五种开口箭属植物根状茎中甾体皂甙元的初步研究

薄层层析结果显示五种开口箭属植物根状茎中均含有甾体皂甙和甾体皂甙元,为开口箭属植物作为甾体药物资源提供了依据。     

五种开口箭属植物根状茎中甾体皂甙及甾体皂甙元的初步研究

薄层层析结果显示五种开口箭属植物根状茎中均含有甾体皂甙和甾体皂甙元 ,为开口箭属植物作为甾体药物资源提供了依据。     

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。     

优化黄姜中甾体皂甙元测定的研究

对传统的黄姜中甾体皂甙元的测定方法进行了改进。提取甾体皂甙元时采用微量样品以氯仿浸提代替传统的回 流抽提法,以Liebemann-Barcharad试剂显色,用分光光度法测定。测定结果准确,高效低成本且步骤简单,应用广泛。     

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）。     

薯蓣皂甙元的研究进展

我国是薯蓣资源大国,其有效成分薯蓣皂甙元是甾体激素的主要合成原料.对薯蓣皂甙元的鉴定、生物合成、提取、分离以及利用等研究进行综述.     

A、B环羟基和吡啶的溶剂效应对甾体皂甙元19-甲基化学位移的影响

我们在对十多个A、B环上有羟基取代的甾体皂甙元~1H NMR谱研究时发现,△~5-系列的甾体皂甙元1β-OH对19-Me的吡啶溶剂位移为0.30ppm,5β-系列的甾体皂甙元其1β、5β、6β-OH对19-Me的吡啶溶剂位移大约各自为0.15ppm,与不具有1β、5β或6β-OH的甙元相比较,其19-Me的化学位移(吡啶为溶剂)随1β、5β和6β-OH取代数目的增加而向低场位移约0.3、0.6和0.9ppm,并具有可加和性。     

胡芦巴湿渣用作脲醛树脂增量剂的研究

常规分析表明,提取甾体皂甙元后的胡芦巴制胶副产物中蛋白质含量41％,聚糖含量14％,脂肪含量低,适宜用作脲醛树脂增量剂。在脲醛树脂中加入胡芦巴残渣增量剂后,提高了胶液粘度,延长了脲醛树脂的适用期和固化时间,减小了固化后的收缩性。-25％的胡芦巴增量剂可提高三合板胶合强度15％以上,且能显著降低甲醛释放量。     

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。     

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.