Bibenzyls and dihydroisocoumarins from white salsify (Tragopogon porrifolius subsp. porrifolius)

A phytochemical investigation of three accessions of Tragopogon porrifolius L. subsp. porrifolius (Asteraceae, Lactuceae) yielded three new bibenzyl derivatives, 5,4'-dihydroxy-3-alpha-l-rhamnopyranosyl-(1-->3)-beta-d-xylopyranosyloxybibenzyl, 2-carboxyl-3,4'-dihydroxy-5-beta-d-xylopyranosyloxybibenzyl, tragopogonic acid (2'carboxyl-3',5',4'-trihydroxyphenylethanone) and three dihydroisocoumarin derivatives, including the new natural product 6-O-methylscorzocreticoside I. One of the isolated bibenzyl derivatives is considered to be a precursor to the biosynthesis of dihydroisocoumarins. Structures of new compounds were established by HR mass spectrometry, extensive 1D and 2D NMR spectroscopy, and CD spectroscopy. Moreover, radical scavenging activities of the polyphenolic compounds were measured using the 2,2-diphenyl-1-picrylhydrazyl assay; two of the bibenzyls showed moderate and two of the dihydroisocoumarins showed weak radical scavenging activities. The chemosystematic impact of bibenzyls and dihydroisocoumarins is discussed briefly.     

Historic Anthropogenically Maintained Bear Grass Savannas of the Southeastern Olympic Peninsula

This paper documents the existence and character of a little known fire‐maintained anthropogenic ecosystem in the southeastern Olympic Peninsula of Washington State, U.S.A. Due to cessation of anthropogenic burning, there is no longer an intact example of this ecosystem. We present evidence from Skokomish oral tradition, historical documents, floral composition, tree‐ring analysis, stand structure, and site potential to describe former savanna structure and function. We believe this system was a mosaic of prairies, savannas, and woodlands in a forest matrix maintained through repeated burning to provide culturally important plants and animals. The overstory was dominated by Douglas‐fir (Pseudotsuga menziesii). Bear grass (Xerophyllum tenax) likely was a dominant understory component of the savannas, woodlands, and prairie edges. These lands grew forests in the absence of anthropogenic burning. Wide spacing of older trees or stumps in former stands and rapid invasion by younger trees in the late 1800s and early 1900s suggest a sudden change in stand structure. Shade‐intolerant prairie species are still present where openings have been maintained but not in surrounding forests. Bark charcoal, fire scars, tree establishment patterns, and oral traditions point to use of fire to maintain this system. A common successional trajectory for all these lands leads to forested vegetation. These findings suggest that frequent application of prescribed burning would be necessary to restore this ecosystem.     

芸苔族几种植物花粉形态的研究

对芸苔族８种２变种的花粉进行了光镜和扫描电镜观察。其中４种２变种为首次报道。研究表明,芸苔族植物花粉形态特征基本一致。但在花粉大小、萌发孔类型以及外壁纹饰上种间存在一定的差异。同时发现该族植物的花粉大小与其染色体数有一定的相关性。     

缘蝽科的比较形态学研究Ⅲ（异翅亚目：缘蝽总科）

缘蝽科的比较形态学研究　Ⅲ（异翅亚目：缘蝽总科）李新正（中国科学院海洋研究所青岛２６６０７１）１５棒缘蝽亚科（Ｐｓｅｕｄｏｐｈｌｏｅｉｎａｅ）（图６８—８３）棒缘蝽类包括２８个属,除ＶｉｌｇａＳｔａｌ为新世界分布,ＣｅｒａｌｅｐｔｕｓＣｏｓｔａ和颗缘...     

十字花科芸薹族植物叶脉序的研究

对中国十字花科芸薹族6属9种植物进行叶片脉序的比较观察,结果表明:脉序可分为两大类型:Ⅰ.分枝曲行羽状脉,如芸薹属、芝麻菜属和两节荠属;Ⅱ.环结曲行羽状脉,如萝卜属、诸葛菜属和线果芥属。从脉序上看,芸薹属与两节荠属和芝麻菜属的亲缘关系比和萝卜属、诸葛菜属、线果芥属近。此外,芸薹属植物的脉序,依据二级间脉可将其分为两种亚类型:Ⅰ.简单型,如羽衣甘蓝;Ⅱ.复合型,如芸薹、青菜和芥菜,由此认为在芸薹属中羽衣甘蓝是比较原始的种类。     

鲤科鱼类前方椎体的形成及其在系统发育上的意义

本文对九种鲤科鱼类与中国胭脂鱼幼体的前方椎体的发育进行了比较。观察结果表明这两个科鱼类的前方椎体发育是近似的,它们的魏氏小骨有共同的来源;魏氏复合骨由前方椎体上方的第二骨化中心形成,这个骨化中心与第三和第四上神经骨相当。另一方面,胭脂鱼幼体的第二椎体副突已与第四椎体的胸肋相接;魏氏复合骨的扩展是骨化中心背脊部均匀地发生的,这些与鲤科有着明显的不同。鲤科幼体的魏氏复合骨发育具有共同的特点,第二骨化中心的前方有一棘状物在早期出现,它代表了第三上神经骨伸出部份。但随后的发育可以区分为两种不同方式:一种为雅罗系鱼类所具有,即第二骨化中心以棘状物的扩展为主,前、后棘存在并有缝合线相连;另一种为鲃系鱼类所有,即第二骨化中心的发育以其背中部伸出的实心嵴突为主,仅有不发达的前棘,此系属于派生性结构。与魏氏复合骨相关的是2—3椎体间的关系也有相应的差别:雅罗系鱼类的幼体其2—3椎体间分离(仅鳑(鱼皮)亚科鱼类例外),而鲃系鱼类的幼体其2—3椎体愈合。由于幼体魏氏复合骨与椎体的特征比成体表现更为明显,它们在系统发育上能提供更为清楚的信息。     

Bicoronal synostosis in a child from historic Omaha Cemetery 25DK10

Fragmentary cranial remains of a child from a commingled burial in a historic Omaha Cemetery (AD 1780–1800) exhibit bony fusion between the frontal, parietals, and sphenoid. The child's remains are consistent with a developmental age between newborn and 6 months postnatal. Radiological and morphological analyses confirm that this individual exhibits osteological signs pathognomic of bicoronal sutural synostosis, including deformation of the lateral orbital margin. This case, although fragmentary, significantly augments other archaeological cases of coronal synostosis reported in the literature. In addition, an extremely large bregmatic fontanel, expanded anterior cranial fossa, and bossed forehead compared with undeformed individuals suggest the child also suffered from increased intracranial pressure perhaps related to an associated hydrocephaly. Despite the deformity, the remains of this child were treated in much the same manner as other infant remains from the site, including the presence of red mercury pigment on the skeletal remains. Am J Phys Anthropol 105:369–376, 1998. © 1998 Wiley-Liss, Inc.     

Stilbenoids from Tragopogon orientalis

A phytochemical investigation of Tragopogon orientalis L. (Asteraceae, Cichorieae) yielded the natural products 6'-O-(7,8-dihydrocaffeoyl)-alpha,beta-dihydrorhaponticin, 3'-O-methyl-alpha,beta-dihydrorhaponticin, and (S)-3-(4-beta-glucopyranosyloxybenzyl)-7-hydroxy-5-methoxyphtalide as well as known compounds alpha,beta-dihydrorhaponticin, 3-(4-methoxybenzyl)-5,7-dimethoxyphthalide, p-dihydrocoumaric acid methyl ester, and 1-hydroxypinoresinol-1-O-beta-glucopyranoside. The structures were established by HR mass spectrometry, extensive 1D and 2D NMR spectroscopy, and CD spectroscopy. Moreover, the radical scavenging activities of the major compounds were measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The chemosystematic impact of the occurrence of stilbene derivatives in T. orientalis is discussed.     

中国唇形科草糙苏属分类学研究杂记(英文)

最近的研究结果表明,国产糙苏属(Phlomis)的所有种类(除了栽培种橙花糙苏P.fruticosa以外)以及沙穗属(Eremostachys)、独一味属(Lamiphlomis)、钩萼草属(Notochaete)均应并入草糙苏属(Phlomoides)。新界定的草糙苏属因其草本习性等特征而与糙苏属易于区别。尽管已有不同作者对国产草糙苏属大部分物种名称进行了新组合,但仍遗漏了11个物种名称。为方便使用,本文对这11个名称进行了新组合,同时提供了新界定的草糙苏属国产物种名录及检索表,共50种9变种。