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从栓皮栎(Quercus variabilisBl.)虫瘿中分离了2对平衡互变异构体和4个单体化合物,通过光谱数据和化学方法鉴定:G-1为1-O(3′-没食子酰基)没食子酰基-β-D-葡萄吡喃糖和1-O-(4′-没食子酰基)没食子酰基-β-D-葡萄吡喃糖的平衡互变异构体,G-2为3-O-没食子酰基-没食子酸和4-O-没食子酰基--没食子酸的平衡互变异构体,-3O一1,6-二-O没食子酰基-β-D-葡萄吡喃糖,G-4为1,2,3,6-四-O-没食子酰基-β-D-葡萄吡喃糖,G-5为1-O-没食子酰基-β-D-葡萄吡喃糖,G-6为没食子酸甲酯。对G-1、G-3和G-4进行初步的抗肿瘤、抗脂质过氧化和抗血小板聚集活性实验。 相似文献
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小麦—中间偃麦草抗条锈衍生系的分子细胞遗传学研究 总被引:10,自引:1,他引:10
应用缺体回交法,以部分阿勃缺体为母本,中4为父本,培育出1个对目前条锈病优势小种和新小种高抗至免疫的小麦--中间偃麦草衍生系N9025-3-3-2-1-1。研究表明,该选系在形态学和细胞学上已经基本稳定,染色体构型为2n=42=21“,抗病性来自中间偃麦草(Thinopyron intermedium)。以中间偃麦草DNA为探针,对N9025-3-3-2-1-1进行基因组原位杂交分析结果证明,它为小麦-中间偃麦草异代换-易位系。 相似文献
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喉毛花化学成分研究 总被引:1,自引:0,他引:1
从龙胆科植物喉毛花(Comastoma pulmonarium(Turez.) Toyohuni)中分离到6个仙酮类化合物,经化学及光谱方法分别鉴定为1,8-二羟基-3,5-二甲氧基仙酮(I),1,8-二羟基-3,7-二甲氧基仙酮(II),I-羟基-3,7,8-三甲氧基仙酮(Ⅲ),8-羟基-1,3,5-三在仙酮(IV),1,3,8-三羟基-7-甲氧基仙酮(V),I-O-β-D-吡喃葡萄糖-3,8-二羟基-7-甲氧基仙酮(VI)以及齐墩果酸(VII),当药黄素(Swertisin)(VIII)。其中VI为新化合物,命名为喉毛花甙(Comastomaside)。 相似文献
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紫茎泽兰花的化学成分 总被引:20,自引:0,他引:20
从紫茎泽兰( Eupatorium adenophorum ) 的花中分离得到12 个化合物, 其中紫茎泽兰内酯为一新的杜松烯类倍半萜内酯化合物, 其它为2 - 乙酰氧基- 3 , 4 , 6 , 11 - 四去氢杜松烷- 7 - 酮, 7 - 羰基泽兰酮, 克拉维醇, 丁香酚- O- β- 吡喃葡萄糖甙, 5 , 4′- 二羟基- 3 ,6 - 二甲氧基- 7 - O- β- 吡喃葡萄糖基黄酮, 5 , 4′- 二羟基- 6 ,7 - 二甲氧基- 3 - O- β- 吡喃葡萄糖基黄酮,3 , 5 , 4′- 三羟基- 6 ,7 - 二甲氧基黄酮等化合物。 相似文献
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弯蕊开口箭中的新甾体配糖体 总被引:11,自引:0,他引:11
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。 相似文献
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从沙打旺分离到15个化合物,经光谱分析,理化实验及与已知化合物比较,鉴定了11个化合物,其中两个为四环三萜类化合物,分别鉴定为(20R,24S)-3.16-二羰基-6α,25-二羟基-20,24-环氧-9.19-环羊甾酮(9)和(20R,24S)-3,16-二羰基-6α,25-二羟基-20,24-环氧-9,19-环-23氧-羊毛甾酮(10)。 相似文献
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报道了一种新的具有抗吗啡镇痛活性的肽的分离纯化,并进行部分一级结构测定.狗脑先经醋酸提取,冷冻成干粉,然后上SephadexG-50和S-SepharoseF.F柱,最后经RP-HPLC纯化,鉴定纯度后,测定其抗吗啡镇痛活性,通过SDS-PAGE法测得其分子量为8.9kD.氨基酸序列分析测得该肽的N端序列为:V-I-S-V-A-D-W-T-Q-I-F-T-M-R-Y-F-I-T-G-Y-H-Q-D-Y-X-G-L-H-I-G.经部分一级结构同源序列检索,未见与此有同源的蛋白质的报道,暂命名该肽为CC4肽 相似文献
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喉毛花化学成分研究 总被引:2,自引:0,他引:2
从龙胆科植物喉毛花(Comastoma pulmonarium(Turez.) Toyohuni)中分离到6个仙酮类化合物,经化学及光谱方法分别鉴定为1,8-二羟基-3,5-二甲氧基仙酮(I),1,8-二羟基-3,7-二甲氧基仙酮(II),I-羟基-3,7,8-三甲氧基仙酮(Ⅲ),8-羟基-1,3,5-三在仙酮(IV),1,3,8-三羟基-7-甲氧基仙酮(V),I-O-β-D-吡喃葡萄糖-3,8-二羟基-7-甲氧基仙酮(VI)以及齐墩果酸(VII),当药黄素(Swertisin)(VIII)。其中VI为新化合物,命名为喉毛花甙(Comastomaside)。 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