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 15 毫秒
1.
宽叶泽苔草Caldesia grandis隶属泽泻科Alismataceae,是一种珍稀濒危水生植物。其化学成分迄今未见报道。本文利用气质联用的方法鉴定了该植物的43种化学成分,并总结了已报道的其近缘泽泻属Alisma、慈姑属Sagittaria、刺果泽泻属Echinodorus植物的化学成分,据此进行化学分类学分析:它们的特征化学成分是二萜,宽叶泽苔草和泽泻属植物的二萜成分是处于二萜生源合成途径最顶端的kaurane类型;慈姑属植物的二萜成分既有处于该途径底端的clerodane型、中间的pimarene型,也有顶端的kaurane型、abietene型二萜;刺果泽泻属植物的二萜成分是处于该途径底端的clerodane型。宽叶泽苔草和泽泻属植物都有桉叶烷型和愈创木烷型的倍半萜。因此宽叶泽苔草和泽泻属植物的亲缘关系比慈姑属、刺果泽泻属植物的近,由此推测它们的进化层次可能依次是刺果泽泻属植物、慈姑属植物、泽泻属植物、宽叶泽苔草。  相似文献   

2.
本文利用光镜及扫描电镜对湖北省泽泻科、水鳖科、眼子菜科及茨藻科11属29种1变种1变型植物(另加采于湛江的软骨草)的花粉形态进行了研究,发现泽泻科植物花粉具多个圆形萌发孔,外壁表面为小刺状纹饰;茨藻科植物花粉具远极单槽,表面为绉波状纹饰;眼子菜科及本文研究的水鳖科植物花粉均无萌发孔,分别具网状和小刺状饰纹饰。1.茨藻科植物花粉最原始,泽泻科花粉较进化,眼子菜科花粉较水鳖科花粉进化;2.泽泻属与泽苔草属花粉较慈姑属花粉原始;3.鞘叶眼子菜亚屈花粉较眼子菜亚属的花粉处于更高演化阶段;4.多孔茨藻花粉在该科中最原始。本文工作尚对易变形水生植物花粉形态研究方法进行了尝试。  相似文献   

3.
Two annual (Echinodorus rostratus (Nutt.) Engelm., Sagittaria calycina Engelm.) and 3 perennial (Alisma subcordatum Rat., S. brevirostra Mack & Bush, S. latifolia Wild.) species of Alismataceae were compared to determine differences in reproductive effort and timing. The annuals produce flowers and fruits earlier and later than the perennials and, under optimal conditions, the annuals also produce more (but smaller) seeds annually per plant. Populations of the annuals occur on exposed mud and are erratically abundant from year to year, while populations of the perennials are more stable. Seed viability of the annuals decreases more slowly over time. There is general congruence of these life-history attributes with the concepts of “r” and “K” strategies.  相似文献   

4.
Karyology of some Brazilian species of Alismataceae   总被引:1,自引:0,他引:1  
The family Alismataceae ( sensu Cronquist) comprises 11 genera and 75 species of aquatic and semiaquatic herbs. In Brazil, only the two most speciose genera, Echinodorus Rich. ex Engelm. and Sagittaria L., are present. The chromosome number 2 n  = 22 is common to all species. We present karyotypes for eight species, together with their asymmetry index (TF%) and total chromatin length (TCL). All karyotypes have high karyotypic asymmetry and TCL, due to their large and mostly acrocentric chromosomes. The chromosomal evolution of the Alismatidae group is discussed.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 143 , 159−164.  相似文献   

5.
林祁  刘克明 《植物研究》1997,17(1):47-49
湖南植物新记录区计10种,隶属于6科8属,泽苔草属为新记录;沼生繁缕,大苗山柯,白毛青冈,肾叶天胡荽,金草,剑叶耳草,多花茜草,秃果华千里光,崇澍华千里光,宽叶泽苔草为新记录种。  相似文献   

6.
Extracts of Laetia procera (Flacourtiaceae) displayed significant in vitro activity against Plasmodium falciparum. P. falciparum bioassay guided fractionation of a trunk bark extract of this plant led to the isolation of six clerodane diterpenoids (1-6) and a butanolide (7). Five of these compounds are new and called Laetiaprocerine A-D (3-6) and Laetianolide A (7). Their structures were established on the basis of 1D and 2D NMR experiments. Absolute configurations of 1 and 2 were determined by a modified Mosher's method and the absolute configuration of 5 by chemical correlation. The clerodane diterpenoids displayed activities against P. falciparum with an IC50 down to 0.5 microM on FCb1 and F32 strains, and also cytotoxicity toward human tumor cell line MCF7. The most active compound showed a selectivity index of 6.8. Some of these compounds also displayed activities against Leishmania amazonensis amastigote axenic stages and promastigote.  相似文献   

7.
中国慈姑属系统发育的研究   总被引:2,自引:0,他引:2  
本文研究了中国慈姑属植物间的系统发育关系。选取了12个与该属系统发育有较重要关系的特征,将8个已知分类群与外类群刺果泽泻属进行了比较。应用数量分支分析的Farris-Wagner方法,建立了中国慈姑属系统发育分支图。讨论了各分类群间的系统发育关系、该属起源和数量分支分析方法等问题。  相似文献   

8.
宽叶泽苔草(Caldesia granis Samuel)。是一种珍稀濒危水生植物。它曾经一度被认为已经从中国大陆灭绝,但最近又在湖南省的一个高山沼泽中被发现。本文首次报道了依据上述新发现地点的宽叶泽苔草材料进行的细胞学研究结果。核型分析结果表明:本种染色体数目为22,其染色体组型高度不对称。结合前人对宽叶泽苔草一些近缘种的细胞学及古生物学研究结果,作者认为泽苔草属植物很可能是泽泻科中最进化的一个属。  相似文献   

9.
The floral organogenesis of Caldesia grandis Samuel. was observed under scanning electron microscope (SEM). The primordia of the floral appendage were arranged according to a trimerous plan and in acropetal succession. Three sepal primordia were first ini  相似文献   

10.
Five clerodane diterpenoids have been isolated from the aerial parts of Pulicaria wightiana along with 3'5,6-trihydroxy-3,4',7-trimethoxyflavone and 2-methyl-5-hydroxy-chroman-4-one. The structures and stereochemistry of the compounds were established from spectral (mainly 1D and 2D NMR) studies. The last two compounds were not reported earlier from this plant. The antibacterial activity of the diterpenoids were studied.  相似文献   

11.
Errors by Rataj in lecto- and neotypification of five names inEchinodorus are corrected. These errors include the selection of lectotype specimens that were not cited in the protologue and the designation of neotypes from syntypes. Lectotypes for four of the names are designated here. The other is not typified at this time, as we have as yet been unable to examine the cited collections. In addition, a lectotype is designated for the Linnaean nameAlisma cordifolia, a name for which Rataj did not choose a lectotype. A new species,Echinodorus reticulatus, is described and illustrated. Five new combinations at the subspecies level are proposed, with most of these subspecies having a distribution from Central America to Paraguay and Argentina.  相似文献   

12.
The investigation ofPalafoxia rosea afforded in addition to known compounds five new labdane derivatives and five pimarene derivatives. The structures are elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic situation of the genus is discussed briefly.  相似文献   

13.
From the bulbils of Dioscorea bulbifera L. var sativa, two clerodane diterpenoids, Bafoudiosbulbins F (1) and G (2), together with five known compounds: Bafoudiosbulbins A-C, 3,5,4'-trihydroxy-3'-methoxybibenzyl, and kaempferol were isolated. Their structures were established by spectroscopic techniques, including (1)H, (13)C NMR, NOESY, ROESY, COSY, TOCSY, HSQC, and HMBC. The relative stereochemistry of compounds 1 and 2 was assigned on the basis of X-ray crystallographic diffraction analysis. Furthermore, the structure of Bafoudiosbulbin B was revised using extensive 2D NMR techniques as well as chemical transformation.  相似文献   

14.
Twelve new clerodane diterpenoids named callicarpanes A–L ( 1 – 12 ), together with eight known compounds ( 13 – 20 ), were isolated from Callicarpa integerrima. Their structures were determined by comprehensive spectroscopic data. The calculated chemical shifts were used to identify relative configurations using DP4+ analysis. The absolute configurations (AC) were assigned based on quantum chemical calculations and X-ray single-crystal diffraction methods. Compounds 1 , 3 , 5 , 9 , 10 , 12 , 15 , 16 , and 19 showed significant inhibitory activity for NLRP3 inflammasome activation, with the IC50 against lactate dehydrogenase (LDH) release ranging from 0.08 to 4.78 μM. Further study revealed that compound 10 repressed IL-1β secretion and caspase-1 maturation in J774A.1 cell as well as blocked macrophage pyroptosis.  相似文献   

15.
克罗烷二萜的昆虫拒食活性及构效关系研究   总被引:5,自引:0,他引:5  
徐建华  陈焕明 《昆虫学报》1998,41(4):366-370
以饲料柱称重法测定25个克罗烷二萜新化合物对亚洲玉米螟Ostrinia furnacalis(Guenee)5龄幼虫的拒食活性,并进行构效关系分析。结果表明:立体效应对拒食活性意义 重大;C9边链、C18位的酯基对活性具有一定影响;C4处的螺环氧结构看来并非活性所必需。且在25μg/mL时选择法测定中,活性最高的化合物拒食率为57.9%,而500/μg/mL时非选择法测定中拒食率为43.2%。  相似文献   

16.
《Phytochemistry》1986,25(7):1677-1680
A new diterpenoid furnolactone having molecular formula C20H22O6, has been isolated from the stems of Tinospora cordifolia. Its spectral characteristics are very similar to the clerodane diterpenoids. Its structure followed from 1HNMR and 13CNMR studies.  相似文献   

17.
An instance is presented in which skeletal features of chemical constituents provide valuable information on the phylogenetic relationship in plant species. A close examination of diterpenoid constituents was carried out on three Portulaca species, each of which has a different basic chromosome number. Major diterpenoid constituents in P. cv. Jewel, P. pilosa and P. grandiflora were found to be, respectively, of the clerodane ([6.6]-fused ring), prinziane ([7.6]-fused ring) and portulane ([7.5]-fused ring) types. From a biosynthetic viewpoint, a linear evolutionary relationship among the Portulaca plants in question would be assumed. All the diterpenoids found in the above three species have 1,4-dihydroxy-2-buten-2-ylethyl side chains and the relevance of this feature for chemical systematics of Portulaca plants is pointed out.  相似文献   

18.
《Phytochemistry》1996,42(6):1653-1656
Two new diterpenoids with the furanoid clerodane and dinorlabdane carbon skeletons, termed respectively (+)-7α-acetoxybacchotricuneatin D and (−)-3β-hydroxy-15,16-dinorlabd-8(17)-ene-13-one, were isolated from copaiba oil and their structures were elucidated by NMR spectroscopy.  相似文献   

19.
The chemical components of different genera and species of Taxaceac have been analyzed in order to provide the data for discussion of the systematic position of this family. A characteristic component kayaflavone from the leaves of Torreya grandis cv. ‘Merrillii' has been reported in our previous paper. Recently we have obtained also a new diterpene torreyagrandate from the leaves of this species. The present paper deals with our preliminary study on essential oil composition of the leaves in the same species. 26 components have been identified. Three of them, limonene, α-pinene and δ-3-carene, are the main ones, with their contents being 44.24%, 20.75% and 4% respectively. The essential oilalso contains torreyol which is a characteristiccomponent in this species.  相似文献   

20.
The endangered marsh herb, Caldesia grandis, is native to China. We investigated the spatial structure of the genetic variation of three populations of C. grandis using RAPD markers and spatial autocorrelation analysis, based on the method of equal distance interval. A total of 157 individuals were sampled from four patches collected from the region of Hunan and Yunnan Provinces, China. Among the polymorphic bands generated by seven selective primers, polymorphic bands with frequencies ranging from 20 to 80% were used to calculate Moran's I spatial autocorrelation coefficient for each patch. We found significant spatial structure of genetic variation in the three patches in Bei Hai (BH) (patches BH-1 and BH-2) and Guai Hu (GH) (patch GH-1) populations of C. grandis (with significant positive autocorrelation within the short distance class). In contrast, the genetic variation in the Lang Pan Hu (LPH) population (patch LPH-1) was found to be randomly distributed. The different spatial distribution patterns may be attributed to environment differences. These results have implications for the conservation and management of this species, especially for sampling strategies for ex situ conservation.  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