇、香菇和鲍氏针层孔菌四种食药用菌β-葡聚糖提取样品进行了葡聚糖纯度和提取率测定。     

CarboPac PA20: a new monosaccharide separator column with electrochemical detection with disposable gold electrodes

This report documents the development of a new monosaccharide separator column (CarboPac PA20, 3×150 mm) that allows fast, efficient monosaccharide separations with good spacing. It is based on a new chemistry with a reduced resin particle size (from 10 to 6.5 μm). Faster, more efficient separations of glycoprotein monosaccharides with better spacing were achieved across a range of isocratic NaOH concentrations at lower flow rates. Detection sensitivity was improved, enabling routine low to sub pmol monosaccharide determinations. Glycoprotein monosaccharides eluted in less than 10 min at a flow rate of 0.5 ml/min. Furthermore, when used with an AminoTrap guard column, the protein matrix consisting of amino acids and peptides (released by acid hydrolysis of glycoprotein) did not interfere with monosaccharide analysis. Compared to previous CarboPac columns (CarboPac PA1 and CarboPac PA10), the CarboPac PA20 has improved selectivity with respect to glycoprotein monosaccharides. The improved selectivity results in better separation of glucosamine and galactose, enabling the accurate determination of monosaccharide ratios for undergalactosylated glycoproteins. Finally, disposable gold working electrodes that eliminate the possibility of working electrode recession affecting peak area response were used.     

Single laboratory evaluation of a planar waveguide-based system for a simple simultaneous analysis of four mycotoxins in wheat

The accuracy and precision of a commercially available system based on an indirect competitive immunoassay and planar waveguide technology was evaluated for the analysis of deoxynivalenol (DON), ochratoxin A (OTA), zearalenone (ZEAR), and T-2 toxin in wheat. The system generally performed well at the tested concentrations that were close to the regulatory limits of DON and OTA in wheat. The mean percent recovery of OTA from certified and in-house reference materials ranged from 90 to 111 %, with a relative standard deviation of 8–16 % (at 4.2, 4.9, and 7.0 μg/kg). Mean percent recoveries of DON ranged from 75 to 103 %, with a relative standard deviation of 14–20 % (at 610, 940, and 1300 μg/kg). As analyte concentrations approached the lower limits of the working range of 3 μg/kg OTA and 400 μg/kg DON, the mean percent recoveries and relative standard deviation increased for both DON and OTA. A lack of reference materials precluded a thorough evaluation of the method for the analysis of ZEAR and T-2. The particular strength of the technology was that multiple mycotoxins were analyzed simultaneously.     

Residue analysis of organophosphorus and organochlorine pesticides in fatty matrices by gas chromatography coupled with electron-capture detection

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v:v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4'-DDE (44.6-50.4%), 4,4'-DDE (51.1-57.5%) and 2,4'-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.     

A single column packing for the gas-liquid chromatographic separation of various biologically important compounds.

The use of a single, commercially available column packing, TabsorbR, is described for the g.l.c. separation of a large number of different compounds. The resolution of the homologous members of the following series of compounds was achieved: (1) saturated fatty acids (C1-C18), (2) normal aliphatic saturated dicarboxylic acids (C2-C14), (3) normal aliphatic saturated alcohols (C1-C24), (4) normal aliphatic saturated amines (C1-C12), (5) the common amino acids except arginine, histidine and cysteine, (6) aliphatic hydrocarbons (C10-C20) and (7) monosaccharides. It should be noted that twenty-two monosaccharides including three hexosamines and two anhydrohexoses, could be resolved as alditol acetates in a single run. In addition, galacturonic, glucuronic and iduronic acids could be separated from one another as their 1,4-lactones. The resolution achieved in these series of compounds was found to be consistent and highly reproducible. It is of further interest that certain isomers of the higher fatty acids and hydrocarbons with one double bond could also be separated from the normal and saturated compounds, respectively. The applicability of "Tabsorb" for the g.l.c. separation, although noted above to be considerably broad, is by far not yet exhausted. These procedures which form the basis for the quantitative determinations of the various compounds studied as demonstrated by analysis of glycopeptides for neutral hexoses and proteins for the amino acids, can readily be adapted to preparative methods. From the biochemical point of view "Tabsorb" is an extremely versatile column packing in that it can be used for the identification of many of the common building blocks of natural products.     

Separation/Preconcentration Methods for the Determination of Aluminum in Dialysate Solution and Scalp Hair Samples of Kidney Failure Patients

A new method is reported for the separation of aluminum ions (Al(3+)) from interfering cations in pharmaceutical and biological samples through solid-phase extraction (SPE) using 2-methyl-8-hydroxyquinoline (8-hydroxyquinaldine) on activated silica. While separated Al(3+) was preconcentrated by cloud point extraction (CPE) using 3,5,7,2'-4'-pentahydroxyflavone (morin) as complexing reagent, the resulting complex was entrapped in nonionic surfactant (Triton X-114) as prior step to its determination by spectrofluorimetry (SPF). The validity of separation/preconcentration of Al(3+) was checked by certified reference material of human hair and standard addition method. The chemical variables affecting the analytical performance of the separation/preconcentration methods were studied and optimized. The enrichment factor and detection limit of Al(3+) for the preconcentration of 10?ml of dialysate solution and acid-digested samples of scalp hair samples were found to be 25 and 0.34?μg/L, respectively. The relative standard deviation for six replicates of standard containing 20?μg/L of Al(3+) was <10%. In all DS, the concentration of Al was >10?μg/L. The level of Al in scalp hair samples of kidney failure patients was higher than healthy controls.     

Thermodynamics of the interaction of RbCl with some monosaccharides (D-glucose, D-galactose, D-xylose, and D-arabinose) in aqueous solutions at 298.15K

The Gibbs energy interaction parameters of RbCl with some monosaccharides (D-glucose, D-galactose, D-xylose, and D-arabinose) in water, g(ES), were obtained from electromotive force (emf) measurements of the electrochemical cell without liquid junction and containing two ion-selective electrodes (ISE): K-ISEmid R:RbCl(m(E))mid R:ISE-Cl and K-ISEmid R:RbCl(m(E)),saccharide (m(S))mid R:ISE-Cl, at 298.15K. The enthalpy interaction parameters of RbCl with these monosaccharides in water, h(ES), are determined according to the McMillan-Mayer theory from the measurements of the enthalpies of mixing of aqueous RbCl solutions with aqueous monosaccharide solutions, as well as the enthalpies of dilution of RbCl and monosaccharide solutions in pure water at 298.15K by a calorimetric method. Furthermore, the entropy interaction parameters, s(ES), can be evaluated through g(ES) and h(ES). The results suggest that the electrostatic interactions of these monosaccharides with RbCl in water are predominant compared with structural interactions, and these parameters are controlled primarily by the stereochemical structure of the monosaccharides in water.     

顺反式肉桂醛对肉源隆德假单胞菌生物被膜和致腐性的抑制作用

【目的】为比较反式和顺式肉桂醛对肉源假单胞菌生物被膜和致腐性的影响。【方法】通过平板计数测定两种肉桂醛对隆德假单胞菌的最小抑菌浓度(MIC),结晶紫法、珠涡流法、激光共聚焦显微镜观察、福林法等检测亚抑菌浓度肉桂醛处理下隆德假单胞菌生物被膜形成、运动性和胞外酶活性变化。荧光定量RT-PCR检测肉桂醛对隆德假单胞菌粘附lapA、鞭毛fliC、蛋白酶aprX和脂肪酶lip基因表达量的影响。【结果】反式和顺式肉桂醛对隆德假单胞菌的MIC分别为200μg/mL和225μg/mL,1/8 MIC、1/4MIC、1/2MIC亚抑菌浓度肉桂醛显著降低隆德假单胞菌生物被膜结晶紫和粘附性,其中1/2MIC反式和顺式肉桂醛处理下被膜分别减少60.27%和52.05%,菌体粘附降低56.35%和61.10%。亚抑菌浓度肉桂醛显著减少被膜厚度,反式肉桂醛还能显著杀灭被膜菌。且肉桂醛能显著抑制菌体的泳动性,反式肉桂醛对生物被膜和泳动性的抑制效果更强。肉桂醛还能抑制隆德假单胞菌蛋白酶和脂肪酶活性,其中1/2MIC反式和顺式肉桂醛处理下菌体蛋白酶分别减少61.90%和76.19%,脂肪酶降低40.17%和47.01%。且发现肉桂醛显著降低lapA、fliC、aprX和lip表达量,其中1/2MIC反式和顺式肉桂醛分别降低4个基因表达量至对照组的0.05–0.16和0.02–0.12倍。【结论】两种亚抑菌浓度肉桂醛异构体显著抑制隆德假单胞菌生物被膜和致腐性,其中反式肉桂醛对生物被膜抑制较强,而顺式肉桂醛更有效地降低致腐酶活性,其与肉桂醛下调相应基因表达密切相关。     

Quantification of corticosteroids in bovine urine using selective solid phase extraction and reversed-phase liquid chromatography/tandem mass spectrometry

This paper presents the development of a simple liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to determine corticosteroids in bovine urine sample matrices. This method uses a single phase extraction (SPE) for cleaning of the sample with an Oasis MAX cartridge at pH 9.0–9.5 and elution by a neutral organic solvent (acetonitrile/dichloromethane), followed by separation on a GEMINI C18 column in the gradient mode with acetate buffer (pH 4.1)/methanol. A triple quadrupole mass spectrometer equipped with a multimode ion source, set to negative atmospheric pressure chemical ionization (APCI) in the multiple reaction monitoring mode was used for detection. The main advantage of this method over other commonly used methods includes the use of SPE with a low volume cartridge for sample preparation and no ion suppression effects from matrix components of the urine samples in the LC–MS/MS analysis. This allowed a reduction the quantification limits (decision limits, CCα) for the first time to 0.1 μg/L (1 and 0.2 μg/L for triamcinolone and flumethasone, respectively). The developed method was validated in accordance with the European Union Commission Decision 2002/657 EC. The recoveries and within-laboratory reproducibility varied from 77% to 115% and 87% to 107.5%, respectively, at 2, 3, and 4 μg/L levels of corticosteroids. The relative standard deviation (RSD) of the measurements was lower than 30%. The decision limit was calculated by multiplying the signal-to-noise ratio by 3 and the obtained values were in the range of 0.1–1.0 μg/L, confirmed by the analysis of twenty blank samples, which were spiked at the desired concentrations. The detection capability was calculated by the addition of the decision limit and the standard deviation followed by multiplication by 1.64 of the within-laboratory reproducibility at 2 μg/L of corticosteroids. The method was applied to four urine samples, giving concentrations of prednisolone (PRED) residues in the range from 0.3 to 0.9 μg/L.