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1.
滇杠柳的化学成分   总被引:28,自引:0,他引:28  
从滇杠柳(Periploca forrestii)根茎中分得一个新强心甙元8-羟基杠柳甙元(3β,5β,8β,14β-四羟基-强心甾-20(22)-烯内酯(1),同时还获得杠柳甙元(2),杠柳甙(3),北五加皮甙E(4),胡萝卜甙(5)和熊果酸(6)。它们的化学结构经光谱和化学方法得以确定。  相似文献   

2.
杜仲的化学成分(再报)   总被引:3,自引:0,他引:3  
从杜仲(Eucommia ulmoides Oliv.)皮的甲醇提取物中分得4种结晶,鉴定为 liriodendrin(1),geniposidic acid(2),松脂醇二葡萄糖甙[( )-pinoresinol di-O-β-D-glucopyranoside](3)和胡萝卜甙(daucosterol)(4)。  相似文献   

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半卧狗娃花中的黄酮类化合物   总被引:2,自引:0,他引:2  
从半卧狗娃花(Heteropappus semiprost Griers)全草的乙醇提取物中分离并鉴定了7个黄酮类化合物,通过波谱分析及化学方法鉴定其结构为:3′,4′,5,7-四羟基黄酮(1),3′-甲氧基槲皮素(2),槲皮素-3-O-α-L-吡喃鼠李糖甙(3),槲皮素-3-O-β-D-吡喃半乳糖甙(4),异鼠李亭-3-O-β-D-吡喃半乳糖甙(5),槲皮素-3-O-α-L-吡喃鼠李糖(1→6)-β-D-吡喃葡萄糖甙(6),异鼠李亭-3-O-α-L-吡喃鼠李糖(1→6)-β-D-吡喃葡萄糖甙(7),其中化合物1~5为首次从本属植物中分离得到。  相似文献   

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从龙胆科植物抱茎獐牙菜(Swertia franchtiana H.smith)中分得3种(口山)酮甙,1种黄酮甙和1种三萜酸,通过光谱和化学等方法,分别鉴定为当药醇甙,当药黄素,芒果甙,1-O-[β-D-吡喃木糖-(1-6)-β-D-吡喃葡萄糖]-3,5-二甲氧基咄酮(XI)和齐墩果酸,其中晶 XI 为一新化合物。  相似文献   

5.
鹿衔草化学成分的研究(第1报)   总被引:20,自引:0,他引:20  
从鹿衔草中分离得到8种结晶,其中5种经分析鉴定为:高熊果酚甙(homoarbutin,1),肾叶鹿蹄草甙(renifolin,2),金丝桃甙(hyperin,3),2″-0-没食子酰基金丝桃甙(2″-0-galloylhyperin,4)和6′_0-没食子酰基高熊果酚甙(6′-0-galloylhomoarbutin,5)。除1外,其它成分均系在鹿衔草中首次分得。4是鹿衔草的主要成分具有很强的单宁活性,并具有扎氧化、清除脂质过氧自由基和抑制脂质过氧化活性。  相似文献   

6.
肉苁蓉中苯乙醇甙类成分的分离和鉴定   总被引:18,自引:3,他引:15  
从列当科药用植物肉苁蓉(Cistanche deserticola)中分得四个苯乙醇甙类成分,经光谱分析,确定这四个成分是海胆甙(echinacoside),肉苁蓉甙A(cistanoside A),麦角甾甙(acteoside)和2'-乙酰麦角甾甙(2'-acetylacteoside)。以上成分在该植物中属首次分得。  相似文献   

7.
通光藤甙F,G,H和I结构   总被引:19,自引:0,他引:19  
从通光藤(Marsdeniatenacissima)的茎中分离得到4个新的C21甾体甙———通光藤甙F(3),G(4),H(5)和I(6),以及2个已知化合物通光藤甙A(1)和B(2)。根据光谱数据和化学方法推定了其结构。同时,通过COLOC谱和二维核磁共振谱指定了这些化合物中甙元上11和12位的酯基确切连接位置。  相似文献   

8.
从三叶崖爬藤(Tetrastigma hemsleyanum Diels et Gilg.)的95%乙醇提取物中分离得到3个黄酮碳甙,经化学方法和光谱分析鉴定为:5,7,4′-三羟基黄酮-6-α-L-吡喃鼠李糖(1-4)-α-L-吡喃阿拉伯糖甙(1),5,7,4′-三羟基黄酮-8-α-L-吡喃鼠李糖(1-4)-α-L-吡喃阿拉伯糖甙(2),5,7,4′-三羟基黄酮-6,8-二-C-β-D-吡喃葡萄糖甙(3),1和2为新化合物,分别命名为崖爬藤甙和异崖爬藤甙.  相似文献   

9.
高山金粉蕨的黄酮类成分   总被引:3,自引:0,他引:3  
从高山金粉蕨(Onychiumcontigqum)地上部分的甲醇抽提物中分到8个成分:高山金粉蕨甲甙(1),高山金粉蕨乙甙(2),金粉蕨素(3),反式桂皮酸(4),瓦利甙(5),β-谷甾醇(6),胡萝卜甙(7)和蔗糖(8)。高山金粉蕨甲甙和乙甙是新成分,反式桂皮酸系首次从金粉蕨属中分到。化学结构用一维和二维核磁共振技术确定。  相似文献   

10.
蕺叶秋海棠化学成分的研究   总被引:8,自引:2,他引:6  
从蕺叶秋海棠(Begoma limprichtu Irmsh)全草中分得5个化合物,经理化性质和波谱分析,分别鉴定为:豆甾醇-3-O-β-D-葡萄糖甙-6’-十六烷酸酯(1),豆甾醇3-O-β-D-吡喃葡萄糖甙(2),芦丁(3),豆甾醇(4),胡萝卜甙(5)。  相似文献   

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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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
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  相似文献   

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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.  相似文献   

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