首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 828 毫秒
1.
番荔枝化学成分研究(7)   总被引:1,自引:0,他引:1  
从番荔枝(Annona squamosa L.)种子中得到化合物1、2和4,化合物2和4分别为已知化合物motrilin(莫垂林,2)和bullatanocin(布拉他诺辛,4)。化合物1的化学结构经IR、MS、^1H NMR及^13C NMR谱分析及其乙酰化物(1a)的MS、^1H NMR谱分析推定如(1)式并命名为22-表-莫维查灵(22-epi-molvizarin)。  相似文献   

2.
刺果番荔枝种子中的新环肽—刺果番荔枝环肽A   总被引:3,自引:0,他引:3  
从刺果番荔枝种子中得到1个新环肽,命名为刺果番荔枝环肽A(annomuricatinA)通过多种2D-NMR技术、pos.FAB-MS和氨基酸分析,其结构确定为坏(脯-苯丙-缬-丝-丙-甘),是1个环六肽。  相似文献   

3.
大花哥纳香化学成分研究   总被引:2,自引:0,他引:2  
从大花哥纳香(GoniothalamusgrifithiHokf.etThoms)的茎枝分得12个化合物,经光谱(IR,MS,NMR,2DNMR)分析,鉴定其中7个为苯乙烯内酯:goniothalamin(1)、9deoxygoniopypyrone(2)、altholactone(3)、goniodiol(4)、goniotharvensin(5)、goniofufurone(6)和8acetylgoniotriol(7)。另5个化合物鉴定为番荔枝内酰胺(squamolone,8)、乔松素(pinocembrin,9)、琥珀酸(succinicacid,10)、β谷甾醇(βsitosterol,11)和豆甾醇(stigmasterol,12)。化合物1~3和5~10均为首次从该植物分得。  相似文献   

4.
滇产圆滑番荔枝中的番荔枝内酯   总被引:3,自引:0,他引:3  
从滇南产的圆滑番荔枝的种子中得到4个番荔枝内酯,4-dexoxycherimolin-2(1),cherimolin-2(2),annoninI(3)和desacetyluvaricin(4)。其中1为新化合物。  相似文献   

5.
从番荔枝(Annona squam osa L.)的种子中分离到A1—A7共7个化合物,其中A2、A3和A5为新的番荔枝内酯,分别命名为新-去乙酰紫玉盘素(neo-desacetyluvaricin, A2)、新阿诺宁乙(neo-annonin B, A3)和新牛心番荔枝素甲(neo-reticulatacin A, A5)。  相似文献   

6.
斜脉暗罗素甲—具有C5—OH的单四氢呋喃环型番荔枝内酯   总被引:2,自引:0,他引:2  
从斜脉暗罗(Polyalthia plagioneura Diels)的种子中分离到化合物P4 及P5,经IR、1H-NMR、13 C-NMR及MS谱鉴定,P4 为海南哥纳香甲素,P5 为具有C5-OH 的单四氢呋喃环型番荔枝内酯,命名为斜脉暗罗素甲(plagionicin A)。  相似文献   

7.
从景洪哥那香茎中得到3个具有抗癌活性和杀虫作用的番荔枝内醌化合物,goniothalamicin(1)cheliensisinB(2)〈CheliensisinC(3),其中2,3为新化合物。  相似文献   

8.
从海南哥纳香(Goniothalam ushow iiMerr. etChun)的种子分离到结晶V、VI和VII。根据它们的IR、1H-NMR、13C-NMR、MS分析及衍生物光谱分析,它们均属番荔枝内酯的新类型——裂双四氢呋喃型番荔枝内酯。晶V和晶VI分别命名为海南哥纳香丁素(how iicin D)和戊素(how iicin E)。晶VII系两个平面结构相同的化合物海南哥纳香己素和庚素(how iicins F,G)的混晶  相似文献   

9.
滇产刺果番荔枝种子中的acetogenin类化合物   总被引:5,自引:0,他引:5  
滇产刺果番荔枝种子中的acetogenin类化合物李朝明1穆青1孙汉董1郑惠兰2陶国达2(1中国科学院昆明植物研究所植物化学开放实验室,昆明650204)(2中国科学院西双版纳热带植物园,云南勐腊666303)ACETOGENINSFROMSEED...  相似文献   

10.
刺果番荔枝中的番荔枝内酯(2)   总被引:5,自引:0,他引:5  
从刺果番荔枝的种子中分离了3个具有酮基的单四氢呋喃环型的番荔枝内酯S7,S8和S10,根据它们的[a]D,^1HNMR,^13CNMR,MS及IR谱分析,分别推定为新-异阿诺纳辛-10-酮(S7)、新阿诺纳辛-10-酮(S8)和异-新阿诺纳辛-10-酮(S10)。  相似文献   

11.
12.
13.
14.
15.
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   

19.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号