龙胆草地上部分的化学成分

为研究龙胆草（Gentiana scabra Bunge）地上部分的化学成分,利用硅胶柱色谱对其乙醇提取物进行分离纯化,根据理化性质和波谱方法鉴定了化合物的结构。分离得到β-香树脂醇（1）、β-谷甾醇（2）、β-香树脂醇乙酸酯（3）、乌苏醇（4）、齐墩果酸（5）、6-去甲氧基-7-甲基茵陈色原酮（6）。其中化合物6为首次从龙胆科植物中分离得到的具有2-苯氧基色原酮骨架的天然酚类成分,本文对其1D和2DNMR谱的特征及EI质谱主要碎片的可能裂解方式进行了讨论,利用单晶X-射线衍射方法对其晶体结构进行了分析,为该类天然产物的结构表征提供了依据。     

榕树须活性部位的成分研究

采用硅胶柱层析色谱和重结晶方法对榕树须95%乙醇提取物进行分离,得到8化合物,通过理化性质和波谱技术分别鉴定为:α-香树脂醇乙酸酯(1),羽扇豆醇乙酸酯(2),木栓酮(3),木栓醇(4),正三十五烷醇(5),白桦酯酸(6),β-谷甾醇(7)和豆甾-4-烯-6β-羟基-3-酮(8)。除化合物6外,其余化合物均为首次从该植物中分离得到。     

海南染木树茎的化学成分研究(Ⅰ)北大核心CSCD

研究海南染木树茎的化学成分,采用硅胶、Sehadex LH-20、ODS、HPLC等色谱技术对海南染木树茎乙醇提取物的乙酸乙酯部位进行分离和纯化,结合光谱数据和理化性质鉴定化合物的结构,分别为：4-甲基苯并喹啉-5,10-二酮（1）、白兰花碱（2）、鹅掌楸碱（3）、吲哚-3-甲醛（4）、羽扇豆醇（5）、霍烷-3,30-二醇（6）、熊果酸（7）、白桦酯酸（8）、30-羟基羽扇豆醇（9）、豆甾醇（10）、3β-乙酰基齐墩果醛（11）。其中,化合物4、7为首次从染木树属植物中分离得到,5、6、8、9-11为首次从该植物中分离得到。首次对化合物2的碳谱数据进行了归属。     

大叶盘果菊化学成分的研究

采用乙醇提取,硅胶柱层析分离和波谱方法鉴定结构,从大叶盘果菊(Prenanthes macrophylla Franch)中初步分离鉴定出8个化合物:木栓酮(friedelin,1)、木栓醇(friedelanol,2)、α-香树脂醇(α-amyrin,3)、α-香树脂醇乙酸脂(α-amyrin acetate,4)、β-香树脂醇乙酸酯(β-amyrin acetate,5)、蒲公英甾醇乙酸酯(taraxasteryl acetate,6)、β-谷甾醇(β-sitosterol,7)、二十八烷酸(octacosanoic acid,8),这些化合物均为首次从该植物中分离得到。     

白粉藤的木脂素和三萜成分

从白粉藤（Cissus repens Lank）地上部分分离得到5个木脂素和8个三萜,其中一个木脂素是新化合物,它的结构通过波谱分析和碱水解的方法鉴定为：（＋）-异落叶松树脂醇-9′-（2-对-香豆酰）-O-β-D-吡喃木糖苷（1）。其余化合物分别是：（＋）-异落叶松树脂醇-9′-O-β-D-吡喃木糖苷（2）,（＋）-Lyoniside（3）,（—）-开环异落叶松树脂醇-9-O-β-D-吡喃木糖苷（4）,（7′R,8′S）-4′-hydroxy-3′,5-dimethoxy-7,8′-dihydrobenzofuran-1-propanolneolignan-9′-O-β-D-xylopyranoside（5）,木栓酮（6）,表木栓醇（7）,蒲公英赛醇乙酸酯（8）,熊果酸（9）,2α-羟基乌索酸（10）,积雪草酸（11）,Niga-ichigoside F1（12）,羽扇豆醇（13）。这些化合物都是首次从该植物中分离得到。     

构树皮中三萜类化学成分

对构树皮的化学成分进行进一步研究,通过反复硅胶柱层析从构树皮乙醇提取物的石油醚萃取部位中分离得到六个三萜成分,利用波谱技术及理化性质鉴定其化学结构分别为3β-乙酰氧基-甘遂-7-烯-24S,25二醇(1),3β-乙酰氧基-7,23-甘遂二烯-25-醇(2),羽扇豆醇(3),α-香树脂醇乙酸酯(4),3β,25-二羟基-7,23-甘遂二烯(5)和β-香树脂醇(6)。其中化合物1为新的甘遂烷型三萜,化合物2～5为首次从该植物中分离得到。     

蓝桉果实中的脂溶性成分

从蓝桉(Eucalyptus globulusLabill.)果实乙醇提取物的石油醚部位分离鉴定出6个化合物,通过理化和波谱分析结构鉴定为:5-羟基-4′,7-二甲氧基-6-甲基黄酮(1)、blumenol A(2)、蓝桉醇(3)、绿花白千层醇(4)、β-谷甾醇(5)、二十二烷酸(6),其中化合物1~4和化合物6系首次从该植物中分离得到,化合物1和2首次从桉属植物中分离得到.     

米碎花茎枝的化学成分研究

为探讨山茶科（Theaceae）柃木属植物米碎花（Eurya chinensis R. Brown）茎枝的化学成分,从米碎花茎枝95%乙醇提取物中分离得到8个化合物,根据现代波谱技术和文献对照,鉴定其结构分别为：高根二醇（1）、白桦酸（2）、木栓酮（3）、羽扇豆醇（4）、β-谷甾醇（5）、豆甾醇（6）、邻羟基苯甲醛（7）、正二十九烷醇（8）。所有化合物均为首次从该植物中分离得到。     

绿玉树化学成分研究北大核心CSCD

采用正反相硅胶、Sephadex LH-20和HPLC等色谱手段对绿玉树Euphorbia tirucalli化学成分进行分离纯化,从绿玉树地上部分70%丙酮提取物中分离得到12个化合物。利用MS、1H NMR和13C NMR等现代波谱技术确定化合物结构为4α-去氧-巴豆醇-13-乙酸酯（1）、对映-3β,13S-二羟基-16-烯-14-阿替森酮（2）、羊毛甾醇（3）、3-表-粘霉烯醇（4）、齐墩果烷-9（11）,12-二烯-3-酮（5）、β-香树烯酮（6）、齐墩果烷-18-烯-3-酮（7）、无羁萜（8）、4-豆甾烯-3-酮（9）、β-谷甾醇（10）、山奈酚-3-O-α-L-鼠李糖苷（11）和东莨菪内酯（12）。其中,化合物1、2、5-7、9和12为首次从该植物中分离得到。     

兖州卷柏化学成分及体外抗菌活性研究

本文研究兖州卷柏Selaginella involvens Spring.的化学成分及体外抗菌活性.运用反复色谱层析进行纯化分离得到7个化合物,经波谱解析结合理化鉴定确定化合物结构为:正十六烷酸(1),正十八烷酸(2),β-谷甾醇(3),豆甾醇(4),穗花杉双黄酮(5),β-D-glucopyranoside,(3β)-cholest-5-en-3yl(6),β-香树脂醇(7).化合物1～7均首次从该植物中分离得到,6和7首次从该属植物中分离得到.此外研究了化合物5、6和7的体外抗菌活性.化合物5、6和7可能为兖州卷柏抗肺炎病菌的主要物质基础.     

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.