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1.
从菊状千里光(Senecio laetus)全草中分离得到7个Jacaranone类化合物,它们的结构运用现代波谱技术确定为jacaranone (1);3-hydroxy-2,3-dihydrojacaranone methyl ester (2);1-羟基-4-氧代-2,5-环己二烯-1-醋酸乙酯(3);2-jacaranone酰基-α-D-吡喃葡萄糖酯和2-jacaranone酰基-β-D-吡喃葡萄糖酯的混合物(4、5); l-jacaranone乙酯-β-D-吡喃葡萄糖苷(6);1-羟基-4-氧代-2,5-环己二烯-1-醋酸(7).首次报道菊状千里光中Jacaranone类化合物的存在,支持了国外学者认为该类化合物是千里光属植物特征次生代谢产物的推论.  相似文献   

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通过标本(包括模式标本)检查,发现稻城千里光(Senecio daochengensis Y. L. Chen)与黑褐千里光(S. atrofuscus Grierson)属于同一种植物,故将前者处理为后者的异名。提供了黑褐千里光的地理分布图及其与近缘种的检索表。  相似文献   

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千里光在皮肤洗剂中的应用   总被引:1,自引:0,他引:1  
千里光在皮肤洗剂中的应用张卫明,赵伯涛,马世宏,王红(内贸部南京野生植物综合利用研究所南京210042)徐世和,郭荣松,曹阳(江苏蒲公英保健品公司兴化225732)引言千里光SeneczbscandensBuch.-Ham。为菊科多年生草本植物,广泛...  相似文献   

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本文对新疆千里光进行了化学成分研究,从中分离鉴定了12个化合物,分别为千里光碱(1)、千里光菲灵碱(2)、全缘千里光碱(3)、克式千里光碱(4)、异鼠李素(5)、槲皮素(6)、异鼠李素-3—O-β-D-半乳糖苷(7)、8-(2"-pyrrolidinone-5”-y1)-isorhamnetin(8)、pseudotaraxasterc1(9)、咖啡酸(10)、β-谷甾醇(11)、卢-胡萝卜苷(12)。除1—3外,其余9个化合物均为首次从该植物中分离得到。  相似文献   

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款冬的胚胎学   总被引:4,自引:0,他引:4  
刘建全 《西北植物学报》2001,21(3):T001-T003
系统报道了中藏药款冬大小孢子的发生、雌雄配子体发育和胚胎的发育过程,药壁发育双子中型,绒毡层发育接近菊科中的“The Comos bipinnatus”型;成熟花粉为3细胞型;单株被,薄珠心,倒生胚珠,具发达的珠被绒毡层;胚囊发育4孢子型,接近五福花(Adoxa)型胚囊,受精作用属于有丝分裂前配子体融合类型,胚乳发育为核型,胚胎发育紫菀型千里光变型。讨论了该种胚胎学特征的生态学及系统学意义。  相似文献   

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千里光等五种中草药的体外抑菌实验   总被引:10,自引:0,他引:10  
本文对千里光、野菊花、地锦草、龙葵、马齿苋五种中草药分别进行体外抑菌实验。观察结果表明,千里光等五种中草药煎剂对金黄色葡萄球菌,白喉杆菌、伤寒杆菌、大肠杆菌、变形杆菌和痢疾杆菌显示程度不等的抑制作用,以千里光、马齿苋、地锦草三味药的抑菌作用更为明显。本研究为判断和解释千里光等药物的清热解毒药理作用提供了有益的资料。  相似文献   

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在光学显微镜和扫描电镜下,对分布于新疆的菊科千里光族4属26种植物的花粉进行了观察。根据萌发沟长短和外壁纹饰待征将各属分成二种类型:(1)具长萌发沟:有橐吾属、千里光属和多榔菊属。(2)具短萌发沟:仅有款冬属。由此可看出,款冬是较独立的一类,与其余各属在亲缘关系上相距较远。花粉形态特征为多榔菊属分类地位的探讨提供了资料。同时也为橐吾属两新种的成立提供了孢粉学证据。  相似文献   

9.
掌裂橐吾的胚胎学   总被引:2,自引:0,他引:2  
首次报道了掌裂橐吾的胚胎发育过程。药壁发育双子叶型;绒毡层发育属、The Cosmos bipinnatus”型,成熟花粉为3细胞型;单珠被,薄珠心,倒生胚珠;具发达的珠被绒毡层;胚囊发育为4孢子型,类似德鲁撒型(Drusa);胚乳发育为核型,胚胎发育为紫菀型千里光变型。  相似文献   

10.
了款冬属的核形态。染色体间期为简单型与复杂型的过渡型;前期染色体为近基型的过渡型。染色体较小,核型不对称,具明显的二型性;数目与核型公式为2n=60=42m+10sm_6st+2t。比较发现款冬的核型不同于千里光族中已有的核型记载,其核型特征似乎与它独特的形态特征相联系,具有重要的系统学意义。  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   

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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   

18.
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   

19.
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   

20.
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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