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合欢花化学成分的研究(Ⅱ) 总被引:13,自引:0,他引:13
从合欢花甲醇提取物的石油醚和乙酸乙酯部分分离得到7个化合物,经化学方法和波谱法鉴定为:二十四烷酸(1)、二十八烷醇(2)、α-菠甾醇(3)、山奈酚(4)、槲皮素(5)、α-菠甾醇-3-O-β-D葡萄糖苷(6)、山奈酚-3-O-α-L鼠李糖苷(7).除二十四烷酸以外,以上化合物均为首次从该植物中获得. 相似文献
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通过使用乙酸乙酯溶剂对沉水植物苦草(Vallisneria natans)全草进行超声连续提取,采用硅胶柱色谱法和光谱分析法分离和鉴定化学成分。从苦草中分离到6个化合物:6,10,14-三甲基-2-十五酮(1)、棕榈酸(2)、4,22-二烯-3β-豆甾酮(3)、5α,豆甾烷-3,6-二酮(4)、硬脂酸(5)、棕榈酸乙酯(6)。化合物1—6为首次从该植物中发现。 相似文献
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山木通的化学成分研究 总被引:1,自引:0,他引:1
目的:对毛茛科铁线莲属植物山木通的化学成分进行提取、分离和鉴定。方法:用不同浓度乙醇提取,利用硅胶、SephadexLH-20、ODS柱色谱法对山木通的化学成分进行分离,根据理化性质和MS、NMR光谱数据进行结构鉴定。结果:经鉴定得到7个化合物,分别为β-谷甾醇(Ⅰ);正二十二烷(Ⅱ);3-羰基齐墩果烷(Ⅲ);正十六烷酸(Ⅳ);正二十六烷酸(Ⅴ);丁香酸(Ⅵ);5-羟基4-氧代戊酸(Ⅶ)。结论:所得化合物均为首次从该种植物中得到。 相似文献
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采用硅胶柱色谱和葡聚糖凝胶LH-20,从火麻仁70%乙醇提取物的氯仿和乙酸乙酯萃取部位分离得到6个化合物。经理化鉴定和波谱方法鉴定方法确定为CannabsinA(1).β-谷甾醇(2)、胡萝卜苷(3)、正二十四烷酸(4)、甘露醇(5)、棕榈酸(6)。 相似文献
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利用Sephadex LH-20,硅胶柱色谱和硅胶制备薄层色谱等分离方法反复分离纯化,从小花清风藤(Sabia parviflora Wall.ex Roxb)中分离得到9个化合物,通过波谱数据分析分别鉴定它们为二十五烷酸(1)、木栓酮(2)、5-氧阿朴菲碱(3)、3-氧化齐墩果酸甲酯(4)、齐墩果酸(5)、羽扇豆-20(29)-烯-3-酮(6)、羽扇豆醇(7)、β-谷甾醇(8)、脱镁叶绿甲酯酸(9)。化合物2,6、7、9首次从该植物中分离得到。 相似文献
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紫花苜蓿化学成分的研究(英文) 总被引:1,自引:0,他引:1
为研究紫花苜蓿(Medicago scttiva L.)地上部位的化学成分,通过溶剂萃取、硅胶柱色谱、凝胶柱色谱分离纯化,从紫花苜蓿地上部分分离得到9个化合物,根据质谱和核磁共振数据鉴定为小檗碱(1)、大黄素(2)、大黄素8-O-β-D-葡萄糖苷(3)、soyαsαpogenol B-3-O-β-glcA(4)、邻羟基苯甲酸(5)、反式对羟基肉挂酸(6)、顺式对羟基肉桂酸(7)、正三十烷醇(8)和β-胡萝卜苷(9)。其中化合物1—4为首次从苜蓿属植物中分离得到。 相似文献
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为探讨山茶科(Theaceae)柃木属植物米碎花(Eurya chinensis R. Brown)茎枝的化学成分,从米碎花茎枝95%乙醇提取物中分离得到8个化合物,根据现代波谱技术和文献对照,鉴定其结构分别为:高根二醇(1)、白桦酸(2)、木栓酮(3)、羽扇豆醇(4)、β-谷甾醇(5)、豆甾醇(6)、邻羟基苯甲醛(7)、正二十九烷醇(8)。所有化合物均为首次从该植物中分离得到。 相似文献
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运用硅胶、sephadex LH-20等柱色谱,从木蹄层孔菌子实体的乙醇提取物分离得到12个化合物,通过单体的理化性质、NMR和MS技术鉴定单体的结构为3-十六碳酸酯-7,22-二烯麦角甾醇(1),十八烷酸(2),棕榈酸(3),7,22-二烯麦角甾-3-酮(4),麦角甾-7,22-二烯-3-醇(5),5,8-过氧麦角甾-6,22-二烯-3-醇(6),3,3-二甲氧基-7,22-二烯麦角烷(7),28-乙酰白桦脂醇(8),白桦脂醇(9),β-羟基十八烷酸(10),9,10-二羟基十八烷酸(11),瑞香素(12)。采用Alamar Blue法检测单体化合物对人肺癌细胞NCI-H 460和人胃癌细胞SGC-7901的抑制活性。结果表明,化合物4对NCI-H 460细胞株的抑制活性最高,化合物9对SGC-7901的抑制活性最高。 相似文献
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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. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
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
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
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
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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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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
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
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