魔芋中神经酰胺类物质的HPLC-ELSD分析及其含量测定

建立高效液相色谱-蒸发光散射检测器分析神经酰胺的方法并进行了含量的测定.色谱柱:ZORBZX Eclipse XDB-C18(4.6mm×250mm,5μm),洗脱方法:梯度洗脱,柱温:35℃,流动相:甲醇/水,流速:1ml/min;检测器:蒸发光散射检测器,漂移管温度:40℃,氮气流速:1.5L/min.系统探讨了梯度洗脱的起始浓度、洗脱的时间和洗脱梯度的程序设置,最佳的梯度洗脱条件为5min内,甲醇浓度从60%线性增加为90%,从5min到25min,甲醇浓度线性增加为95%,在此条件下样品和标准品的分离色谱峰对称性较好.随后测定了各种样品中神经酰胺的含量,并进行了方法学验证,结果神经酰胺在0.2～2μg之间线性关系良好,最低检测限为0.01mg/ml,R2=0.9992;平均回收率为93.3%,RSD=1.65%(n=5).本法灵敏、方便、准确,重现性好,可用于魔芋神经酰胺类物质的分离及其含量的测定.     

单棕榈酰莽草酸的高效液相色谱-蒸发光散射检测法定量测定

本文建立一种采用高效液相色谱-蒸发光散射检测法定量测定单棕榈酰莽草酸的方法。色谱条件:色谱柱:反相Symmetry C18柱4.6×250 mm i.d.(填料粒度5μm),柱温30℃,流动相:乙腈-水-甲酸(80∶20∶0.2);流速0.8 mL/min;ELSD漂移管温度:80℃,载气流速:2 L/min。3-,4-和5-棕榈酰莽草酸纯品采用酶法合成,合成产物经柱层析和高效液相色谱制备纯化得到纯品。在该色谱条件下,3-,4-和5-棕榈酰莽草酸在0.21~4.12μg的范围内,其质量与其峰面积线性关系良好(r=0.9991,0.9998,0.9997),回收率分别为95.2~98.7%,96.1%~98.2%,96.3%~98.5%;RSD分别为1.6%,1.8%,1.9%。实验结果表明该方法具有简便、快速、准确、重现性较好的特点,可以用于定量分析单棕榈酰莽草酸,尤其适用于非水相酶促反应合成体系中的产物检测。     

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。     

藤黄灰链霉菌-H103发酵液中抗真菌活性成分的分离纯化*

通过大孔树脂吸附等方法对藤黄灰链霉菌H103发酵液中的抗真菌活性成分进行了分离纯化,得到了纯度较高的活性物质的结晶,并且建立了通过大孔树脂吸附-结晶的分离纯化路线以及反相高压液相色谱-蒸发光散射(HPLC-ELSD)的检测方法,为进一步的理化性状研究打下了一个良好的基础。实验表明,最佳吸附树脂为X-5树脂,洗脱剂为50%乙醇,HPLC条件为:反相色谱柱Agilent 20RBA×310SB-C18(150mm×4.6mm I.d,5μm),以乙腈(A)-水(B)为流动相,梯度洗脱,0~4.0m in,V(     

超高效液相色谱-串联质谱法检测小菜蛾血清中的β-蜕皮激素

【目的】研究建立可以准确检测小菜蛾血清中痕量β-蜕皮激素的超效液相色谱-串联质谱(UPLC-MS/MS)分析法。【方法】小菜蛾血清β-蜕皮激素样品用乙腈提取并进行蛋白沉淀,以C18色谱柱分离,经UPLC-MS/MS检测,以芸苔素内酯为内标物,内标法定量。【结果】结果表明,在0.5-50μg/L浓度范围内β-蜕皮激素线性相关系数R~2=0.9998;在0.5、10和50μg/L3个添加水平下的平均回收率在91.9%-104.9%之间,相对标准偏差(RSDS,n=5)在3.2%-9.2%之间;方法的定量限为0.5μg/L。【结论】该方法具有操作简单、灵敏度高,稳定性好,应用性强等优点,可为昆虫血清中的β-蜕皮激素检测提供科学准确的方法。     

藤黄灰链霉菌-H103发酵液中抗真菌活性成分的分离纯化

通过大孔树脂吸附等方法对藤黄灰链霉菌H103发酵液中的抗真菌活性成分进行了分离纯化,得到了纯度较高的活性物质的结晶,并且建立了通过大孔树脂吸附-结晶的分离纯化路线以及反相高压液相色谱-蒸发光散射(HPLC-ELSD)的检测方法,为进一步的理化性状研究打下了一个良好的基础。实验表明,最佳吸附树脂为X-5树脂,洗脱剂为50%乙醇,HPLC条件为:反相色谱柱Agilent 20RBA×310SB-C18(150mm×4.6mm i.d,5μm),以乙腈(A)-水(B)为流动相,梯度洗脱,0~4.0m in,V(A):V(B)=20∶80,4.0~9.5m in,V(A)∶V(B)=45∶55,此后V(A):V(B)=80∶20,流动相流速:0.8mL/m in,柱温:30℃,ELSD条件:漂移管温度115℃,载气流速(空气)2.3L/m in。     

HPLC-ELSD法测定消栓通颗粒中黄芪甲苷的含量

目的:建立测定消栓通颗粒中黄芪甲苷含量的新方法.方法:采用高效液相色谱-蒸发光散射检测法测定,色谱柱为kromasilC18柱,以乙腈-水(32:68)为流动相,流速为1.0ml/min,ELSD条件为飘逸管温度为105℃,载气流速为2.5L/min;测定消栓通颗粒中黄芪甲苷的含量.结果:黄芪甲苷在1.08μg-6.48μg范围内与峰面积线性关系良好(r=0.9999),平均加样回收率为100.2%,RSD为0.93%.结论:方法灵敏、可靠、准确、重复性好,可作为消栓通颗粒的质量控制方法.     

高效液相色谱法测定17AA氨基酸注射液中N-乙酰-L-半胱氨酸和N-乙酰-L-酪氨酸

建立了一种用高效液相色谱测定 17AA氨基酸注射液中N 乙酰 L 半胱氨酸和N 乙酰 L 酪氨酸含量的方法。样品经稀释后 ,直接上机测定 ,其色谱条件为 :WatersSymmetryC18色谱柱 ,流动相为 8.5mmol/LNaAc - 5 %CH3 OH (pH =4.0 ) ,柱温36℃ ,流速 1.0ml/min ,检测波长 195nm ,N 乙酰 L 半胱氨酸在 5 .4mg/L到 5 40mg/L、N 乙酰 L 酪氨酸在 4.9mg/L到 490mg/L之间 ,标准曲线呈良好的线性关系 (r2 >0 .9999)。该方法具有良好的重现性 ,日内相对标准偏差小于 3% ,日间相对平均误差小于 7% ,样品回收率在 90 %～ 110 %之间。该方法与测定氨基酸注射液的其它高效液相色谱法相结合 ,能够对 17AA氨基酸注射液中所有氨基酸成分进行全面检测。     

HPLC-ELSD法在刺五加药材糖类成分分析中的应用

建立一种高效、快速的高效液相色谱—蒸发光散射检测法(HPLC-ELSD)分析刺五加药材中糖类成分—葡萄糖及蔗糖组分。采用CHROMATOREX NH2柱为固定相;以乙腈：水为84.5：15.5(V/V)为流动相,流速1.0 mL·min^-1;漂移管温度为100℃;氮气流速为2.5 L·min^-1。在上述色谱条件下,葡萄糖和蔗糖的线性范围分别为0.023 2～0.116 0 mg·mL^-1及0.099 6～0.496 5 mg·mL^-1;且该二种糖的检测限分别（信/噪=3）为3.87 ng和3.31 ng。本方法无须进行糖衍生化而直接用于刺五加药材中糖类成分的分离分析。     

基于半理性设计提高疏棉状嗜热丝孢菌脂肪酶催化特异性

甘油二酯(diacylglycerol,DAG)是油脂代谢的中间产物,在人体中具有重要的生理功能,主要通过脂肪酶水解油脂制备。但对1,2-甘油二酯(1,2-diacylglycerol,1,2-DAG)、1,3-甘油二酯(1,3-diacylglycerol,1,3-DAG)的检测分离方法及脂肪酶的催化特异性的研究较少,限制了其广泛应用。基于以上问题,本研究首先通过超临界流体色谱与蒸发光散射检测器联用,优化检测分析参数,建立了1,2-DAG(0.025–0.200 g/L)和1,3-DAG(0.025–0.150 g/L)的高效定量检测方法。进一步基于疏棉状嗜热丝孢菌脂肪酶(Thermomyces lanuginosus lipase,TLL)与三油酸甘油酯的分子对接,挑选了5个潜在底物结合位点并通过定点饱和突变构建了突变体库,利用超临界流体色谱方法对突变体催化特异性进行筛选。突变文库中I202V表现出最高的1,3-位置选择特异性,较野生型TLL提高了11.7%。本文基于半理性设计方法实现了对TLL位置催化特异性的改造,并建立了一种能够高效分离检测DAG位置异构体的方法,为脂肪酶催化特异性研究提供了参考。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.