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21.
The sesquiterpene lactones isolated from species in the genus Artemisia have been reviewed in an attempt to better understand the phylogeny and systematics of the four sections (subgenera), Abrotanum, Absinthium, Dracunculus and Seriphidium, proposed by Besser in 1829. The absence of hair on the receptacle is the only morphological characteristic separating species of Abrotanum from the species of Absinthium. There are no chemical characteristics segregating the species in these two subgenera since both produce eudesmanolides and guaianolides that are identical or biosynthetically similar. This suggests that the two subgenera could be combined into one (Artemisia) as proposed by Poljakov. The subgenus Seriphidium is composed of two geographical groups, one in the Old World and the other in the New World. The Old World species almost exclusively produce sesquiterpene lactones in the eudesmanolide class whereas the New World species (section Tridentatae) produce eudesmanolides and guaianolides, many of the latter being identical or structurally related to the sesquiterpene lactones in New World Abrotanum species. The chemical data in conjunction with geographic distributions suggest that the subgenus Seriphidium is polyphyletic and that the section Tridentatae originated from Abrotanum. Consequently, the Tridentate should be recognized as a subgenus separate and distinct from the Old World Seriphidium. There was insufficient information from the subgenus Dracunculus for interpretation. 相似文献
22.
Ferdinand Bohlmann Pradip K. Mahanta Arvind A. Natu Robert M. King Harold Robinson 《Phytochemistry》1978,17(3):471-474
The investigation of two Isocarpha species has yielded eight new germacranolides most of them belonging to the heliangolides. In addition to known p-hydroxyacetophenone-derivatives, a new dihydroeuparine derivative was isolated. The chemotaxonomical aspects are discussed. 相似文献
23.
From three Mikania species, three new labdanic acid and two kaurenic acid derivatives have been isolated together with known compounds and four new germacranolides, differing only in the ester moiety. 相似文献
24.
Ferdinand Bohlmann 《Phytochemistry》1978,17(2):319-320
25.
An Australian member of the tribe Senecioneae, Bedfordia salicina, contains besides known compounds new dimeric eremophilenolides, new kolevane derivatives, a kaurenic acid and several further sesquiterpenes, most of them related to xanthatine. The structures are elucidated mainly by spectroscopic methods and by some chemical transformations. The chemotaxonomic aspects of these findings are discussed briefly. 相似文献
26.
Ferdinand Bohlmann Lutz Müller Rajinder K. Gupta Robert M. King Harold Robinson 《Phytochemistry》1981,20(9):2233-2237
Out of the nineteen species of Vernonia studied, five contained highly oxygenated sesquiterpene lactones, while the rest contained predominantly triterpenes, especially lupane derivatives. 相似文献
27.
Ferdinand Bohlmann Autar K. Dhar Jasmin Jakupovic Robert M. King Harold Robinson 《Phytochemistry》1981,20(5):1077-1080
The investigation of D. halimifolia afrorded a new glaucolide and two sesquiterpene lactones with an additional propiolactone ring, one elemanolide and one modified germacranolide with an additional ring. Furthermore, two tremetone derivatives were present, a hydroxy-geranylgeraniol, also present in a Kingianthus species, and several known compounds. 相似文献
28.
Mitsumasa Haruna Makiko Kato Kazuo Ito Toshiaki Nikai Hisayoshi Sugihara Hiroyuki Muratat 《Phytochemistry》1981,20(11):2583-2584
Angeloylcumambrin-B, a new antimicrobial guaianolide sesquiterpene lactone, was isolated from Chrysanthemum ornatum and the structure was determined by a combination of chemical and physical methods. 相似文献
29.
Ferdinand Bohlmann Jürgen Ziesche Robert M. King Harold Robinson 《Phytochemistry》1981,20(6):1335-1338
The investigation of Dimerostemma asperatum afforded four new eudesmanolides, two unusual acetylenic esters and two diterpene lactones related to g 相似文献
30.
The reinvestigation of the aerial parts of Wedelia trilobata afforded, in addition to known compounds, six new eudesmanolides, two ent-kaurenic acid derivatives as well as a degraded one. A corresponding hydroxy compound was present in Gnaphalium undulatum. From Aspilia parvifolia new ent-kaurenic acid epoxides were isolated. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly. 相似文献