大黄属3种大黄植物不同部分蒽醌含量的测定与比较

采用C18反相柱高效液相色谱方法分离、外标法定量对大黄属掌叶组唐古特大黄、波叶组波叶大黄、穗序组穗序大黄的根（及根茎）、叶片、叶柄、主茎四部分的芦荟大黄素、大黄酸、大黄素、大黄酚4种游离和结合蒽醌的含量进行了测定和比较。结果表明：唐古特大黄中,叶片中的游离蒽醌含量高于其它部分,游离蒽醌总量地上部分远高于地下部分;结合蒽醌则根中最高,蒽醌总量地下部分远高于地上部分。波叶大黄和穗序大黄中,游离和结合蒽醌均为根中最高,穗序大黄蒽醌总量地下部分远高于地上部分,而波叶大黄中,游离蒽醌总量地上部分高于地下部分,结合蒽醌总量地上部分与地下部分相差不大,地上部分略高于地下部分。     

大黄药材、浸膏及其清胃颗粒剂质量的RP—HPLC分析

建立适合大黄药材、大黄浸膏及清胃颗粒剂过程分析与质量控制的反相高效液相色谱方法.采用YWG-ODS 10μm(200×4.0mm ID)色谱柱,流动相组成为甲醇-水-高氯酸(75250.1V/V),检测波长254nm,流速1.0ml/min,柱温控制20℃.以芦荟大黄素、大黄素、大黄酸、大黄酚和大黄素甲醚的峰面积作为定量信息,标准曲线外标法测定样品含量.结果表明,清胃颗粒剂中五种游离蒽醌成分的平均加样回收率分别为芦荟大黄素95.61%(RSD3.05%)、大黄素98.03%(RSD2.77%)、大黄酸100.1%(RSD2.21%)、大黄酚97.49%(RSD3.64%)和大黄素甲醚96.79%(RSD4.12%).本法操作简便、检测灵敏,适合于大黄药材、大黄浸膏及清胃颗粒剂过程分析与质量控制.     

青海栽培和野生唐古特大黄蒽醌类成分的HPLC对比分析

采用HPLC法测定青海栽培唐古特大黄中的5种蒽醌含量,并和野生唐古特大黄药材进行了比较.结果表明,二、三、四年龄栽培唐古特大黄中芦荟大黄素、大黄酸、大黄素、大黄酚、大黄素甲醚5种蒽醌总量分别为1.21%,2.01%,1.62%,其中三、四年龄栽培唐古特大黄已达到<药典>规定的药用标准;野生大黄的总蒽醌含量远高于栽培大黄为3.64%.     

栽培唐古特大黄蒽醌含量的季节动态变化

采用高效液相色谱法,测定3、4年生生长季节内不同月份的青海栽培唐古特大黄中芦荟大黄素、大黄酸、大黄素、大黄酚、大黄素甲醚等5种蒽醌类化合物的含量。结果表明,3年、4年生大黄总蒽醌含量在5~6月份生长初期增加,并于6月初达到最大值,6~9月份生长旺盛期间明显降低,10月份又略有回升;3年和4年生大黄总蒽醌含量分别在0.8%~2.5%和1.3%~2.1%范围内波动。     

高速逆流色谱对大黄蒽醌类成分的分离研究

利用高速逆流色谱对大黄中的5个蒽醌活性成分进行了分离,当两相溶剂系统的组成是石油醚∶乙酸乙酯∶甲醇∶水=8∶2∶8∶1时,分离出大黄素;当两相溶剂比为3∶4∶3∶2时,分离出大黄酸和芦荟大黄素;当溶剂比为12∶2∶12∶1时,分离出大黄酚和大黄素甲醚;经高压液相色谱检测大黄素、大黄酸和芦荟大黄素、大黄酚和大黄素甲醚的含量分别为98.81%9、9.15%、98.51%9、8.89%和98.16%。     

切片厚度和烘干温度对唐古特大黄蒽醌含量影响的研究

采用HPLC-DAD法测定了不同切片厚度在不同烘干温度下唐古特大黄中芦荟大黄素、大黄酸、大黄素、大黄素甲醚、大黄酚的含量,探究切片厚度和烘干温度对唐古特大黄药材质量的影响。色谱柱采用的是Agilent Eclipse plus C18(4. 6×250 mm,5μm);流动相A相为色谱级别甲醇,B相为0. 1%冰乙酸溶液;柱温25℃;检测波长254 nm。结果表明:75℃烘干,切片厚度以0. 4～2 cm或6～7 cm; 25、50℃时烘干,切片0. 4～3 cm或6～8 cm,药材总蒽醌含量较高,其他厚度含量较低,芦荟大黄素、大黄酸、大黄素、大黄素甲醚、大黄酚的含量也符合上述规律。结论唐古特大黄产地初加工时,75℃烘干,切片厚度以0. 4～2 cm或6～7 cm为宜; 25和50℃时烘干,切片0. 4～3 cm或6～8cm为宜,从而保证唐古特大黄药材的质量。     

大黄酚和大黄素甲醚的制备性分离

经系统分离得到大黄酚和大黄素甲醚的混合物后,取该混合物约1g,用少量的氯仿溶解,加入少量的层析用硅胶（100～200目）拌匀,减压使氯仿蒸干。将吸附有大黄酚和大黄素甲醚的硅胶装在已装好的硅胶层析柱的上端,然后进行洗脱。通过实验,得到了最佳分离大黄酚和大黄素甲醚的条件：硅胶与混合物的质量比=150：1;层析柱长与直径的比=23：1;洗脱剂比例：石油醚（60～90℃）：乙酸乙酯（V/V）=17：1;减压淋洗。     

毛脉酸模内生真菌蒽醌类次生代谢产物的筛选及含量分析

本文通过对毛脉酸模内生真菌的发酵培养得到其次生代谢产物,采用HPLC法对内生真菌中蒽醌类成分进行筛选。以大黄素、大黄酸、大黄酚、大黄素甲醚、芦荟大黄素五种蒽醌类成分为参照,筛选出3株真菌含大黄素、3株真菌含大黄酸、5株真菌含芦荟大黄素,其中含量最高为683μg/g、最低为8μg/g。将各菌株所含成分与各菌株分离部位的相应成分进行比较,相对宿主植物而言各菌株均有较高的含量。本实验分析方法准确、快捷,适用于毛脉酸模内生真菌的代谢产物研究。     

粗柄独尾草不同器官蒽醌类成分的消长规律

采用高效液相色谱法对沙生类短命植物粗柄独尾草苗期、营养生长期、初花期、盛花期、果期各器官中大黄素、大黄酚、大黄酸、芦荟大黄素含量的消长规律进行了研究。结果表明:叶中,芦荟大黄素的含量在苗期和初花期都较高,在盛花期时最低;大黄酸的含量在苗期最高,盛花期时最低;大黄素的含量在苗期达到最高,初花期和盛花期最低;大黄酚的含量也以苗期最高,盛花期和果期最低。且在初花期时,4种蒽醌类物质含量均呈现明显的叶先端>叶中部>叶基部的空间差异性。根中,芦荟大黄素的含量在苗期和营养生长期较高,而以盛花期和果期较低;大黄酸的含量在果期最高,其余时期差异不显著;大黄素的含量以苗期和初花期较高;大黄酚的含量在果期达最高,而盛花期时最低。同时期的根叶蒽醌含量相比,叶中的芦荟大黄素要高于根,而根中大黄酚含量要高于叶。同时期各器官蒽醌总量相比:叶>根>花>花葶。故若选取粗柄独尾草作为蒽醌类药材利用,建议最佳采集方式为采集初花期的叶先端部分。     

中药抗厌氧菌的系列研究：Ⅲ.大黄抗厌氧菌的实验研究

本研究进一步用大黄水煎液,大黄醇提物和大黄蒽醌衍生物(芦荟大黄素、大黄酸和大黄素),对临床分离的100株厌氧菌进行MIC测定,并对部分菌株进行MBC测定和亚抑菌浓度(Sub-MIC)下细菌形态观察。结果表明,大黄水煎液在1600μg/ml浓度时能抑制74％厌氧菌生长,大黄醇提物的MIC约为水煎液的1/15。三种蒽醌衍生物在8μg/ml时能抑制76～91％厌氧菌生长,这与国际公认的抗厌氧菌药甲硝唑相近。对部分菌株的MBC测定表明,大黄的MBC要大于MIC几倍以上,说明大黄抗厌氧菌主要是抑菌不是杀菌。从Sub-MIC下厌氧菌形态改变提示,大黄主要是抑制细胞壁的合成。     

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.