Flavonoid pattern and systematics of the genus Leucocyclus

The flavonoid pattern of the monotypic Turkish genus Leucocyclus consists of C-glycosylflavones (isovitexin; isoorientin and derivatives; several di-C-glycosylapigenins; schaftoside, isoschaftoside and vicenin-3; lucenin-2), of flavonol 3-O-glycosides (quercetin and kaempferol 3-O-rhamnoglucoside) and trace amounts of luteolin 7-O-rhamnoglucoside. The systematic significance of the flavonoid diversification within Leucocyclus as well as possible relationships to other genera of the Anthemideae are discussed.     

Comparative phytochemistry and systematics of Anacyclus

Leaf flavonoids of 13 Anacyclus taxa have been identified and compared. The most common compounds are 3-, 7- or 5-glycosylated flavonols which, together with the accumulation of 2 diosmetin 7-glycosides, help to delimitate species groups according to recent morphological and cytological findings. In addition to quercetagetin, quercetagetin 3'-methyl ether, patuletin and spinacetin have been isolated as 7-glucosides from the yellow disc and ray flowers of Anacyclus radiatus. The distribution patterns of polyacetylenes and particularly related amides, characterize different Anacyclus species and apparently contribute to a more natural interpretation of relationships with other genera, which may also be underlined by the distribution of cyanogenic glycosides.     

Flavonoids from Artemisia ludoviciana var. ludoviciana

Nineteen flavonoids were isolated from Artemisia ludoviciana var. ludoviciana, including a new 2′- hydroxy- 6-methoxyflavone, 5,7,2′,4′-tetrahydroxy-6,5′-dimethoxyflavone. The known compounds include quercetagetin 3,6,3′,4′-tetramethyl ether, eupatilin, 5,7-dihydroxy-3,6,8,4′-tetramethoxyflavone, luteolin 3′,4′-dimethyl ether, jaceosidin, 5,7,4′-trihydroxy-3,6-dimethoxyflavone, tricin, hispidulin, chrysoeriol, kaempferol 3-methyl ether, apigenin, axillarin, eupafolin, selagin and luteolin together with three flavones which were previously isolated for the first time from Artemisia frigida: 5,7,4′-trihydroxy-6, 3′,5′-trimethoxyflavone, 5,7,3′-trihydroxy-6,4′,5′-trimethoxyflavone and 5,7,3′,4′-tetrahydroxy-6,5′- dimethoxyflavone.     

Secondary metabolites from Ajania salicifolia and their chemotaxonomic significance

Forty-seven secondary metabolites were isolated from Ajania salicifolia (Mattf.) Poljak, including eight sesquiterpenoids, two diterpenoids, three triterpenoids, four steroids, three flavonoids, five coumarins, five lignans, nine phenylpropanoids, five other phenolic compounds, and three acetylenes. Their chemotaxonomic significance within the genus Ajania (the tribe Anthemideae) of the family Asteraceae is discussed.     

Sesquiterpene lactones and other constituents from Schistostephium species

From four Schistostephium species, in addition to known compounds, 43 new ones were isolated, three isocomene, two bisabolene, two eudesmane, two allo-himachalene and two nerolidol derivatives, two sesquiterpenes with a new carbon skeleton derived from isocomene, nine eudesmanolides, 20 6,12- and 8,12-germacranolides respectively, and a prostaglandin-like acid. The structures were elucidated by spectroscopic methods, especially high field ¹H NMR and some chemical transformations. The stereochemistry of some 8,12-germacranolides was established by partial synthesis which required revision of the previous assignments of the configuration of inunolide, its 4,5- and 1,10-epoxide, vernudifloride, simsiolide, 6-hydroxy-1,10-epoxyinunolide and perhaps also of tanachin. The chemotaxonomic situation is discussed briefly.     

Localization of 45S and 5S rDNA sites and karyotype of Chrysanthemum and its related genera by fluorescent in situ hybridization

The phylogenetic relationships among Chrysanthemum and its related genera (Anthemideae, Asteraceae) is poorly understood. In the present study, these relationships were investigated using 45S and 5S ribosomal DNA (rDNA)-targeted fluorescent in situ hybridization. The results showed that there were two 45S rDNA signals present in Crossostephium chinense, four 45S rDNA signals in Cercidiphyllum japonicum, Artemisia sieversiana, Artemisia annua and Artemisia absinthium, six 45S rDNA signals in Chrysanthemum boreale and Pyrethrum parthenium, eight 45S rDNA signals in Chrysanthemum nankingense, Chrysanthemum dichrum, Chrysanthemum lavandulifolium and Tanacetum vulgare, and ten 45S rDNA signals in Ajania przewalskii. For the 5S rDNA locus, two 5S rDNA signals were present in C. nankingense, C. dichrum, C. lavandulifolium, C. boreale, C. japonicum, C. chinense and P. parthenium, four in A. sieversiana, A. annua, A. absinthium and A. przewalskii, and six 5S in T. vulgare. In addition, karyotypes of the 12 species were investigated. From this study, we inferred that Chrysanthemum was closely related to Ajania, and that Chrysanthemum species originating from China and Japan may have evolved differently. These findings add a new level to the understanding of the phylogenetic relationships of Chrysanthemum and related genera.     

The Genus Artemisia and its Allies: Phylogeny of the Subtribe Artemisiinae (Asteraceae, Anthemideae) Based on Nucleotide Sequences of Nuclear Ribosomal DNA Internal Transcribed Spacers (ITS)

Abstract: Sequences of the internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA were analysed for 44 Artemisia species (46 populations) representing all the five classical subgenera and the geographical range of the genus, 11 species from 10 genera closely related to Artemisia, and six outgroup species from five other genera of the Anthemideae. The results definitely support the monophyly of the genus Artemisia in its broadest sense (including some taxa segregated as independent genera, like Oligosporus and Seriphidium ). Eight main clades are established in this molecular phylogeny within Artemisia; they agree in part with the classical subdivision of the genus, but they also suggest that some infrageneric groups must be redefined, especially the subgenus Artemisia. The subgenera Tridentatae and Seriphidium are independent from each other. Some of the satellite genera are clearly placed within Artemisia ( Artemisiastrum, Filifolium, Mausolea, Picrothamnus, Sphaeromeria, Turaniphytum ), whereas some others fall outside the large clade formed by this genus (Brachanthemum, Elachanthemum, Hippolytia, Kaschgaria). Our results, correlated to other data such as pollen morphology, allow us to conclude that the subtribe Artemisiinae as currently defined is a very heterogeneous group. Affinities of the largest genus of the subtribe and tribe, Artemisia, and of other genera of the subtribe to some genera from other subtribes of the Anthemideae strongly suggest that subtribe Artemisiinae needs a deep revision and redefinition. Phylogenetic utility of region trnL-F of the plastid DNA in the genus Artemisia and allies was also evaluated: sequences of the trnL-F region in Artemisia do not provide phylogenetic information.