金叶子的化学成分

从金叶子(Craibiodendron yunnanenseW.W.Smith)叶部分的70%丙酮提取液中共分离得15个化合物,分别鉴定为:asebotoxin-III(1),grayanotoxin-XVIII(2),leucothol A(3),proA-4(4),槲皮素-3-O-β-半乳吡喃糖苷(5),槲皮素-3-O-α-阿拉伯呋喃糖苷(6),槲皮素-3-O-α-鼠李吡喃糖苷(7),山奈酚-3-O-α-鼠李吡喃糖苷(8),2,4-bis(4-hydroxyphengl)-1,3-cyclobutane dicarboxglic aicd(9),(Z)-对羟基桂皮酸(10),(E)-对羟基桂皮酸(11),香草酸(12),2α,3β-dihydroxyurs-5,12-dien-28-oic acid(13),2α,3β,23-trihydroxyurs-12-en-28-oic acid(14)和β-谷甾醇(15)。化合物1~4,8~14为首次从该种植物中得到。其中木藜芦烷类二萜asebotoxin-III(1)为主成分之一,我们推测化合物1和其余两个木藜芦烷类二萜grayanotox-in-XVIII(2),leucothol A(3)为金叶子的活性成分,可能与该植物具有活络止痛的药效有密切的关系。     

金叶子属分类、分布与演化趋势的研究

<正> 金叶子属(Craibiodendron W.W.Shmith)是杜鹃花科中的一个小属,含6种,分布于亚洲东南部,其现代分布中心在我国的云南南部。在杜鹃花科中,金叶子属与米饭花属(Lyonia Nutt.)、马醉木属(Pieris D.Don)有密切的关系。作者在完成(中国植物志)、(云南植物志)、(西藏植物志)该属工作过程中,查阅了近500号本属植物标本,并对分布于云南境内的本属植物进行了野外考察,认为有必要对本属的分类、分布及演化趋势进行讨论。现将研究心得发表如下。     

金叶子中抑制膜结合型PGE2合酶-1表达活性物质的分离与鉴定

在从天然产物筛选抗炎物质的过程中,应用有机溶媒萃取、浓缩及层析分离纯化后,从金叶子中得到三个化合物:槲皮素(1)、番石榴苷(2)、栎素(3).化合物2为首次从此植物中分离鉴定,化合物1显示了强烈的抑制mPGES-1基因表达的活性,其IC50值为35.40μg/mL.     

马蹄荷化学成分研究

从马蹄荷(Exbucklandia populnea R.W.Br.)茎皮中首次分离得到6个化合物,通过波谱分析鉴定为β-谷甾醇(I)、胡萝卜甙(Ⅱ)、樱桃甙(Ⅲ)、芒花甙(Ⅳ)、圣草酚(V)和白藜芦醇(Ⅵ)。     

长果雪胆的两种皂甙

长果雪胆(Hemsleya dolichocarpa W. J. Chang)为葫芦科(Cucurbitaceae)雪胆属植物。最近我们从其块根中分离、鉴定了竹节参甙-Ⅴ和竹节参甙-Ⅳa甲酯。两种成分均为首次由雪胆属植物中获得。 竹节参甙-Ⅴ为白色粉末,Liebermann-Burchard反应和泡沫试验为阳性,薄层板上     

裂冠牛奶菜的化学成分

从裂冠牛奶菜(Marsdenia incisa P. T. Li et Y. H. Li)的粗甙酸水解产物中分离得到2个已知的C_(21)甾体甙元——肉珊瑚甙元(sarcostin, Ⅰ),青羊参甙元(qingyangshengenin,Ⅱ),和一个新的C_(21)甾体甙元,命名为裂冠牛奶菜甙元A(incisagenin-A,Ⅱ)经光谱分析和化学反应,证明(Ⅲ)的结构为12-β-氧-顺芷酰去酰基萝藦甙元。     

大理白前的化学成分

从大理白前(Cynanchum forrestii Schltr.)中分离得到2个C_(21)甾体甙,其中一个新甙,命名为大理白前甙A(cynaforroside—A,Ⅰ)。经光谱分析和化学反应,证明(Ⅰ)的结构为芫花白前甙元C 3-氧-α-L-加拿大麻吡喃基-(1→4)-β-L-加拿大麻吡喃基-(1→4)-β-D-夹竹桃吡喃甙(glaucogenin C 3-O-α-L-cymaropyranosyl-(1→4)-β-L-cymaropyranosyl-(1→4)-β-D-oleandropyranoside)     

苦绳甙甲的结构

从苦绳(Dregea sinensis var. corrugata)的根茎中分得一个新的C_(21)-甾体甙成分,命名为苦绳甙甲(dregeoside A)。经光谱分析和化学反应证明,其结构为:苦绳甙元甲3-O-3-O-甲基-6-去氧-β-D-阿洛吡喃糖(1→4)-β-D-夹竹桃吡喃糖(1→4)-β-D-磁麻吡喃糖,(1→4)-β-D-磁麻吡喃糖甙(drevogenin A 3-O-3-O-methyl-6-deoxy-β-1)-allopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside).     

藏药雪莲花的化学成分

菊科植物丛株雪兔子(Soussurea tridactyla Sch.-Bip. var. maidugonla S. W. Liou)为西藏藏族药物雪莲花的原植物之一,从中分离到九种化学成分,分别鉴定为芹菜索,芹菜素-7-葡萄糖甙,伞形花内酯,伞形花内酯-7-葡萄糖甙,东莨若素,对羟丛苯乙酮,3-吲哚乙酸,秋水仙碱及β-谷甾醇。     

滇重楼地上部分的甾体皂甙

从滇重楼Paris polyphylla Sm. var. yunnanensis (Fr.) H-M.地上部分分离得到3个甾体皂甙,经光谱测定和化学降解证明其化学结构分别为:偏诺皂甙元3O-α-L-鼠李吡喃糖基(1→2)〔α-L-鼠李吡喃糖基(1→4))-β-D-葡萄吡喃糖甙(A);孕甾-5,16-二烯-3β-醇-20-酮,3β-O-α-L-鼠李吡喃糖基(1→2)〔α-L-鼠李吡喃糖基(1→4)〕-β-D-葡萄吡喃糖甙(B);孕甾-5,16-二烯-3β-醇-20-酮,3β-O-α-L-鼠李吡喃糖基(1→2)〔α-L-鼠李吡喃糖基(1→4)-α-L-鼠李吡喃糖基(1→4)〕-β-D-葡萄吡喃糖甙(C)。甙A、B和C在滇重楼根中尚未发现,甙C系首次从重楼属植物中获得,而甙A具有止血的活性。     

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.