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。     

四川蜘蛛抱蛋的甾体皂甙

从四川蜘蛛抱蛋（Ａｓｐｉｄｉｓｔｒａ ｓｉｃｈｕａｎｅｎｓｉｓ Ｋ。Ｙ。Ｌａｎｇ ｅｔ Ｚ。Ｙ。Ｚｈｕ）根状茎中分离得到三个甾体皂甙,经光谱和化学方法分别鉴定为２２－甲氧基－５β－呋喃甾烷－１β,３β,４β,５β,２６－五羟基２６－Ｏ－β－Ｄ吡喃葡萄糖甙（１）,蜘蛛抱蛋皂甙（２）和原蜘蛛抱蛋皂甙（３）。（１）是一个呋喃甾醇型单糖链的新皂甙,（３）是本植物的主要皂甙。     

蜘蛛抱蛋根茎中的甾体皂甙

从蜘蛛抱蛋（ＡｓｐｉｄｉｓｔｒａｅｌａｔｉｏｒＢｌ．）根茎的甲醇提取物中分离得两个甾体皂甙。经波谱解析及化学降解证明其化学结构分别为薯芋皂甙元一３一Ｏ－［Ｂ－Ｄ－葡萄吡喃糖基（１→２）］－［Ｂ－Ｄ－木吡喃糖基（１→３）］－Ｂ－Ｄ－葡萄吡喃糖基（１→４）－Ｂ－Ｄ一半乳吡喃糖甙（即蜘蛛抱蛋甙ａｓｐｉｄｉｓｔｒｉｎ）及新静诺特皂甙元－３－Ｏ－［Ｂ－Ｄ－葡萄吡喃糖基（１→２）］～［Ｂ－Ｄ－木吡喃糖基（１→３）－Ｂ－Ｄ－葡萄吡喃糖基（１→４）一Ｂ－Ｄ－半乳吡喃糖甙,后者为一新试,命名为新蜘蛛抱蛋甙ｒｅｏａｓｐｉｄｉｓｔｒｉｎ。     

滇重楼地上部分的配糖体

从滇重楼ＰａｒｉｓｐｏｌｙｐｈｙｌｌａＳｍ．ｖａｒ．ｙｕｎｎａｎｅｎｓｉｓ（Ｆｒ．）Ｈ－Ｍ,地上部分,分离出４个微量的配糖体,经光谱分析和化学降解证明其化学结构分别为２５Ｓ－异钮替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃甙（Ａ）,２６－β－Ｄ－葡萄吡喃糖基－纽替皂甙元－３－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）,山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄吡喃甙（Ｃ）,７－Ｏ－α－Ｌ－鼠李吡喃糖基－山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄糖甙（Ｄ）。     

滇重楼地上部分的两个微量皂甙

从滇重楼地上部分中分离出两个新的微量的甾体皂甙ＰｏｌｙｐｈｙｌｌｏｓｉｄｅⅢ和Ⅳ,根据化学降解和光谱分析,它们的化学结构分别为２７－羟基－偏诺皂皂甙元－３－Ｏ［ａ－Ｌ－鼠李吡喃糖基（１→２）］［ａ－Ｌ－鼠李吡喃糖基（１→４－ａ－Ｌ鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃糖甙,２３β,２７－二羟基－偏皂甙元－３－Ｏ－［ａ－鼠李吡喃糖（１→２）］     

闭鞘姜根中的甾体皂甙

从闭鞘姜「Ｃｏｓｔｕｓ ｓｐｅｃｉｏｓｕｓ（Ｋｏｅｎｉｇ）Ｓｍｉｔｈ」根茎中分离出五个化合物。经波谱解析和化学降解,证明其化学结构分别为胡萝卜甙（Ａ）：薯芋皂甙元３－Ｏ－ａ－Ｌ鼠李吡喃糖基（１－２）－β－Ｄ－葡萄吡喃糖甙（Ｂ）;薯芋皂甙元３－Ｏ－ａ－Ｌ－鼠李吡喃糖基（１－２）「ａ－Ｌ－鼠李吡喃糖基（１－４）」β－Ｄ葡萄吡喃糖甙（Ｃ）;薯芋皂甙元－３－Ｏ－ａ－Ｌ－鼠李吡喃糖基（１－２）「β－Ｄ－葡萄     

慈溪麦冬甙A和B的结构

从浙江慈溪产中药麦冬（Ｏｐｈｉｏｐｏｇｏｎ ｊａｐｏｎｉｃｕｍ）中分离得到２个新的Ｃ２７甾体甙－－慈溪麦冬甙Ａ（２）和Ｂ（３）以及已知甙ｏｐｈｉｏｇｅｎｉｎ３－氧－α－Ｌ－鼠李糖吡喃基（１→２）「β－Ｄ－木糖吡喃基（１→３）」－β－Ｄ－葡萄糖吡喃甙（２）和ｏｐｈｉｏｇｅｎｉｎ ３－氧－α－Ｌ－鼠李糖吡喃基（１→２）「β－Ｄ－木糖吡喃基（１→３）」「β－Ｄ－葡萄糖吡喃基（１→４）」－β－Ｄ－葡萄糖吡     

大叶吊兰中一个新的甾体皂甙

从百合科植物大叶吊兰（Ｃｈｌｏｍｐｈｙｔｕｍ ｍａｌａｙｅｎｓｅ）根茎中分离得到１个新的呋甾烷型甾体皂甙,命名为大叶吊兰甙Ｅ（ｃｈｌｏｒｏｍａｌｏｓｉｄｅ Ｅ）。经波谱和化学方法证明明其结构为：２６－０－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙｌ－２２－ｈｙｄｒｏｘｙ－２５（Ｓ）－５ａ－ｆｕｒｏｓｔａｎ－１２－ｏｘｏ－３β,２６－ｄｉｏｌ－３－β－Ｄ－ｘｙｌｏｐｙｒａｎｏｓｙｌ（１→３）〖α－Ｌ－ａｒａ     

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.