金铁锁皂甙的研究

从金铁锁(Psammoslene tunicoides)根中分离到二个新的齐墩果烷型五环三萜皂甙Ⅰ、Ⅱ,经光谱测定和化学降解证明它们的化学结构为齐墩果烷-3α,16α-二羟基-12烯-23-酸-28-O-β-D-葡萄吡喃糖基(1—3)-β-D-葡萄吡喃糖基(1—6)-β-D-葡萄吡喃糖甙(Ⅰ)和齐墩果烷-3α,16α-二羟基-12烯-23-酸-28-O-β-D-葡萄吡喃糖基1—6[-β-D-葡萄吡喃糖基1—3]-β-D-葡萄吡喃糖甙(Ⅱ)。上述两个化合物的母核配基均为同一的物质,差异是糖的连接位置不相同。     

思茅藤的化学成分研究

从思茅藤(Epigynum auritum (schneid.)Tsiang et P.T.Li)的茎皮中分离到一个新的化合物,命名为思茅藤甙(Epigcoside)Ⅰ和已知化合物Ⅱ。通过光谱分析和化学反应证明,其结构为Ⅰ(+)—儿茶素-3-O-α-D-葡萄吡喃糖(1→6)-β-D葡萄吡喃糖甙((+)-catchin—3-O-α-D-glucopyranosyl-(1→6)-β—D-glucopyranoside;Ⅱβ-谷甾醇β-D-葡萄糖甙(β-sitosterol-β-D-glucoside)。     

仙茅中两个新的环阿尔廷醇型三萜皂苷

从仙茅(Curculigo orchioides）中分离得到2个新的环阿尔廷醉型三萜皂苷,通过波诺分析鉴定了它们的化学结构,即3β,11α,16β—三羟基环阿尔廷烷-24-酮-3-O-[β-D-吡喃葡糖(1→3)-β-D-吡喃葡糖(1→2)-β-吡喃葡糖]-16-O-α-L-阿拉伯糖苷(1)和(24S)-3β,11α,16β,24-四经基环阿尔廷烷-3-O-[β-D-吡喃葡糖(1→3)-β-D-吡喃葡糖(1→2)-β-D-吡喃葡糖]-24-O-β-D-吡喃葡糖苷(2)。     

晚香玉球茎中的一个新胆甾烷类配糖体

从晚香玉(Polianthes tuberosa L.)球茎中分离到3个胆甾烷类配糖体。经波谱分析鉴定,其中1个为新的胆甾烷类配糖体,即(22S)—胆甾烷-5-烯-1β,3β,16β,22,25-五醇1—O—β-D-葡萄毗喃糖基—16—O-β-D芹菜呋喃糖苷。     

古蔺雪胆中的新三萜皂苷

从采自四川汉源县的古蔺雪胆(Hemsleya penxianensis var.gulinensiks)中分到9个三萜皂苷化合物,通过化学反应和光谱方法鉴定了它们的结构。其中7个为已知化合物,分别为齐墩果酸-28-O-β-D-比喃葡萄糖苷(1),3-O-β-D-吡喃葡萄糖醛基齐墩果酸苷(3),3-O-β-D-吡喃葡萄糖醛基—齐墩果酸—28-O-α-L-吡喃阿拉伯糖苷(4),3-O-β-D-吡喃葡萄糖醛基—齐墩果酸—28-O-β-D-吡喃葡萄糖苷(5),3-O-α-L-阿拉伯糖基—(1→3)—β—D-吡喃葡萄糖醛基—齐墩果酸—28—O—β—D—吡喃葡萄糖苷(6),3—O—(6′—丁酯)—β-D-吡喃葡萄糖醛基—齐墩果酸—28-O-α-L-阿拉伯糖苷(7),3-O-(6′-丁酯)—β—D吡喃葡萄糖醛基—齐墩果酸—28-O-β-D-吡喃葡萄糖苷(8)。两个新化合物,即雪胆皂苷A(2)和雪胆皂苷B(9)。     

黑蒴中的单萜甙类化合物

自黑蒴(Melasma arvense[Benth.]H.-M.)根中分离鉴定了羟基-β-紫罗兰酮葡萄醣甙(hydroxy-β-ionone glucosid 1)和一新的环烯醚萜甙—桃叶珊瑚甙元-1-O-β-龙胆双醣甙(aucubigenin-1-O-β-gentiobioside 2)。     

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)     

大豆叶片淀粉的降解及淀粉降解酶

在90μmol m~(-2)s~(-1)光强以下可见大豆叶片淀粉的降解,降解速率为0.8～3.8mg淀粉dm~(-2)h~(-1)。淀粉降解通过水解及磷酸解两条途径,α,β—淀粉酶的最适pH5～6,磷酸化酶pH7～8。α—淀粉酶活力随叶片的成长显著增强,β—淀粉酶则有所减弱。叶片淀粉积累或消耗时此三酶活力无显著变化。 黄化小麦叶片照光转绿过程中此三酶活力变化不大。黄化玉米叶片照光转绿过程中磷酸化酶活力降低,β—淀粉酶活力增强。     

十个甾体皂甙元的~(13)C NMR谱

本文报道心不甘(Tupistra aurantiaca Wall et Backer)的十个甾体皂甙元:△~5一系列的3-epiruscogenin(1),3-epi-ruscogenin(2),tupisgenin(3)和aurantigenin(4),5-β-系列的ranmogenin A(5)、B(6)、C(7)、D(8)、△~(25(27))—pentrogenin(9)和1β、2β、3β、4β、5β、7α-hexahydroxy-spirost-25(27)-en-6-one(10)的~(13)C NMR的归属和解析的研究结果。     

β-昆虫蜕皮激素对菊花外植体分化的影响

把β-蜕应激素〔1〕加入基本培养基中,观察对菊花叶外植体分化芽和潜伏腋芽生长的影响,发现0.05—0.3毫克/升的β-蜕皮激素以1:10的比例分别与0.5—3.0毫克/升的6-(艹卡)基瞟呤(6-BA)配合,使能叶块组织成愈伤组织并分化出不定芽,但不分化形成根;与α-萘乙酸(NAA0)配合则易形成根而不分化芽:0.5—4.0毫克/升的β-蜕皮激素与6-BA或NAA配合能促进潜伏腋芽萌发;0.25—4.0毫克/升的β-蜕皮激素能使“无根苗”生根形成完整植株。由上可见,β-昆虫蜕皮激素的作用主要和生长素类似。     

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.