高效液相色谱法同时测定17种磺胺类药物的研究

建立了高效液相色谱-紫外法同时测定17种磺胺类药物的分析方法.主要研究了色谱柱、流动相配比对磺胺类药物分离的影响.通过研究,确定了最佳液相色谱分析条件.分离条件为:YMC ODS-C18柱;以2%乙酸溶液、乙腈和甲醇作为流动相,进行梯度洗脱;检测波长为270 nm.该方法的检测限为:磺胺胍和磺胺为2.0 ng/ml,磺胺二甲氧哒嗪、磺胺二甲基嘧啶、磺胺多辛、磺胺胍、磺胺甲基嘧啶、磺胺甲噻二唑、磺胺甲基异噁唑、磺胺甲氧哒嗪、磺胺6-甲氧嘧啶、磺胺二甲基噁唑、磺胺、磺胺吡啶、磺胺喹噁啉、磺胺噻唑和磺胺异噁唑均为5.0 ng/ml.各组分的回收率在81.3%～97.9%,相对标准偏差在0.1%～4.3%.     

高效液相色谱法测定乳清蛋白中的α-乳白蛋白和β-乳球蛋白及其改性降敏

牛乳过敏是由牛乳中的致敏蛋白引起的一种不良反应,而乳清蛋白是从牛奶中分离的高营养价值的蛋白。本研究中,笔者建立了一种高效液相色谱技术定量检测乳清蛋白中主要致敏蛋白α-乳白蛋白和β-乳球蛋白的方法;与现行标准(T/TDSTIA 007—2019)相比,本方法采用应用更广泛的Sepax-C8(4. 6 mm×150 mm,5μm)色谱柱,以0. 1%的三氟乙酸水溶液(A)和0. 1%的三氟乙酸乙腈溶液(B)作为流动相进行梯度洗脱,色谱柱在温度28℃、波长280 nm检测条件下对目标蛋白进行分离检测。定量分析结果表明,致敏蛋白在0. 125～2. 000 mg/m L范围内与蛋白峰面积线性关系良好(R2 0. 99),蛋白平均回收率为92%～96%,α-乳白蛋白和β-乳球蛋白检出限分别为0. 078和0. 090 mg/m L。该检测方法重复性好,可用于α-乳白蛋白和β-乳球蛋白的定量分析测定。此外,考察了胰蛋白酶对2种致敏蛋白改性的影响,采用智能可视化优化方法预测出酶解最优条件,结果表明在45℃下加入2000 U/g的胰蛋白酶水解30 min后,水解率高达78. 9%,2种致敏蛋白含量占牛乳总蛋白的22. 7%,大大降低了乳制品中的致敏蛋白含量。     

反相高效液相色谱法测定平邑甜茶植株内源ABA、IAA含量

用高效液相色谱法 (HPLC)分析平邑甜茶内源ABA、IAA ,选用SpherisorbC18反相柱 ,用UV检测器进行检测 ,使ABA、IAA得到很好的分离 ,测定方法迅速简便 ,流动相为甲醇、乙酸和水 ,系统研究了pH值、纯化方法对测定结果的影响 ,确定适合平邑甜茶ABA、IAA提取的分离条件。方法的精密度为 :变异系数分别为 2 83和 2 79,最低检出限 (信噪比 =2 )分别为 3 2 7和 3 2 6nmol/L ,线性范围为 50nmol/L -10 0 0nmol/L ,平均回收率为 91 9%和 92 2 %。     

高效液相色谱法测定郁金香鳞茎中3种内源激素

利用Agilent高效液相色谱仪,建立了同时测定郁金香鳞茎中GA_3、IAA、ABA 3种植物内源激素的高效液相色谱检测方法和异丙醇提取方法。采用外标法,C_(18)反相柱,流动相A(甲醇)∶B(磷酸缓冲液pH=3. 5)=45∶55;流速1 mL·min~(-1);检测波长0～3. 2 min 265 nm,3. 0～4. 5 min 212 nm,4. 5～6. 5 min 218 nm,6. 5～13. 0 min265 nm;柱温20℃进行测定;以异丙醇提取剂和二氯甲烷低温摇床提纯鳞茎中内源激素。整个过程操作简单,只需2. 0～2. 5 h可完成激素提取测定,检测方法线性相关度均在0. 995以上,测出限GA_3200 ng·mL~(-1),IAA5 ng·mL~(-1),ABA 20 ng·mL~(-1);提取方法回收率为84. 812%～95. 679%,相对标准偏差为6. 432%～2. 831%。用此方法提取郁金香的内源激素做出的图基线平稳,准确度高,可得到满意的峰形,且操作简单,各环节激素的损失较少。     

运用HPLC-MS对鸦胆子油自微乳给药系统肠吸收的研究

目的:建立高效液相色谱-串联质谱法检测油酸和亚油酸含量的方法,从而对鸦胆子油自微乳给药系统中鸦胆子油的肠吸收进行研究.方法:以甲醇-水(95∶5 v/v)为流动相,流速为0.4 mL/min,柱温为35℃作为高效液相色谱的检测条件.利用大鼠小肠膜建立体外药物扩散体系研究鸦胆子油的肠吸收特性.结果:油酸和亚油酸的保留时间分别为10.46± 0.02和8.55±0.01 min,线性范围分别为0.50～50.0 ng/mL和5.06～101.2 ng/mL,平均绝对回收率分别为97.49±3.11％和105.76± 3.13％.日间和日内精密度都小于5％.在肠吸收实验中,鸦胆子油自微乳体系中测得油酸和亚油酸含量是单独给予鸦胆子油测得量的2.8和4.1倍.结论:该方法高效、灵敏、选择性高,可以用于鸦胆子油及鸦胆子油自微乳肠吸收中油酸和亚油酸的质量测定.     

高效液相色谱法检测发酵液中木糖和木糖醇

建立高效液相色谱检测发酵液中木糖和木糖醇含量的分析方法。色谱柱为HypersilNH2 柱 (4 .6mmi.d.× 2 5 0mm ,5 μm) ,柱温 3 5℃ ,流动相为乙腈—水 (80∶2 0 ) ,流速 1 .0mL .min 1,示差折光检测器检测。木糖和木糖醇在 3 .0～ 60mg.mL 1范围内 ,峰面积与其浓度线性关系良好 (г=0 .9995 ) ;平均回收率分别为 96.0 7% (n =5 ,RSD =0 .5 1 % )和 97.47% (n =5 ,RSD =1 .1 3 % )。方法简便、快速、准确。     

高效液相色谱法分析猪屎豆种子胶多糖中的单糖组成

建立了一种采用SUGAR SP-G 0810(Pb型)糖分析色谱柱,以纯水为流动相,利用示差折光检测器的高效液相色谱外标法直接分离分析半乳甘露聚糖胶中单糖组成的方法。木糖、葡萄糖、半乳糖和甘露糖的分离在20 min内完成,检出限分别达到2.0μg,20μg,1.0μg和20μg,线性范围为2～10 mg/mL。该方法简便、快速、重现性好,用于猪屎豆种子胶多糖中单糖组分的测定,并进行回收率试验,结果5次测定的半乳糖和甘露糖的回收率分别为95.83%和103.68%,RSD分别为1.53%和1.50%。     

螺旋藻中β-胡萝卜素高效液相色谱测定方法的研究

采用高效液相色谱法直接测定螺旋藻中β-胡萝卜素组分的含量.色谱柱为YMC-pack ODS(4.6mm i.dx 150 mm,5μm),流动相为甲醇-乙腈-二氯甲烷(体积比60:30:10),在435nm波长处检测.研究结果表明:β-胡萝卜素的检测限为20ng,线性范围在4.60～36.80 mg/L,相关系数为0.9996,加样平均回收率为96.61%.方法准确、简便、快速,适用于螺旋藻及螺旋藻制品中β-胡萝卜素组分的检测.     

化妆品中苯氧乙醇和辛酰羟肟酸含量的测定方法

建立了高效液相色谱定量分析方法用于检测化妆品中苯氧乙醇和辛酰羟肟酸。以甲醇 乙腈 水溶液为流动相,InertSustain C18色谱柱分离,二极管阵列检测器检测,以保留时间和紫外吸收光谱定性外标法定量。结果表明,苯氧乙醇和辛酰羟肟酸分别在15 mg/L～2 000 mg/L(r2=0999 9)、50 mg/L～2000 mg/L(r2=09997)范围内呈良好的线性关系。检出限及定量限分别为5 mg/L和20 mg/L,样品加标回收率分别为972%～1044%、982%～1045%(RSD=15%～41%)。结果表明该方法能够精确、快捷地同时检测化妆品中苯氧乙醇和辛酰羟肟酸含量。     

高效液相色谱-柱后光化学衍生法测定变性淀粉中黄曲霉毒素含量的研究

本文采用高效液相色谱 柱后衍生法对变性淀粉中的黄曲霉毒素G2、G1、B2和B1含量进行测定。样品采用乙腈 水(84∶16,v/v)提取,经免疫亲和柱净化,C18色谱柱分离,以乙腈 甲醇 水(10∶30∶60,v/v)为流动相进行洗脱,用HPLC光化学衍生 荧光检测器检测样品含量。结果表明,4种黄曲霉毒素的标准曲线线性均大于0.999 3,回收率96%～104%,黄曲霉G2、G1、B2和B1的检出限分别为0.010 0μg/kg、0.030 0μg/kg、0.010 0μg/kg和0.030 0μg/kg。该方法操作简便,准确度高,适用于变性淀粉中黄曲霉毒素的测定。与柱前衍生法相比,该法能节省检测时间和检测成本,同时减少化学试剂对检测人员的伤害。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV