傣族药用植物盆架树中的三萜

从傣族药用植物盆架树(Winchia calophylla A. DC.)茎皮的石油醚可溶部分分离到9个化合物,经现代波谱技术证明,其中之一为新化合物,命名为盆架酸(winchic acid).另8个已知化合物分别为羽扇豆烯酮、乙酸羽扇豆酯、桦木酸、乙酸-α-香树醇酯、乌索酸、ptiloepoxide、β-香树醇和cycloeucalenol.     

药用植物盆架树中的缩醛

夹竹桃科药用植物盆架树(Winchiacalophylla)茎皮的乙醇提取物,经石油醚脱脂后用盐酸和氨水处理,再用石油醚、氯仿和正丁醇萃取。从正丁醇部分分离出6个化合物,其中3个为新成分,分别命名为盆架丁基缩醛、异盆架丁基缩醛和盆架乙基缩醛;另3个已知化合物依次为丁基-β-D-呋喃葡萄糖甙、丁基-β-D-吡喃葡萄糖甙和丁基-α-D-吡喃葡萄糖甙。他们可能是人工产物。     

药用植物盆架树中的缩醛

夹竹桃科药用植物盆架树( Winchia calophylla) 茎皮的乙醇提取物, 经石油醚脱脂后用盐酸和氨水处理, 再用石油醚、氯仿和正丁醇萃取。从正丁醇部分分离出6 个化合物, 其中3 个为新成分, 分别命名为盆架丁基缩醛、异盆架丁基缩醛和盆架乙基缩醛; 另3 个已知化合物依次为丁基-β-D-呋喃葡萄糖甙、丁基-β-D-吡喃葡萄糖甙和丁基-α-D-吡喃葡萄糖甙。他们可能是人工产物。     

印度蛇菰的三萜成分

从我国民间药和植物印度蛇训分离得到７个化合物,经鉴定为：棕榈酰β－香树酯,棕榈酰羽扁豆烯醇酯,乙酰β－香树酯,乙酰羽酰羽扁豆烯醇酯,β－香树脂酮,羽扇豆烯酮及棕酸。运用光谱和化学的方法对它们的结构进行解析。     

药用植物盆架树中的马钱子苷及其衍生物

从药用植物盆架树(Winchia calophylla A．Dc．)的茎皮中分离得到4个环烯醚萜苷类化合物,其结构经现代波谱技术鉴定为马钱子苷、7-O-甲酰基马钱子苷、6 '-O-甲酰基马钱子苷和6',7-O-二甲酰基马钱子苷,其中后3个化合物为新化合物。     

铜锤玉带草三萜酯化学成分分析

脂肪酸广泛分布于自然界各种生物之间,但是脂肪酸与多萜类化合物,尤其是三萜类化合物,结合形成多萜酯,极为少见。我们自云南民间中草药铜锤玉带草中分离得到3个高级脂肪酸三萜酯;其中2个经鉴定为:棕榈酸-β-香树酯,珠光脂酸-β-香树酯,并运用化学和光谱学的方法对他们的化学结构进行了解析。     

盆架树中单萜吲哚生物碱成分的分离与结构鉴定

本文对夹竹桃科盆架树属盆架树(Winchia calophylla A.DC.)小枝的化学成分进行了研究,从其甲醇提取物中分离得到4个单萜吲哚生物碱。采用波谱技术并结合文献分别鉴定为echitamidine、17-O-acetyl-Nb-demethylechitamine、Nb-demethylechitamine、Nb-demethylechitamine N-oxide。     

大果大戟的化学成分

从大果大戟的根部首次分离得到11个化合物。利用波谱方法鉴定为β-香树素(1),β-香树素乙酸酯(2),3β-乙酰化羽扇豆烯醇(3),baccatin(4),2个caffeic mters(5a,5b),棕榈酸-1-甘油酯(6),棕榈酸(7),东莨菪内酯(8),β-谷甾醇(9)和胡萝卜甙(10)。其中5a,5b是第一次在大戟属中得到;并对5a,5b的碳谱和氢谱数据进行了全归属。     

苦丁茶冬青化学成分的结构研究

从苦丁茶冬青叶中分得4个新的三萜酯,及6个已知三萜,其化学结构分别由NMR,MS,IR等方法获得。这4个新三萜酯是:α-香树醇-3β-棕榈酸酯,11-羰基-α-香树醇-β-棕榈酸酯,3β-羟基-羽扇-20(29)-烯-24羰酸甲酯和羽扇-20(29)-烯-24-羰酸甲酯-3β-棕榈酸酯。     

大苞蛇根草化学成分的研究

利用柱色谱技术进行分离纯化,通过理化性质及波谱方法对大苞蛇根草单体化合物进行了结构鉴定.从中共得到6个单体化合物,分别为豆甾醇(1)、β-谷甾醇(2)、胡萝卜甙(3)、3β-乙酸基-20-羽扇豆烷(4)、无羁萜(5)、铁力木酸(6).均为首次从该植物中得到.     

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.