雷公藤化学成分的研究

研究雷公藤(Tripterygium wilfordii Hook．f．)根心部分的化学成分。采用硅胶柱色谱法进行分离,从其氯仿提取物中分得五个化合物,经波谱分析化合物分别鉴定为：5α-stigmastane-3β,6α-diol(1)、epigallocatechin(2)、2,5-二甲氧基苯醌(3)、琥珀酸(4)和卫矛碱(5)。化合物1—4均为首次从该植物中分离得到。     

Three new oxygenated triterpenoids of the lupane series from Gymnosporia wallichiana

Two new epimeric triterpenoid acids, gymnosporic acid, 3β-hydroxy-(20R)-lupan-29-oic acid, wallichianic acid, 3β-hydroxy-(20S)-lupan-29-oic acid and a new diol wallichianol, (20S)-lupane-3β,29-diol have been isolated from Gymnosporia wallichiana, in addition to β-amyrin, friedelin, 3β-hydroxy-29-norlupan-20-one and dulcitol.     

Leaf colleters in Tontelea micrantha (Celastraceae,Salacioideae): Ecological,morphological and structural aspects

The colleter secretion can be useful to protect plants of Cerrado (Brazilian savanna) biome during the long and pronounced dry season. This study describes the presence of colleters in Tontelea micrantha and represents the first record of these structures in Celastraceae. To investigate colleter structure and their secretory processes, young leaves were collected, fixed, and processed according to conventional techniques for light, and electron microscopy. Colleters were observed at the marginal teeth on the leaf. They produce mucilaginous secretions that spread over the leaf surface. After secretory phase, colleters abscise. The secretory epithelium is uniseriate and composed of elongated cells whose dense cytoplasm is rich in organelles. The ultrastructure of the secretory cells is compatible with the pectin-rich secretion. Observations of the young leaves surface revealed the presence of superficial hydrophilic secretion films that appeared to have the function of maintaining the water status of those organs.     

Animal‐mediated long‐distance dispersals and migrations shaping the intercontinental disjunctions of Celastrus (Celastraceae) among five continents

The mechanisms underlying the origin, evolution, and distributional patterns of organisms are a major focus of biogeography. Vicariance and long‐distance dispersal (LDD) are two important explanations for disjunctive distribution patterns among lineages. In‐depth biogeographic studies of taxa that exhibit wide‐ranging disjunctions can provide valuable information for addressing the relative importance of these biogeographic mechanisms. The genus Celastrus contains ca. 30 species that are disjunctly distributed in five continents of both the Northern and Southern Hemispheres, providing an excellent system for historical biogeographic analyses. Here, we used sequence data from five markers (nuclear external transcribed spacer and internal transcribed spacer, and plastid psbA‐trnH, rpl16, and trnL‐F) to reconstruct the phylogeny of Celastrus and investigate its phylogenetic relationships with Tripterygium, estimate clade divergence times using the fossil‐calibrated method, and infer its ancestral distribution range. Celastrus and Tripterygium were each supported as monophyletic. The morphology‐based classification systems were not supported by the phylogenetic results. The divergence time between Celastrus and Tripterygium was estimated to be 26.22 Ma (95% highest posterior density: 24.46–28.17 Ma), and the diversification of Celastrus were suggested to be linked to global warming events during the Miocene. Celastrus was suggested to have a tropical Asian origin, and dispersed to Central and South America, North America, Oceania, and Madagascar at different periods, most probably through LDD. Birds may have facilitated transoceanic migrations of Celastrus because of its bicolored fruits, which contain red and fleshy arils. Our results highlight the importance of key morphological innovations and animal‐mediated dispersals for the rapid diversification of plant lineages across vast distributional ranges.     

Structures of elaeodendrosides B,C, F,G, K and L,a series of cardiac glycosides isolated from Elaeodendron glaucum

Six cardiac glycosides having an unusual sugar linkage, elaeodendrosides B, C, F, G, K and L, were isolated from seeds of Elaeodendron glaucum. These were characterized on the basis of the physical data and the results obtained by improved procedures for cleavage of their glycoside linkage.     

Flavonoids from Elaeodendron balae root bark

The root bark of Elaeodendron balae afforded ourateacatechin, ouratea-proanthocyanidin A and a new leucoanthocyanidin derivative elaeocyanidin.     

Sesquiterpene polyol esters from Celastrus rosthornianus

Two new sesquiterpene polyol esters with β-dihydroagarofuran skeleton were isolated from the root bark of Celastrus rosthornianus. Their structures were elucidated, mainly on the basis of spectral analyses, as 1 β-acetoxy-8β,9-dibenzoyloxy-6-hydroxy-2β(-methylbutanoyloxy)-β-dihydroagarofuran and 1β-acetoxy-9-benzoyloxy-8β-(β-furanocarbonyloxy)-6-hydroxy-2β(-methylbutanoyloxy)-β-dihydroagarofuran. The complete assignments of ¹³C NMR chemical shifts for both compounds on the basis of ¹H-¹³C chemical-shift correlation spectrum were also carried out.     

卫矛科16种藤本与乔木次生木质部比较解剖学研究

本文对卫矛科(Celastraceae)16种生长于不同生境的藤本和乔木次生木质部的结构,进行比较解剖学的观察,比较它们之间的异同。本科中南蛇藤属(Celastrus L.)独子藤属(Mo-nocelastrus Wang et Tang)和雷公藤属(Tripterygium Hoook.f.)为典型藤本结构,次生木质部特化水平较高;假卫矛属(Microstropis Wall.et Mcissn)、十齿花属(Dipentoden Dunn)和盾柱属(Pleurostylia Wight.et Arn.)为乔木,次生木质部结构特化水平较低;卫矛属(Eu-onymus L.)中既有藤本,又有乔木,其藤本结构与乔木相似,表现出一系列原始性和保守性。本研究初步探讨藤本与乔木的木质部结构、生活习性与生境之间的关系,为进一步研究卫矛科的系统演化提供一些解剖学的证据。     

Iguesterin,a new quinonoid triterpene from Catha cassinoides

β-Amyrin, sitosterol, celastrol, pristimerin, tingenone and a new hydroxymethylene quinonoid dinor-triterpene iguesterine were isolated from the root bark of Catha cassinoides. The structure of iguesterine was determined spectroscopically and by synthesis from tingenone. Tentative assignments are given for the chemical shifts of the methyl groups of iguesterin, tingenone and some of their derivatives.