弯蕊开口箭中的多羟基甾体皂甙元

从弯蕊开口箭(Tupistra wattii Hook．f．)的新鲜根茎中分离出2个新的多羟基甾体皂甙元,分别命名为弯蕊皂甙元B(wattigenin B)(1)和弯蕊皂甙元C(wattigenin C)(2),同时分离到2个已知的甾体皂甙元——凯替皂甙元kitigenin(3)和铃兰皂甙元B(convallagenin B)(4)。通过波谱解析鉴定了这4个皂甙元的结构,并测定了它们在体外对肿瘤细胞K562和A2780a的细胞毒活性。化合物1～4为首次从该种植物中分离得到。     

弯蕊开口箭中一个新的甾体皂甙元

从云南民间抗炎药弯蕊开口箭（Ｔｕｐｉｓｔｒａ ｗａｔｔｉｉ Ｈｏｏｋ．ｆ．）的新鲜根状茎中分离到１个新的甾体皂甙元,命名为弯蕊开口箭甙元Ａ（ｗａｔｔｉｇｅｎｉｎ Ａ）,其结构通过光谱分析鉴定为螺甾－２５（２７）－烯－１β,２β,３β,４β,５β,６β－六醇;同时还分离到１个已知的甾体皂甙元,兰茂甙元Ｄ（ｒａｎｍｏｇｅｎｉｎＤ）。     

盾叶薯蓣地上部分的三个新甾体皂甙

从盾叶薯蓣Dioscorea zingiberensis Wright地上部分分离鉴定了四个甾体皂甙,经鉴定甙A为约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖甙;甙B为24α-羟基约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)]β-D-葡萄吡喃糖甙;甙C为约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)][β-D-葡萄吡喃糖基(1→4)]-β-D-葡萄吡喃糖基;甙D为约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)][β-D-葡萄吡喃糖基(1→3)]-β-D-葡萄吡喃糖甙。前三者为新化合物,分别命名为盾叶皂甙A_1、A_2、A_3(zingiberoside A_1、A_2、A_3),其中盾叶皂甙A_2的甙元为一新甾体皂甙元,命名为盾叶皂甙元(zingiberogenin)。     

广西蜘蛛抱蛋中一种甾体皂甙定性定量研究

为了进一步开发和利用广西甾体药源植物奠定基础 ,对广西蜘蛛抱蛋 (Aspidistra retusa K.Y.Langet.S.Z.Huang)块茎甾体皂甙化合物进行了提取分离。在分离得化合物中含量最高的甾体皂甙化合物 4经鉴定为 :偏诺甾体四糖皂甙 ,即 pennogenin-3-β-O-β-D-glucopyranosyl[-α-L-rhamno-pyranosyl(1 -2 ) ]-α-L-rham-no-pyanosyl(1 -4 ) -α-L-rhamnopyranosyl(1 -4 )。该化合物为首次从蜘蛛抱蛋属植物中分离得到。经 HPLC测定其在广西蜘蛛抱蛋中的含量为 1 .5 95 %。     

棕粑叶中甾体皂甙和皂甙元的分离鉴定

从棕粑叶(Aspidistra zongbayi K.Y.Lang et Z.Y.Zhu)根茎正丁醇提取物中分离得到两个甾体皂甙。通过物理和化学方法鉴定为蜘蛛抱蛋皂甙(3-0-{β-D-吡喃葡萄糖(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃葡萄糖-(1→4)-β-D-吡喃半乳糖}-薯蓣皂甙元)和原蜘蛛抱蛋皂甙。从正丁醇部分酸水解物中分到△~(3,5)-脱氧替告皂甙元、薯蓣皂甙元、静特诺皂甙元。从根茎中还得到β-谷甾醇。     

五指莲重楼的甾体皂甙(2)

从五指莲重楼根中(Paris axialis)分离鉴定了七个甾体皂甙,其中有一新甙Ⅶ,经MS、~1H NMR、~(13)C NMR和化学降解方法证明其化学结构为:24α-羟基偏诺皂甙元-3-O-α-L-鼠李吡喃糖基1→2[α-L-阿拉伯呋喃糖基1→4]-β-D-葡萄吡喃糖甙。     

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。     

裂果薯的化学成分研究——皂甙甲和乙

从裂果薯(Tacca plantaginea Drenth)中分离到甲、乙、丙三个甾体化合物。化物合甲和乙,经光谱解析和化学分析鉴定为两个新甾体皂甙。其中裂果薯皂甙甲(Ⅱ)为一个糖连接方式上不常见的皂甙(约茂皂甙元-3-O-β-D-吡喃葡萄糖(1→2)[α-L-吡喃鼠李糖(1→3)][α-L-吡喃鼠李糖(1→4)]-β-D-吡喃葡萄糖甙);裂果薯皂甙乙(Ⅲ)(约茂皂甙元-3-O-α-L-吡喃鼠李糖(1—2)[α-L-吡喃鼠李糖(1→3)]-β-D-吡喃葡萄糖甙)。丙为豆甾醇甙。     

弯蕊开口箭中的新甾体配糖体

从百合科植物弯蕊开口箭（Tupistra Hook,f．）的根茎中分离得到4个新的甾体配糖体,分别命名为弯蕊苷（wattoside)B-E(1-4),其中,3个多羟基呋甾型配糖体,另1个为强心苷,经化学降解和光谱分析,其化学结构分别鉴定为：22－0－甲基－25（R,S）,－呋甾烷－1β,3β,4β5β,22ξ,26β－六醇－26－O－β－D－葡萄吡喃糖苷（1）：22－O－甲基－26－O－β－D-葡萄吡喃糖基－25（S）－呋甾烷－5－烯－β,3β,22ξ,26β－甲醇－3－0－[O-β-D-葡萄吡喃糖基（1－4）]－β－D-半乳吡喃糖苷（2）;22－0－甲基－25（S)-呋甾烷－1β,2β,3β,4β,5β,22,26β－七醇－26－O-β－D－葡萄吡喃糖苷（3）和夹竹桃苷元－3－O－[O-β-D-葡萄吡喃糖基（1－2）]－α－L－鼠李吡喃糖苷,弯蕊苷E为开口箭属植物中首次分离到的强心苷。     

滇产植物皂素成分的研究——Ⅵ.滇重楼皂甙(2)

从滇重楼干根粉中分离出三个甾体皂甙,鉴定为薯芋皂甙元-3-O-α-L-鼠李吡喃糖(1→2)-β-D-葡萄吡喃糖甙V,偏诺皂甙元-3-O-α-L-鼠李吡喃糖(1→2)-β-D-葡萄吡喃糖甙Ⅵ,偏诺皂甙元-3-O-α-L-鼠李吡哺糖(1→4)-α-L-鼠李吡喃糖(1→4)-〔α-L-鼠李吡喃糖(1→2)〕-β-D-葡萄吡喃糖甙Ⅶ.皂甙Ⅵ和Ⅶ已显示出有趣的生理活性。     

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.