Seven germacranolides, eupaglehnins A, B, C, D, E, and F, and 2alpha-acetoxyepitulipinolide from Eupatorium glehni.
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Four new germacrane-type sesquiterpenoids with unsaturated acids as esters at the 8-position, two chlorine atom-containing lactones, 2alpha-acetoxyepitulipinolide, and 12 previously known compounds have been isolated from the MeOH extract of Eupatorium glehni (Compositae) and their structures have been determined on the basis of spectral data analyses. (+info)
Polyphyletic origin of pyrrolizidine alkaloids within the Asteraceae. Evidence from differential tissue expression of homospermidine synthase.
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The evolution of pathways within plant secondary metabolism has been studied by using the pyrrolizidine alkaloids (PAs) as a model system. PAs are constitutively produced by plants as a defense against herbivores. The occurrence of PAs is restricted to certain unrelated families within the angiosperms. Homospermidine synthase (HSS), the first specific enzyme in the biosynthesis of the necine base moiety of PAs, was originally recruited from deoxyhypusine synthase, an enzyme involved in the posttranslational activation of the eukaryotic initiation factor 5A. Recently, this gene recruitment has been shown to have occurred several times independently within the angiosperms and even twice within the Asteraceae. Here, we demonstrate that, within these two PA-producing tribes of the Asteraceae, namely Senecioneae and Eupatorieae, HSS is expressed differently despite catalyzing the same step in PA biosynthesis. Within Eupatorium cannabinum, HSS is expressed uniformly in all cells of the root cortex parenchyma, but not within the endodermis and exodermis. Within Senecio vernalis, HSS expression has been previously identified in groups of specialized cells of the endodermis and the adjacent root cortex parenchyma. This expression pattern was confirmed for Senecio jacobaea as well. Furthermore, the expression of HSS in E. cannabinum is dependent on the development of the plant, suggesting a close linkage to plant growth. (+info)
Trypanocidal and leishmanicidal activities of flavonoids from Argentine medicinal plants.
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In vitro trypanocidal and leishmanicidal activities of the flavonoids hispidulin, from Ambrosia tenuifolia, and santin, from Eupatorium buniifolium, are reported. A sensitive technique that takes advantage of ((3)H)thymidine uptake by dividing trypanosomatids has been adjusted for quantification of the parasiticidal effect of the natural products. The IC(50) values for hispidulin and santin on Trypanosoma cruzi epimastigotes were 46.7 and 47.4 muM, respectively. On trypomastigotes, the IC(50) values were 62.3 microM for hispidulin and 42.1 microM for santin. Hispidulin was more active than santin on promastigotes of Leishmania mexicana (IC(50) = 6.0 microM versus 32.5 microM). No cytotoxic activity was observed on lymphoid cells, making hispidulin and santin potential lead compounds for the development of new natural drugs. This is the first report on the trypanocidal and leishmanicidal activities of these flavonoids and on the presence of santin in E. buniifolium. (+info)
Sesquiterpenoids isolated from Eupatorium glehnii. Isolation of guaiaglehnin A, structure revision of Hiyodorilactone B, and genetic comparison.
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A new sesquiterpenoid substituted with unsaturated ester, guaiaglehnin A (1), along with 15 previously known compounds, were isolated from the methanol extract of the terrestrial part of Eupatorium glehnii (Compositae) collected in Nagano Prefecture, Japan, the results of which supported the previous study by Takahashi et al. The chemical constituents of E. glehnii collected in Nagano Prefecture and those collected in Tokushima or Hokkaido are quite different, depending on collection site, although the species are identical. The base sequences of three different samples were identical. Diversity in the chemical components was detected, though no diversity existed in the DNA sequence. In this study, eupasimplicin A (2) was also isolated, whose presence in the extract of E. chinense simplicifolium was recorded but not in an article. The side chain geometry of hiyodorilactone B (5) was revised to be E. (+info)
Caffeic acid derivatives from Eupatorium perfoliatum L.
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Tetracladium nainitalense sp. nov., a root endophyte from Kumaun Himalaya, India.
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An aquatic hyphomycete, Tetracladium nainitalense sp. nov., isolated as a root endophyte from riparian plants from Nainital, Kumaun Himalaya, India, is illustrated and described. The new species is characterized by laterally applanate conidia appearing lobate, with typically four rounded apices and lacking filiform, acicular or subulate elements. An updated key to the species of Tetracladium is provided. (+info)
HSP70 inducers from Chinese herbs and their effect on melanin production.
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