共查询到20条相似文献,搜索用时 15 毫秒
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The isolation of a new diterpene lactone and two known diterpenoid acids from the aerial parts of Viguiera maculata is reported. 相似文献
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One new furanoheliangolide derivative, 4,5-dihydroniveusin A, as well as the known compounds niveusin B and argophyllin A and B, were isolated from a Texas population of Helianthus annuus. Three previously characterized diterpene acids, grandifloric acid, ciliaric acid and 17-hydroxy-ent-isokaur-15(16)-en-19-oic acid were the principal constituents of this population. 相似文献
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Laurencia obtusa collected at Kimmeridge Bay, Dorset contained 15-bromo-2,16-diacetoxy-7-hydroxy-9(11)-paraguarene as a major metabolise. Closely related compounds have recently been isolated from the sea hare Aplysia dactylomela collected at La Parguera, Puerto Rico. 相似文献
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Agelo C. Pinto Maria L. Patitucci Dorothea H.T. Zocher Alphonse Kelecom 《Phytochemistry》1985,24(10):2345-2347
The absolute configurations of four cleistanthane diterpenes isolated from several species of Vellozia were determined by circular dichroism measurements. 相似文献
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Castelo-Branco PA dos Santos FJ Rubinger MM Ferreira-Alves DL Piló-Veloso D King-Díaz B Lotina-Hennsen B 《Zeitschrift für Naturforschung. C, Journal of biosciences》2008,63(3-4):251-259
Nine diterpene lactone amide derivatives 1-9 were synthesized from 6-oxovouacapan-7beta,17beta-lactone, which was obtained from 6alpha,7beta-dihydroxyvouacapan-17beta-oic acid isolated from Pterodon polygalaeflorus Benth., and tested for their activity on photosynthetic electron transport. Amide derivatives 3-5 behaved as electron transport chain inhibitors; they inhibited the photophosphorylation and uncoupled non-cyclic electron transport from water to methylviologen (MV). Furthermore, 4 and 5 enhanced the basal electron rate acting as uncouplers. Compound 6 behaved as an uncoupler; it enhanced the light-activated Mg2+-ATPase and basal electron flow, without affecting the uncoupled non-cyclic electron transport. Compounds 1-2 and 7-9 were less active or inactive. Compounds 3-5 did not affect photosystem I (PSI); they inhibited photosystem II (PSII) from water to 2,6-dichlorophenol indophenol (DCPIP). Compound 4 inhibited PSII from water to silicomolybdate (SiMo), but it had no effect on the reaction from diphenylcarbazide (DPC) to DCPIP indicating that its inhibition site was at the water splitting enzyme complex (OEC). Compounds 3 and 5 inhibited PSII from water to DCPIP without any effect from water to SiMo, therefore they inhibited the acceptor site of PSII. Chlorophyll a fluorescence kinetics confirmed the behaviour of 3-5. 相似文献
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An extract of the aerial parts from Alomia myriadenia Schultz-Bip. ex Baker (Asteraceae) showed significant cytotoxicity against a panel of human cancer cell lines in a screening of extracts from Brazilian Atlantic Forest plant species. Employing a bioassay-linked HPLC-electrospray/MS method, followed by semi-preparative HPLC, the active component was isolated and characterized as a mixture of epimers of the labdane diterpene 12S,16-dihydroxy-ent-labda-7,13-dien-15,16-olide. 相似文献
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A new isopimarane diterpenoid, isoakhdartriol, was isolated in very small amount from the aerial part of Amaracus akhdarensis. Its structure, isopimar-15-en-3β,8β,19-triol, was established by spectroscopic means. 相似文献
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Sonderianol (12-hydroxy-3-oxo-cleistanth-8, 11, 13, 15-tetraene) and 3, 4-seco-sonderianol (methyl 12-hydroxy-3, 4-seco-cleistanth-8, 11, 13, 15, 18(4)-penten-3-oate), two new diterpenes with cleistanthane skeletons, were isolated from heartwood of Croton sonderianus. 相似文献
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Angelo C. Pinto Paul M. Baker Benjamin Gilbert Richard Pinchin Francisco A.M. Reis Magda S. Waineraich Dorothea H.T. Zocher 《Phytochemistry》1980,19(11):2486-2487
The isolation of (20R)-20-hydroxy-24-methylenedammar-3-one from Vellozia stipitata is described. 相似文献
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From the anticancer-active CHCl3, extract of the plant Euphorbia maddeni, a polyacylated diterpene of jatrophone type, euphornin, has been isolated and its structure elucidated by physico-chemical methods. 相似文献
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Clive W. Ford 《Phytochemistry》1981,20(8):2019-2020
The isolation of a new lactone, 2-methyl-2,3,4-trihydroxybutanoic acid-1,4-lactone, from leaves of water-stressed chickpea is described. Elucidation of the structure was by chemical and spectroscopic methods. The lactone could not be detected in the leaves of well-watered plants. Its occurrence in other species is confirmed. 相似文献
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Four known isoprenoids were isolated from Lemna minor besides a novel diterpene which was attributed the structure (4R)-4-hydroxyisophytol by spectroscopic studies and chemical correlation. 相似文献
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Marden A. de Alvarenga Hugo E. Gottlieb Otto R. Gottlieb Mauro T. Magalhães Vanderlan O. da Silva 《Phytochemistry》1978,17(10):1773-1776
The trunkwood of Croton diasii Pires (Euphorbiaceae) contains diasin, a novel rearranged labdanic diterpene which includes furan, carbomethoxy, γ 相似文献
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The new clerodane diterpene 1 was isolated from the aerial parts of Baccharis tucumanensis (Compositae). Its structure has been determined from spectral data combined with chemical transformations. 相似文献
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From Helichrysum refluxum, in addition to known compounds, a diterpene acid related to erythroxydiol Z was isolated. The structure was elucidated by NMR techniques. 相似文献