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1.
《Phytochemistry》1986,25(5):1175-1178
The roots of Gochnatia polymorpha afforded two new bisabolene derivatives and four dimeric guaianolides, two of them being isolated previously from G. paniculata. The aerial parts gave two further dimeric guaianolides. The aerial parts of G. hypoleuca afforded three new germacran-8,12-olides, a germacranolide acid and four additional dimeric guaianolides, which may be characteristic for this genus, while the presence of oxygenated germacranolides seems to be typical for the whole subtribe.  相似文献   

2.
The investigation of four South American species of the tribe Heliantheae afforded in addition to known compounds 14 new sesquiterpene lactones, mostly belonging to the melampolides, but four being further examples of cis,cis-germacranolides. The stereochemistry is established by intensive 1H-NMR studies and some chemical transformations. Some of the new lactones were only obtainable as inseparable mixtures of 2-methylbutyric and isovaleric esters. Furthermore a new acetylenic aldehyde was isolated. The chemotaxonomic situation is discussed especially with regard to the position of the genus Smallanthus.  相似文献   

3.
The investigation of four Helianthus species afforded, in addition to known compounds, four new atisirenic acid derivatives, a new ent-kaurenic acid derivative, three new labdane derivatives and an unknown C15-acetylenic compound. The structures of the diterpenes were elucidated by intensive NMR studies and some chemical transformations. An unusual fragmentation in the mass spectra of the atisirenes is discussed briefly.  相似文献   

4.
The investigation of five Trichogonia species afforded seven new furanoheliangolides, three dilactones of a new type, four pairs of epimeric rearra  相似文献   

5.
《Phytochemistry》1987,26(8):2321-2324
The aerial parts ofSenecio lividus afforded four triesters of shikimic acid, four eremophilanes and two bisabolene epoxides. The roots ofS.pyrenaicus ssp.caespitosus gave a known furoeremophilane while the aerial parts afforded a new one with a rare substitution pattern.S.doronicum contained known furoeremophilanes. The structures were elucidated by various high field NMR techniques.  相似文献   

6.
《Phytochemistry》1987,26(9):2597-2601
The investigation of four Brachylaena species afforded in addition to known sesquiterpene lactones four new guaianolide glucopyranosides and three further derivatives of salonitenolide. The chemotaxonomic relevance of these findings is discussed briefly.  相似文献   

7.
Paul A. Fryxell 《Brittonia》1980,32(2):262-268
Preliminary studies toward a treatment of the Malvaceae of Mexico have led to the discovery of four new taxa ofAbutilon and two new combinations inAllowissadula. In addition, a new Brazilian species ofPavonia is described.  相似文献   

8.
The investigation of twelve further species of the Eupatorium complex affords four new germacrolides and seven guaianolides together with new thymol and p-hydroxyacetophenone derivatives. The structures of these compounds have been elucidated by spectroscopic methods. Chemotaxonomic aspects of these findings are briefly discussed.  相似文献   

9.
Helichrysum natalitium afforded four new phloroglucinol derivatives, while from H. bellum two further compounds of this type have been isolated; H. platypterum yielded two known derivatives. The new structures were elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomical situation is briefly discussed.  相似文献   

10.
The aerial parts of Flourensia macrophylla afforded, in addition to compounds similar to those from other Flourensia species, four new eudesman  相似文献   

11.
SectionLinopsis of the genusLinum is the largest and probably the most widespread of the five commonly recognized sections. Using a number of traits, but especially heterostyly, style union, development of false septa in the fruit, pollen morphology, and chromosome number, together with petal pigmentation, number of floral parts, and stigma shape, the section is divided into five subsections:Dichrolinum, with one series;Halolinum with one;Linopsis, with four;Keniense, with one; andRigida, with two. Of these, subsect.Keniense and two series are new, the remaining four subsections and four series are published in a new rank. The inferred relationships of all of the groups and the general distribution of each are discussed. The section ranges from southern Europe and the Mediterranean region to India, eastern and southern Africa and throughout much of North and South America. The primitive species of the section are believed to be in the Mediterranean region.  相似文献   

12.
The investigation of two further Senecio species afforded two new furanoeremophilanes, four eremophilanolides and a new hydroxyeremophilane. The structures of two furanoeremophilane, isolated before, have been revised.  相似文献   

13.
The chloroform extract of the aerial parts of Mikania congesta, afforded four new geranylnerol derivatives, new analogs of deoxyelephantopin, a new melampolide and several known compounds. Structures were elucidated by spectroscopic methods and chemical transformations.  相似文献   

14.
15.
The isolation and structure determination of four known and eight new cis-clerodane lactones from the aerial parts of Solidago virgaurea are described.  相似文献   

16.
The genus Chrysacanthia Lacroix (Chrysopidae: Belonopterygini) is reviewed and a new species is described from Nigeria. With the addition of the new species described herein, the genus contains four Old World species known from Madagascar, Nigeria, India, Thailand and China.  相似文献   

17.
An investigation of the aerial parts of Dicoma tomentosa afforded four new germacranolides and four melampolides together with urospermal A and its 11β,13-dihydroderivative. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.  相似文献   

18.
《Phytochemistry》1986,26(1):201-204
The chloroform extract of the aerial parts of Gaillardia powellii afforded four known and four new helenanolides, the latter all oxygenated on C-15, as well as the flavones hispidulin and eupafolin.  相似文献   

19.
The airial parts of Podachaenium eminens contain, besides known compounds, four new guaianolides. The roots afford known acetylenes together with a new euparine-derivative. The structures are elucidated using spectroscopic methods.  相似文献   

20.
The investigation of several Brickellia species and two further related species afford besides known compounds four new labdane derivatives, a new acetylenic carbinol and a new dihydrobenzofuran derivative. The structures have been elucidated by spectroscopic methods. The chemotaxonomic aspects are discussed briefly.  相似文献   

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