尖叶胡枝子黄酮类化学成分的研究

采用硅胶、凝胶和聚酰胺等柱层析及HPLC等方法对尖叶胡枝子[Lespedeza hedysaroides (Pall.) Kitag.]70%乙醇提取物中的黄酮类化学成分进行研究,共分离得到8个化合物,通过光谱和波谱分析,分别鉴定为荭草素(1)、牡荆苷(2)、异荭草素(3)、异牡荆苷(4)、槲皮素-3-O-β-D-葡萄糖苷(5)、木犀草素-7-O-葡萄糖苷(6)、6-xylopyranosylluteolin(7)、异杨梅树皮苷(8),其中化合物5～8为首次从尖叶胡枝子中分离得到.研究结果表明:碳苷黄酮(化合物1～4)是尖叶胡枝子黄酮类的主要成分,具有较好的药理活性,作为一种药用植物资源,尖叶胡枝子具有广阔的开发利用前景.     

蓝花侧金盏化学成分的研究

从藏药蓝花侧金盏的乙醇溶液中分离得到8个化合物,通过波谱学方法分别鉴定为三十一烷醇(1)、对甲酰基肉桂酸(2)、芹菜素(3)、木犀草素(4)、荭草苷(5)、木犀草素-7-O-β-D-葡萄糖苷(6)、异荭草苷(7)及侧金盏醇(8)。化合物1、2、4、6、7均首次从该种植物中分离得到。     

大叶紫珠苯丙素类衍生物研究

采用硅胶、Sephadex LH-20、ODS柱层析等色谱技术,从大叶紫珠70%乙醇提取物的乙酸乙酯萃取部位分离得到10个苯丙素类衍生物。通过波谱分析并与文献数据对照方法,将其分别鉴定为蛇菰宁(1)、(7R,8S)-脱氢松柏醇-8,5'-脱氢松柏醛-9-O-β-D-吡喃葡萄糖苷(2)、连翘苷B(3)、alyssonoside(4)、天人草甙B(5)、阿克苷(6)、马蒂罗苷(7)、异阿克苷(8)、车前草甙C(9)和异马蒂罗苷(10)。其中,化合物3~10均为首次从该植物中分离得到。     

孑遗植物桫椤叶化学成分的研究

采用甲醇浸泡提取,依次用石油醚、乙酸乙酯和正丁醇萃取,通过反复硅胶柱色谱分离的方法研究桫椤叶的化学成分,得到7个化合物,根据光谱数据和理化性质鉴定分别为牡荆素(vitexin)(1)、异荭草素(isorientin)(2)、芹菜素(apigenin)(3)、木犀草素(luteolin)(4)、diploterol(5)、胡萝卜苷(daucosterol)(6)、β-谷甾醇(β-sitosterol)(7).7个化合物均为首次在桫椤中分离获得.     

蜡菊花的化学成分研究

从菊科植物蜡菊(Helichrysum bracteatumVent)花的乙醇提取物中分离出11个化合物,经波谱分析鉴定为subscandenin(1),江户樱花苷(2),圣草素5-O-β-D-葡萄吡喃糖苷(3),pyracanthoside(4),槲皮素(5),木犀草素(6),柯伊利素(7),异荭草素(8),咖啡酸(9),piperitol(10),4-hydroxymethyl-1-methoxycarbonylazulene(11)。这些化合物均为首次从该植物中分离得到。     

小叶三点金的黄酮类成分研究

从小叶三点金(Desmodium microphyllum)乙醇溶液中分离得到9个黄酮类化合物,通过波谱学方法分别鉴定为()-表儿茶素(1)、genistein-4′-O-β-glucoside(2)、异荭草苷(isoorientin,3)、荭草苷(orientin,4)、木犀草素(luteotin,5)、异日本獐牙菜素(isoswertiajaponin,6)、luteoayamenin(7)、木犀草素-7-O-β-D-葡萄糖苷(luteolin-7-galactoside,8)、木犀草素-7-O-鼠李糖苷(luteolin-7-rhamnoside,9)。所有化合物均为首次在该植物中分离得到。     

铁甲草化学成分的初步研究

采用硅胶柱色谱分离方法,研究了铁甲草(Cassia mimosoides Linn.)乙醇提取物中的化学成分.从铁甲草中分离得到8个化合物:大黄素(1)、木犀草素(2)、间苯二酚(3)、齐墩果酸(4)、(R)-鹰爪三醇(5)、α-L-鼠李糖(6)、β-谷甾醇(7)和胡萝卜苷(8).除化合物1以外,其余均是首次从铁甲草中分离得到,其中化合物5为首次在该科植物中发现.     

裸花紫珠的化学成分

从裸花紫珠(Callicarpa nudiflora Hook.ex Arn.)地上部分的乙醇提取物中分离得到了7个化合物,经波谱分析确定其结构分别为:木犀草苷(1),木犀草素-3'-O-β-D-吡喃葡萄糖苷(2),木犀草素-4'-O-β-D-吡喃葡萄糖苷(3),2α,3α,19α-三羟基-乌索-12-烯-28-酸(4),乌索酸(5),2α-羟基-乌索酸(6)和齐墩果酸(7)。其中化合物2-7为首次从该植物中分离得到。     

显脉獐牙菜化学成分研究Ⅱ

对显脉獐牙菜(Swertia nervosa)的化学成分研究。采用系统溶剂提取,常规硅胶柱色谱和薄层色谱进行分离纯化,根据化合物的物理、化学性质,UV、IR、MS、1H NMR、13C NMR等波谱鉴定其结构。从显脉獐牙菜中分离得到10个化合物,分别鉴定为1,5,8-三羟基-3-甲氧基酮(1)、1,3,8-三羟基-5-甲氧基酮(2)、5,7,3',4'-四羟基黄酮(3)、3,5,7,3',4'-四羟基黄酮(4)、2-C-β-D-吡喃葡萄糖-1,3,6,7-四羟基酮(5)、獐牙菜苦苷(6)、当药苦酯苷(7)、羟基当药苦酯苷(8)、齐墩果酸(9)、胡萝卜苷(10),化合物3~5、7、8和10为首次从显脉獐牙菜中分离得到。     

秃叶黄皮树叶子的化学成分研究(英文)

从秃叶黄皮树叶子(Phellodendron chinensevar.glabriusculumSchneid)分离到7个化合物,经波谱解析鉴定为6-O-乙酰基黄柏苷(1),6-O-乙酰基二氢黄柏苷(2),(2R)-4′,5-二羟基-7-O-β-D-吡喃葡萄糖基-8-异戊烯基-二氢黄酮(3),黄柏苷(4),2-O-β-D-吡喃葡萄糖基-6-羟基-苯甲酸苄酯(5),柑橘素C(6),3-羰基齐墩果烷(7),其中化合物1～3,5～7为首次从秃叶黄皮树叶子中分离得到。     

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.