排序方式: 共有65条查询结果,搜索用时 15 毫秒
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Zehong Wan Dramane I. Laine Hongxing Yan Chongjie Zhu Katherine L. Widdowson Peter T. Buckley Miriam Burman James J. Foley Henry M. Sarau Dulcie B. Schmidt Edward F. Webb Kristen E. Belmonte Michael Palovich 《Bioorganic & medicinal chemistry letters》2009,19(16):4560-4562
Design and syntheses of a novel series of muscarinic antagonists are reported. These efforts have culminated in the discovery of (3-endo)-3-(2-cyano-2,2-diphenylethyl)-8,8-dimethyl-8-azoniabicyclo[3.2.1]octane bromide (4a) as a potent and pan-active muscarinic antagonist as well as a functionally active compound in a murine model of bronchoconstriction. The compound has also displayed pharmacokinetic characteristics suitable for inhaled delivery. 相似文献
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The limonoid derivative, methyl uguenenoate, the azole, uguenenazole, and the amide, uguenenonamide, together with the known furoquinoline alkaloids flindersiamine and maculosidine, and syringaldehyde have been isolated from the root of the East African Rutaceae Vepris uguenensis. While methyl uguenenoate and the furoquinoline alkaloids displayed mild antimalarial activity, the azole and amide were completely inactive. 相似文献
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Toddaliopsins A-D, four novel 1,2,3-trioxygenated acridone alkaloids, have been isolated from the leaves of Toddaliopsis bremekampii. Toddaliopsins B-D are the first reported acridone alkaloids with substituted N-methyl groups, in the light of which the chemotaxonomic relationship of Toddaliopsis and Vepris is discussed. Toddaliopsin C possesses moderate anti-inflammatory activity, which may be related to the hydroxy group present at C-1. 相似文献
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The methanol extract of the seeds of Turraea parvifolia has yielded seven novel triterpenoid derivatives: 12alpha-acetoxyazadironolide, turraparvin A (12alpha-acetoxy-7alpha,23-dihydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,14,20(22)-trien-21,23-olide), turraparvin B (12alpha-acetoxy-7alpha,21-dihydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,14,20(22)-trien-23,21-olide), turraparvin C (7alpha,12alpha-diacetoxy-21-hydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,14,20(22)-trien-23,21-olide), 11-epi-21-hydroxytoonacilide, 11-epi-23-hydroxytoonacilide and turraparvin D (12alpha-acetoxy-7alpha-hydroxy-24,25,26,27-tetranor-3-oxoapotirucalla-1,14,20(22)-trien-21,23-lactam). 相似文献
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Six novel limonoids and limonoid derivatives, turraflorins D-I along with the known turraflorins A and B have been isolated from seed of the South African Turraea floribunda (Meliaceae). 相似文献
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The bufadienolides, rubellin and riparianin were isolated from the bulbs of Drimia macrocentra and Urginea riparia (Hyacinthaceae) respectively. Rubellin and riparianin contain a carbohydrate moiety doubly linked to the bufadienolide aglycone at the C-2 and C-3 positions. Riparianin showed moderate activity when tested against MCF7 (breast), TK10 (renal) and UACC62 (melanoma) cell lines. 相似文献
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The temporal dynamics of foraging, diet, and use of space is essential to understand the ecology of harvester ants. Here, we present an account of the foraging ecology of Pogonomyrmex naegelii in Brazilian cerrado savanna. Nests occur on bare ground and contain 166?C580 workers (N?=?3 colonies). Colony activity is unimodal year-round and peaks around the middle of the day. Foragers leave the nest independently and individually search for food in all directions. Ants ventured up to 15?m from nests, with most foraging occurring within 2?m of nests. Colonies tended to have larger home ranges in the dry/cold (April?CSeptember) than in the wet/warm season (October?CMarch). P. naegelii has a generalist and season-dependent diet comprised of many seed species and arthropod prey, and pieces of plant and animal matter. Foragers collected seeds from 34 plant species, predominantly grasses (genera Gymnopogon, Axonopus, Aristida). Over 6,700 seeds can be stored in nest granaries. Ants and termites were the main animal prey retrieved by P. naegelii. The proportion of seeds and arthropods foraged by P. naegelii changes year-round: in the dry/cold season, the diet is predominantly granivorous, whereas in the wet/warm season, seeds and arthropods are retrieved in more balanced proportions. Although food availability was not assessed, year-round diet of P. naegelii matches the pattern of seasonal abundance of grass seeds and arthropod prey in cerrado. Data on harvester ants come mostly from arid habitats; this study is a first assessment of the ecology of a Neotropical Pogonomyrmex from a moderately moist savanna environment. 相似文献
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