白木香树干中的黄酮类成分

从白木香[Aquilaria smensis(Lour.)Gilg]树干的乙醇提取物中分离得到5个黄酮类化合物,经波谱分析,分别鉴定为:洋芹素-7,4'-二甲醚(1)、5-羟基-7,3',4'-三甲氧基黄酮(2)、木犀草素-7,4'-二甲醚p)、芫花素(4)和4',5-二羟基-3',7-二甲氧基黄酮(5).以上化合物均为首次从该种植物树干中分离得到.     

芙蓉菊中黄酮类化学成分的研究

从菊科芙蓉菊属植物芙蓉菊的全草中分离得到六个黄酮类化合物,经光谱分析鉴定为:5,7-二羟基-3',4',5'-三甲氧基黄酮(1),粗毛豚草素(2),3',4'-二甲氧基-5',5,7,-三羟基黄酮(3),万寿菊黄索-3,6,7-三甲醚(4),石杉黄素(5),槲皮素-7-O-β-D.葡萄糖苷(6).这些黄酮类化合物皆为首次从该属植物中分离得到.     

益智茎叶中黄酮类化学成分研究

对益智茎叶中黄酮类化学成分进行研究,采用多种色谱方法进行分离纯化,运用多种谱学方法并结合理化性质对分离得到的化合物进行结构鉴定。结果从益智茎叶95%乙醇提取物中共分离得到11个黄酮类化合物,其中包括8个黄酮类化合物,分别鉴定为:良姜素(izalpinin)(1)、杨芽黄素(tectochrysin)(2)、白杨素(chrysin)(3)、芹菜素(apigenin)(4)、刺槐素(acacetin)(5)、5-羟基-4',7-二甲氧黄酮(5-hydroxy-4',7-dimethoxyflavone)(6)、山奈酚-4'-O-甲醚(kaempferol-4'-O-methylether)(7)、5,7,4'-三甲氧基黄酮(5,7,4'-trimethoxyflavone)(8)和3个二氢黄酮类化合物,分别鉴定为:乔松素(pinocembrin)(9)、球松素(pinostrobin)(10)和二氢山萘酚(dihydrokaempferol)(11)。所有化合物均为首次从该植物茎叶中分离得到,其中化合物6、8和10为首次从该属植物中分离得到。     

单叶蔓荆子黄酮类化学成分研究

采用MCI-Gel及硅胶等柱色谱法对云南西双版纳单叶蔓荆子的甲醇提取物的乙酸乙酯部分进行分离纯化,得到5个黄酮类似物,根据其理化性质,结合光谱技术(MS,NMR等)鉴定为紫花牡荆素(1)、3',5-二羟基-3,4',7-三甲氧基黄酮(2)、4',5-二羟基-3,6,7-三甲氧基黄酮(3)、牡荆葡基黄酮(4)和山奈酚-3-O-葡萄糖苷(5),化合物2～5为首次从该植物中分离得到.进行了抗羟基自由基氧化和抑菌活性的初步筛选实验,首次报道了化合物2、3的清除羟基自由基活性.     

广藿香大极性化学成分的研究

从广藿香(Pogostemon cablin (Blance)Benth.)地上部分乙醇提取物的正丁醇萃取部位分离得到13个化合物.通过光谱和波谱分析,分别鉴定为:芹菜素(1)、3,5,4'-三羟基-7-甲氧基黄酮(2)、3,5-二羟基_4',7-二甲氧基黄酮(3)、Apigenin 7-galacturonide(4)、Apigenin 7-(O-methylghacuronide)(5),Luteolin 7-O-(6-O-methyl-β-D-glucuronopyranoside)(6),4',5-二羟基-3',7-二甲氧基二氢黄酮(7)、Quercetha-7-β-D-ghcoside(8),3,23-Dihydroxy-12-oleanen-28-oic acid(9)、Syringaresinol-β-D-glucoside(10),毛蕊花糖苷(11)、列当苷(12)、紫葳新苷(13),化合物2～13均为首次从该植物中分离得到.     

香樟叶化学成分的研究

采用硅胶色谱柱层析、聚酰胺色谱柱层析、制备薄层色谱及其它分离手段从香樟叶(Cinnamomum camphora Leaves)70%乙醇提取中分离得到9个化合物,根据化合物理化性质和波谱数据分别鉴定为:邻苯二甲酸二丁酯(1)、l-细辛脂素(2)、(8R,8'R)-3,3',4,4'-四甲氧基-9-氧代-8-8',9-O-9'-木脂素(3)、槲皮素-3-Ο-β-D-葡萄糖苷(4)、山奈酚-3-O-β-芸香糖苷(5)、山柰酚-3-O-α-L-吡喃鼠李糖苷(6)、槲皮素3-Ο-α-L-鼠李糖苷(7)、芦丁(8)、异鼠李素-3-O-β-芸香糖苷(9)。其中化合物1,2,6和9为首次从该种植物叶中分离得到。     

味噌异黄酮类化学成分

对味噌中异黄酮类化学成分进行了研究。通过硅胶柱色谱、Sephadex LH-20凝胶柱色谱、反相C18硅胶柱色谱以及制备HPLC等方法,对味噌正丁醇萃取部位进行分离纯化,根据化合物的理化性质和波谱数据(1H NMR、13C NMR、HMBC、MS)鉴定单体化合物的化学结构。总共分离得到6个异黄酮类化合物(图1),分别鉴定为:染料木素(1)、大豆素(2)、黄豆黄素(3)、4',5,7,8-四羟基异黄酮(4)、4',7,8-三羟基异黄酮(5)、4',7,8-三羟基-6-甲氧基异黄酮(6)。以上化合物均为首次从味噌中分离得到。     

艾纳香地上部分化学成分及其抗氧化与酪氨酸酶抑制活性研究

本文对艾纳香(Blumea balsamifera DC.)中的化学成分及其抗氧化与酪氨酸酶抑制活性进行了研究.利用各种色谱手段和波谱学方法,从艾纳香地上部分分离得到18个化合物,分别鉴定为:7,3',4'-三甲基槲皮素(1)、4',5-二羟基-3',7-二甲氧基黄酮(2)、木犀草素-7-甲醚(3)、鼠李素(4)、(2...     

大苞鞘石斛化学成分研究

通过硅胶柱层析、纯化,从大苞鞘石斛中分离得到5个化合物,利用理化性质和波谱分析分别鉴定为钩状石斛素(1)、愉悦石斛素(2)、4',5,7-三羟基-3′,5′-二甲氧基黄烷酮(3)、β-胡萝卜苷(4)和β-谷甾醇(5).所有化合物均为首次从大苞鞘石斛中分离得到.     

无梗五加根中苯丙素类化合物的研究

从无梗五加(Acanthoparax sessiliflorus( Rupr.et Maxim.)Seem.)根70％乙醇提取物的乙酸乙酯层中提取分离得到8个苯丙素类化合物.经理化和波谱分析鉴定为(+)-表芝麻脂素(1)、(-)-芝麻脂素(2)、赛菊芋黄素(3)、洒维宁(4)、咖啡酸甲酯(5)、对羟基桂皮酸(6)、(-)-丁香脂素(7)、(+)-松脂索(8).化合物8是首次从五加科植物中分离得到,化合物1和5是首次从五加属植物中分离得到,化合物3、6和7是首次从该植物中分离得到.     

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.