HPLC检测三叶青块根中白藜芦醇和白藜芦醇苷含量的研究

目的：建立三叶青地下部分白藜芦醇、白藜芦醇苷以及总黄酮的提取分离和含量测定方法。方法：白藜芦醇提取分离选取溶剂为70%乙醇，白藜芦醇苷的提取分离选取溶剂为40%乙醇。含量测定采用高效液相色谱法，色谱柱选择Agilent ZORBAX SB-C18色谱柱(250 mm×4.6 mm,5μm)，流动相为甲醇-水梯度洗脱，流速为0.8 mL/min，检测波长为304 nm，柱温25℃。结果：白藜芦醇的线性关系方程为Y=113.836X+0.911 5，在0.02～2μg/mL范围内的峰面积与进样浓度线性关系良好(R²=0.997 6)。采用70%乙醇提取三叶青根茎中白藜芦醇的平均含量为0.59μg/g。白藜芦醇苷的线性关系方程为Y=52.515X-0.497 7，在0.02～2μg/mL范围内的峰面积与进样浓度线性关系良好(R²=0.994 4)。采用40%乙醇提取三叶青根茎中白藜芦醇的平均含量为1.76μg/g。结论：建立了三叶青地下部分白藜芦醇、白藜芦醇苷以及总黄酮的提取分离和含量测定方法。建立的高效液相色谱法方法简便，准确，重复性好，可应用于...     

高效液相色谱法测定山楂叶中熊果酸含量的研究

本文建立了一种可靠性高、重现性好的高效液相色谱(HPLC)测定山楂叶中熊果酸含量的方法,在测定中采用富集和固相萃取组合纯化工艺去除干扰物质。高效液相色谱测定条件为Hypersil(ODS)色谱柱,流动相为甲醇:0.2%磷酸二氢钠(90∶10,V/V),检测波长210nm,流速0.8mL/min。熊果酸浓度在100~800μg/mL与峰面积存在良好线性关系(r2=0.9992),该方法准确可靠,日内稳定性标准偏差在0.6%~1.5%,日间稳定性标准偏差在0.7%~2.6%。为不同产地山楂叶中熊果酸含量建立有效的分析方法。     

白藜芦醇软膏剂的制备及含量测定

为了制备一种质地均匀、含量稳定的白藜芦醇外用软膏剂,本研究采用正交设计,以外观性状、离心稳定性、热稳定性、冷稳定性为指标,考察了软膏剂配方及制备工艺,并建立高效液相检测方法检测软膏剂中白藜芦醇含量。结果表明,白藜芦醇软膏剂最佳配方为油相硬脂酸6 g,凡士林3 g,单硬脂酸甘油酯1.2 g,液体石蜡9 mL,三乙醇胺0.15 mL;水相:纯净水16.5 mL十二烷基硫酸钠0.075 g,甘油3 mL,月桂氮卓酮0.03 g。乳化方法为油相加入水相中,乳化温度为85℃,建立的高效液相色谱法表明,白藜芦醇在3.075~49.2μg/mL范围内,峰面积与其浓度线性关系良好(R~2=0.999 4),平均回收率为99.24%。本研究制备了一种性状均匀,稳定性良好,有效成分可控的白藜芦醇软膏剂,为白藜芦醇临床应用提供了新的剂型。     

高效液相法测定香菇菇柄麦角甾醇的含量

采用高效液相色谱法(High performance liquid chromatography,HPLC)建立了测定菇柄麦角甾醇的含量测定方法。确定提取过程中皂化剂的种类和醇碱比后,将样品皂化,萃取后蒸干溶剂,乙醇定容测定。采用Phe-nomenex-C18色谱柱,V(流动相甲醇)∶V(水)=98∶2,流速1.0 mL/min,检测波长282 nm。结果表明:麦角甾醇线性回归方程为Y=9E+9×106X-8919.9(X:质量浓度,mg/mL),R2=0.998 9,0.01~0.30 mg/mL范围内线性关系良好,回收率为97.31%~101.95%。与紫外分光光度法所测结果比较,HPLC法测定菇柄中麦角甾醇含量灵敏、快速、准确,适用菇柄中麦角甾醇的含量测定。     

RP-HPLC测定红丝线中香豆素的含量

采用反相高效液相色谱法,测定红丝线中香豆素的含量。色谱柱为ZORBAXXDB-C18(4.6mm×150mm,5μm);流动相:V(甲醇)∶V(0.01mol/L磷酸二氢钠溶液(pH5.4))=45∶55;流速:1mL/min;检测波长278nm。香豆素的线性范围为2.5~30mg/L(r=0.9998),回收率97.5%~101%。该法简便、准确,重复性好,适用于测定红丝线中香豆素的含量。     

花生中白藜芦醇和白藜芦醇苷的提取及含量测定

建立高效液相色谱紫外法同时测定花生中白藜芦醇和白藜芦醇苷含量的方法。以85%乙醇水溶液为提取剂,采用直接超声提取、高速匀浆提取和固相萃取3种不同提取方法处理花生样品,对提取剂使用量和提取方法进行比较研究,高效液相色谱法进行含量测定。结果表明：当提取剂使用量为40mL时,固相萃取提取法效果最好,白藜芦醇的加标回收率为96.00%~109.55%,相对标准偏差（RSD）为1.64%~2.17%,检出限为0.016mg/kg;白藜芦醇苷的加标回收率为91.82%~104.67%,相对标准偏差（RSD）为1.73%~2.81%,检出限为0.052mg/kg。测定的山东省210个花生样品中白藜芦醇含量为0.17~11.39mg/kg,含量最低的是花育22,最高的是白玉品种;白藜芦醇苷含量为0.22~1.44mg/kg,含量最低的是春甜,最高的是山花9号品种。该方法适合于花生样品中白藜芦醇和白藜芦醇苷含量的测定。     

凝胶柱层析分离虎杖中白藜芦醇的研究

本论文初步探讨了虎杖中白藜芦醇分离纯化的工艺条件,比较了不同溶剂、不同浓度、不同流速洗脱条件下白藜芦醇样品在LH-20凝胶层析柱上的分离效果,以及虎杖的乙醇提取液通过氯仿、乙酸乙酯萃取,凝胶柱层析分离后的成分变化,实验表明,当以甲醇为洗脱液,浓度为60%,流速为0.5 mL/min时,白藜芦醇样品的分离效果最好.采用中压液相色谱检测收集到的白藜芦醇纯度(以白藜芦醇峰面积占总峰面积计算)可达80.34%,回收率达86.16%.     

HPLC法测定花生根中白藜芦醇的含量

本文采用反相高效液相色谱法测定了花生根中白藜芦醇的含量.选用ODS-C18色谱柱(200 mm×4.6mm,5μm),以甲醇-水(4555)为流动相,流速为0.5 mL/min,紫外检测波长为303nm.结果表明,白藜芦醇峰面积与其浓度之间呈现良好的线性关系,线性回归方程为Y=15879.28X+12350.2,相关系数为0.9996.方法简单,快速,精密度好,回收率为98.8%,相对标准偏差为1.79%.     

HPLC法测定小叶山葡萄叶中白藜芦醇含量

建立一种高效液相色谱法(HPLC)测定小叶山葡萄Vitis thunbergii var.taiwaniana叶中白藜芦醇含量的检测方法。Waters高效液相色谱仪:Hypersil C18色谱柱(250 mm×4.6 mm,5μm);流动相:甲醇-水(72:28);流速:1 mL·min^-1;检测波长306 nm。结果表明,在上述色谱条件下,白藜芦醇含量在10~200μg·mL^-1范围内线性关系良好,相关系数r为0.9999。精密度、重现性、稳定性的RSD(n=5)分别为0.77%、0.41%、0.21%;平均加标回收率为99.92%,相对标准偏差为0.39%。该方法准确、灵敏、可靠,可用于白藜芦醇的定量和定性分析。     

HPLC法测定芦笋茎秆中芦丁、槲皮素及白藜芦醇含量

为了建立高效液相色谱法对芦笋茎秆中芦丁、槲皮素和白藜芦醇含量的测定方法。采用不同方法提取芦笋茎秆中的芦丁、槲皮素和白藜芦醇,得出甲醇法提取芦丁、甲醇-HCl法提取槲皮素以及乙醇法提取白藜芦醇得率最高;确定了高效液相色谱法对3种物质的最佳色谱条件为流动相:芦丁为0.2 mol/L乙酸钠-甲醇(Me-OH∶H2O=35∶65)溶液(用磷酸调p H 2.80)、槲皮素为无水甲醇-0.4%磷酸溶液(55∶45,V/V),等梯度洗脱,白藜芦醇为水和甲醇,二元线性梯度洗脱;检测波长分别为:254 nm、360 nm和306 nm;流速:0.8 m L/min、1.0 m L/min、0.8 m L/min。通过该方法测得芦丁、槲皮素及白藜芦醇的平均回收率分别为:98%、97%、98%。     

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.