蛋黄磷脂中磷脂酰乙醇胺的薄层扫描测定

将超临界ＣＯ２萃取法得到的蛋黄粉中的磷脂经薄层色谱分离，采用双波长薄层扫描仪对其磷脂酰乙醇胺进行测定。平均回收率为９７．６７％，ＲＳＤ为２．３１％。     

薄层扫描法测定血浆中盐酸氟桂利嗪浓度及药物动力学

血浆中盐酸氟桂利嗪经硼酸缓冲液酸化后，正戊烷－异丙醇（９８：２）提取其原型，加酸使成盐溶于无机相中，再加碱后用二氯甲烷提取，样品点于硅胶ＧＦ２５４薄层板上，以环己烷－丙酮－氯仿（９：３：５）为展开剂。氟桂利嗪在２５４ｎｍ紫外灯下呈紫色斑点，Ｒｆ＝０．５４，于ＣＳ－９３０薄层扫描仪上测定，λｓ＝２１５ｎｍ、λｇ＝３１０ｎｍ，线性范围０．３￣８μｇ，平均回收率９０．０２％。用此法测定了氟桂利嗪血药浓度     

中药白芷硫熏前后香豆素成分含量比较

用薄层扫描法对川白芷和杭白芷药材加工(硫熏)前后的香豆素类成分进行了含量测定。香豆素含量分别为0.190%、0.571%、0.178%、0.421%。     

复方广金钱草冲剂检验方法研究

应用薄层层析法，对制剂中广金钱草、黄芩、陈皮所含黄酮类成分，在同一色谱中得到的分离与鉴定，并以薄层一分光光度法对制剂中大黄所含成分大黄素进行了含量测定，方法重现性好，回收率为１００．１％，ＲＳＤ为１．０９％。     

双波长薄层扫描法测定新疆雪莲中芦丁含量

采用双波长薄层扫描法测定新疆雪莲芦丁含量。以乙酸乙酯一甲酸一水（６７：１３：２０）为展开剂，硅胶ＧＦ２５４薄层析分离；测定波长λｓ为２６３ｎｍ，参比波长λＲ为２３５ｎｍ。样品回收率为９７．３％；相对标准偏差为２．８％。在芦Ｔ０．５～６．０μｇ范围内有良好的线性，相关系数为０．９９９。本法简便、快速、灵敏度高。     

安平颗粒的质量控制研究

安平颗粒为一新研制的医院制剂,用于治疗功能性消化不良有显著疗效,为了更好地控制产品质量,本实验通过对该制剂进行定性、定量的检测手段,科学有效地控制了该制剂的质量。1处方组成黄连50g,厚朴50g,党参50g,当归75g,白术50g,干姜12g,槟榔75g,枳实50g,佛手50g,木香60g,赤芍75g,蒲公英75g,甘草50g。2制备工艺以上13味,加水提取2次,第1次加10倍水,提取1h,第2次8倍水,提取40min,过滤,合并滤液,静置48h,取上清液浓缩至相对密度1.30~1.35(90°C)的清膏,分别取清膏1份,蔗糖粉3份,糊精1份,混匀,制成颗粒干燥,制成1000g,即得。3质量控制3.1仪器与试…     

薄层扫描法测定食物中胆固醇的含量

本文探讨食物中胆固醇的薄层光密度法的测定。用硅胶Ｇ与０．３％ＣＭＣ－Ｎａ按１：２．２比例制成薄层板，石油醚－乙醚－－冰醋酸（７：３：０．１）为展开剂，５％磷钼酸乙醇溶液显色，日本岛津ＣＳ－９１０型薄层扫描仪定量扫描，测得精神异系数（ＲＤＳ％）为２．９２。稳定性变异系数（ＲＳＤ％）为２．３５，加嘏率在８７．９５－９４．２９％范围内。与气相色谱法（其回收率在９２－１０３％范围）比较，结果相接近，该法简     

The RNA helicase, nucleotide 5'-triphosphatase, and RNA 5'-triphosphatase activities of Dengue virus protein NS3 are Mg2+-dependent and require a functional Walker B motif in the helicase catalytic core

The nonstructural protein 3 (NS3) of Dengue virus (DV) is a multifunctional enzyme carrying activities involved in viral RNA replication and capping: helicase, nucleoside 5'-triphosphatase (NTPase), and RNA 5'-triphosphatase (RTPase). Here, a 54-kDa C-terminal domain of NS3 (DeltaNS3) bearing all three activities was expressed as a recombinant protein. Structure-based sequence analysis in comparison with Hepatitis C virus (HCV) helicase indicates the presence of a HCV-helicase-like catalytic core domain in the N-terminal part of DeltaNS3, whereas the C-terminal part seems to be different. In this report, we show that the RTPase activity of DeltaNS3 is Mg2+-dependent as are both helicase and NTPase activities. Mutational analysis shows that the RTPase activity requires an intact NTPase/helicase Walker B motif in the helicase core, consistent with the fact that such motifs are involved in the coordination of Mg2+. The R513A substitution in the C-terminal domain of DeltaNS3 abrogates helicase activity and strongly diminishes RTPase activity, indicating that both activities are functionally coupled. DV RTPase seems to belong to a new class of Mg2+-dependent RTPases, which use the active center of the helicase/NTPase catalytic core in conjunction with elements in the C-terminal domain.     

Induction of erythroid differentiation in K562 cells and natural killer cell-mediated lysis: distinct effects at the level of recognition and lysis in relation to target cell proliferation

The erythroleukemic K562 cell line was induced to erythroid differentiation by a variety of agents, including hemin, bleomycin, and cytosine arabinoside. The sensitivity of induced cells to binding and lysis by non-sensitized peripheral blood mononuclear cells (MNC) in agarose was studied in relation to the target cell division rate. Differentiated K562 cells formed a lower proportion of conjugates with MNC, when compared with non-induced controls. The reduction correlated significantly with the level of differentiation, irrespective of the inducer and the proliferative status. The differentiation-induced alterations of lysis, however, were strongly influenced by the modification of target cell growth rate which was caused by the differentiating agent. These data suggest that target cell differentiation has distinct effects upon the steps of recognition and lysis by natural killer cells.     

Renewal of the membrane complex of Schistosoma mansoni is closely associated with lipid metabolism

Metabolic pathways leading to lipid biosynthesis in four different developmental stages of Schistosoma mansoni were explored and quantified by incubation in the presence of labeled precursors in a chemically defined medium. At the schistosomulum stage and in male, female, or paired worms, glycerol and oleate incorporation into neutral lipids, mainly in the form of triacylglycerols, was greater than into phospholipids, whereas in 11-and 15-day-old worms, synthesis mainly led to phospholipids. Incorporation into phospholipids was recovered largely in phosphatidylcholine, and distribution into other phospholipids depended on the developmental stage. Incorporation of choline and ethanolamine into their respective phospholipids represented up to 15% of the parasitic phospholipid content. The formation of phosphatidylcholine by phosphatidylethanolamine methylation occurred mainly in the immature parasitic stages. Inositol incorporation was also measurable, whereas [14C]serine incorporation was low or undetectable. Addition of 1-palmitoyl-2-[14C]oleyl phosphatidylcholine revealed a very high uptake of this phospholipid by the immature stages but further metabolism was not detectable. In contrast, adult S. mansoni were completely unable to take up or absorb this exogenous phospholipid. The most striking aspect of this study was the relatively high metabolic activity in 11-day-old worms and the lower but sustained activity on day 15 and at the schistosomulum stage. By comparison, biosynthetic activity in adult S. mansoni, on which research studies have been focused until now, was very low. We also discuss the participation of lipid metabolism in the constant renewal of the membrane complex which is essential to parasitism by S. mansoni.