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排序方式: 共有102条查询结果,搜索用时 15 毫秒
31.
描述了爵床科孩儿草属的一个新组-密花孩儿草组Rungia sect.Stoloniferoe C.M.Gao&Y.F.Deng。本新组花序不偏向一侧,苞片均能育,同形。 相似文献
32.
33.
A novel alkaloid and a galactoside isolated from the roots of Adhatoda vasica have been characterized as 9-acetamido-3,4-dihydropyrido-(3,4-b)-indole and O-ethyl-α-D-galactoside respectively by chemical and spectroscopic methods. In addition sitosterol β-D-glucoside, D-galactose and deoxyvasicinone have also been isolated from the roots of this plant. 相似文献
34.
A new iridoid glucoside, hygrophiloside, has been isolated from Hygrophila difformis. Hygrophiloside is apparently identical to the so-called ‘Cardanthera-Pseudoindican’. Its structure has been established by spectroscopic means and by reduction to isoaucubin. 相似文献
35.
报道中国爵床科一新记录种——翅柄裸柱草[Gymnostachyum sigantum (Benoist) J. B. Imlay],并提供了该种的描述。为名称Gymnostachyum sigantum指定了后选模式。 相似文献
36.
Two new 2'-oxygenated flavones, 5,7,2'-trimethoxyflavone (1). and 5,7,2',4',6'-pentamethoxyflavone (2). were isolated from the whole plant of Andrographis viscosula along with three known flavones, echioidinin (3). 5,2',6'-trihydroxy-7-methoxyflavone (4). and echioidin (5). The structures of these compounds were elucidated on the basis of 1D and 2D NMR spectral studies. 相似文献
37.
Three flavonoids, 5,7,2',3',4'-pentamethoxyflavone (1), 2'-hydroxy-2,4',6'-tri methoxychalcone (2) and dihydroskullcapflavone I (3), together with 17,19,20-trihydroxy-5beta, 8alpha H, 9beta H,10alpha-labd-13-en-16,15-olactone (4), a known diterpenoid and six known flavonoids, 5-hydroxy-7,8-dimethoxyflavanone (5), 5-hydroxy-7,8,2',3',4'-pentamethoxyflavone (6), 5,2'-dihydroxy-7-methoxyflavanone (7), 5,2'-dihydroxy-7,8-dimethoxyflavone (8), 5,2'-dihydroxy-7-methoxyflavone (9) and 5,2'-dihydroxy-7-methoxyflavone 2'-O-beta-D-glucopyranoside (10) were isolated from the whole plant of Andrographis lineata. The structures of these compounds were elucidated on the basis of spectral and chemical studies. 相似文献
38.
Antifungal diterpenes from Hypoestes serpens (Acanthaceae) 总被引:2,自引:0,他引:2
Rasoamiaranjanahary L Marston A Guilet D Schenk K Randimbivololona F Hostettmann K 《Phytochemistry》2003,62(3):333-337
Two new diterpenes, fusicoserpenol A and dolabeserpenoic acid A, with antifungal activity, were isolated from leaves of Hypoestes serpens (Acanthaceae). Their structures were elucidated by means of spectrometric methods including 1D and 2D NMR experiments and MS analysis. X-ray crystallographic analysis confirmed the structure of fusicoserpenol A and established the relative configuration. 相似文献
39.
Five 2,4,6-prenylated phloroglucinols, garcinielliptones HA (1), HB (2), HC (3), HD (4) and HE (5), were isolated from the heartwood of Garcinia subelliptica Merr. Their structures, including relative configurations, were elucidated by means of spectroscopic data analysis. The ability of phloroglucinols, 1-5 and lignans, tuberculatin (8), justicidin A (9), procumbenoside A (10) and ciliatosides A (11) and B (12), isolated from Justicia ciliata and Justicia procumbens, to induce DNA-cleavage activity was examined using pBR322, a supercoiled, covalently closed circular DNA, and it was analyzed by agarose gel electrophoresis. In the presence of Cu (II), compounds 3, 8, 10 and 11 caused significant breakage of supercoiled plasmid pBR322. The products were relaxed circles with no detectable linear forms. In the Cu(II)-mediated DNA damage of 3 and selective compound 8, Cu(I) was shown not to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine. 相似文献
40.
Sheila Regina Profice 《Brittonia》1997,49(1):67-70
Two new species, Mendoncia bahiensis and Mendoncia blanchetiana, of the subgenus Bremekampia are described and illustrated. A key to four species represented in Bahia and commentary on their taxonomic affinities are
provided. 相似文献