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The methanol extract of the whole plant parts of Polygonum viscosum has yielded a flavonol glycoside, 3-O-(6"-caffeoyl)-beta-D-galactopyranoside (1), the structure of which has been determined unambiguously by UV and a series of one- and two-dimensional NMR experiments, notably, (1)H, (13)C, DEPT, COSY45, HMBC and HMQC. 相似文献
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The multi‐use tree Canthium dicoccum (Rubiaceae) growing in shrub forests of Mysore, Mandya and Chamarajanagar (India) was severely affected by a leaf blight disease. The ascomycete Pestalotiopsis mangiferae was consistently isolated from symptomatic leaves and identified by micromorphology and ITS rDNA sequencing analysis. Pathogenicity test was performed and Koch's postulates were fulfilled. This is the first report of P. mangiferae causing leaf blight of C. dicoccum in India. 相似文献
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《Fitoterapia》2013
Investigation of the crude extract obtained from the aerial parts of Canthium multiflorum led to the isolation of a new iridoid (1) together with twelve known compounds. The structures of these compounds were elucidated by interpretation of 1D and 2D NMR spectroscopic data, accurate mass measurements and comparison with analytical data of previously known analogues. Most of the isolated compounds have been reported for the first time from C. multiflorium. The antimicrobial activities of the isolated compounds were evaluated on five different bacterial strains using agar diffusion technique. The Gram-positive bacterium Staphylococcus aureus subsp. aureus (DSM 799), and the Gram-negative bacteria Actinobacter calco-aceticus (DSM 30006), Serratia plymuthica (DSM 4540), Pseudomonas stutzeri (DSM 4166) and Escherichia coli (DSM 1116) were employed for this purpose. The new iridoid, named 6-oxo-genipin (1), demonstrated significant inhibitory activity against all microbial strains tested, especially the pathogen Staphylococcus aureus. In addition, the compounds 3, 4 and 9 exhibited antiplasmodial activity against Plasmodium falciparum strain K1 and weak cytotoxicity against L6 cell lines. 相似文献
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Nattaya Lourith Takeshi Katayama Kimiko Ishikawa Toshisada Suzuki 《Journal of Wood Science》2005,51(4):379-386
To investigate the biosynthesis and stereochemistry of syringylglycerol-8-O-4′-(sinapyl alcohol) ether (SGSE), a syringyl 8-O-4′ neolignan, feeding experiments and enzyme assays using Eucommia ulmoides were carried out. Diastereoselective formation of erythro-SGSE was found. When [8-14C]sinapyl alcohol was administered to excised shoots of E. ulmoides, 14C was incorporated into free SGSE and SGSE glucosides. In stems, incorporation into (+)-erythro-[14C]SGSE (0.037%) with 9.1% enantiomeric excess (% e.e.) was found; incorporation into the threo isomer was not detectable. Erythro-[14C]SGSE glucosides (0.047%) dominated over threo forms (0.007%) with 74.0% diastereomeric excess (% d.e.); both diastereomers were levorotatory with 32.0% e.e. and 18.3% e.e., respectively. In leaves, higher incorporation into (−)-erythro-[14C]SGSE (0.500%, 15.9% e.e.) than into the threo isomer (0.206%, 7.4% e.e.) was observed (41.6% d.e.). (−)-Erythro-[14C]SGSE glucosides (1.692%, 25.0% e.e.) were produced at higher rates than threo isomers (0.177%, 16.4% e.e.) with 81.0% d.e. In incubations of a mixture of [8-14C]sinapyl and [8-14C]coniferyl alcohols with an insoluble enzyme preparation from stems of E. ulmoides, erythro-SGSE was preferentially produced. The highest % d.e. (82.8) was observed at 60 min with the (+)-erythro isomer (21.4% e.e.) and the (−)-threo form (4.3% e.e.).Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002, and the 47th Lignin Symposium, Fukuoka, October 2002 相似文献
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Carine Mvot Akak Céline Mbazoa Djama Augustin Ephrem Nkengfack Peng-Fei Tu Lian-Di Lei 《Fitoterapia》2010
Two new 5-methylcoumarin glycosides named diosfeboside A (1) and B (2) and five known compounds namely kaempferol 3-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (3), ursolic acid (4), betulinic acid (5), stigmasterol (6) and stigmasterol 3-O-β-d-glucopyranoside (7) were isolated from the leaves of Diospyros crassiflora (Hiern). Their structures were established through interpretation of 1 and 2D NMR, mass spectra analysis and comparison with reported data. In vitro cytotoxic activity of the new compounds against human carcinoma cell lines (HL-60, Bel-7402, BGC-823, and KB) was evaluated and no cytotoxicity was observed for each of them. 相似文献
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Khalijah Awang Xe-Min Loong Kok Hoong Leong Unang Supratman Marc Litaudon Mat Ropi Mukhtar Khalit Mohamad 《Fitoterapia》2012
A study on the leaves of Aglaia exima led to the isolation of one new and seven known compounds: six triterpenoids and two steroids. Their structures were elucidated and analyzed mainly by using spectroscopic methods; 1D and 2D NMR, mass spectrometry, UV spectrometry and X-ray. All the triterpenoids and steroids were measured in vitro for their cytotoxic activities against eight cancer cell lines; lung (A549), prostate (DU-145), skin (SK-MEL-5), pancreatic (BxPC-3), liver (Hep G2), colon (HT-29), breast (MCF-7) and (MDA-MB-231). The new cycloartane triterpenoid, 24(E)-cycloart-24-ene-26-ol-3-one 1, showed potent cytotoxic activity against colon (HT-29) cancer cell line (IC50 11.5 μM). 相似文献
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Three new water-soluble alkaloids (1-3) together with twelve known compounds (4-15) have been isolated from the water extract of leaves of Suregada glomerulata. Their structures were determined by spectroscopic analysis and chemical method. Compounds 1-3 were evaluated for their in vitro inhibitory activity against α-glucosidase and HIV-1 replication. However, no significant activities were found. 相似文献
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Stereochemistry and biosynthesis of guaiacylglycerol-8-O-4′-(sinapyl alcohol) ether (GGSE), an 8-O-4′ neolignan, which consists of coniferyl and sinapyl alcohol moieties, in Eucommia ulmoides were investigated. Four 8-O-4′ neolignans, GGSE, syringylglycerol-8-O-4′-(coniferyl alcohol) ether (SGCE), guaiacylglycerol-8-O-4′-(coniferyl alcohol) ether (GGCE), and syringylglycerol-8-O-4′-(sinapyl alcohol) ether (SGSE), were synthesized. Their erythro and threo diastereomers were separated through acetonide derivatives, intermediates of the synthesis, and identified by means of nuclear magnetic resonance (NMR) spectroscopy. All of the erythro-acetonide derivatives have larger coupling constants (ca 9 Hz) for the C7-H resonances than those of the threo ones (1.5–2 Hz). In the case of the four 8-O-4′ neolignans, the C7-H coupling constants of the threo-isomers are not smaller than those of the erythro ones. GGSE isolated previously from this plant was identified as the erythro isomer by comparison of the 13C-NMR data with synthetic erythro-GGSE and threo-GGSE and the other 8-O-4′ neolignans mentioned as above. Administration of a mixture of [8-14C]coniferyl alcohol and [8-14C]sinapyl alcohol to excised shoots of E. ulmoides was carried out and the incorporation of 14C into erythro-[14C]GGSE was found to be higher than that in threo-[14C]GGSE. The occurrence of diastereoselective formation of erythro-GGSE by cross coupling of coniferyl and sinapyl alcohols is suggested.Part of this paper was presented at the 47th Lignin Symposium, Fukuoka, October 2002 and the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, April 2003 相似文献
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Singsaas EL Laporte MM Shi JZ Monson RK Bowling DR Johnson K Lerdau M Jasentuliytana A Sharkey TD 《Tree physiology》1999,19(14):917-924
Because the rate of isoprene (2-methyl-1,3-butadiene) emission from plants is highly temperature-dependent, we investigated natural fluctuations in leaf temperature and effects of rapid temperature change on isoprene emission of red oak (Quercus rubra L.) leaves at the top of the canopy at Harvard Forest. Throughout the day, leaves often reached temperatures as much as 15 degrees C above air temperature. The highest temperatures were reached for only a few seconds at a time. We compared isoprene emission rates measured when leaf temperature was changed rapidly with those measured when temperature was changed slowly. In all cases, isoprene emission rate increased with increasing leaf temperature up to about 32 degrees C and then decreased with higher temperatures. The temperature at which isoprene emission rates began to decrease depended on how quickly measurements were made. Isoprene emission rates peaked at 32.5 degrees C when measured hourly, whereas rates peaked at 39 degrees C when measurements were made every four minutes. This behavior reflected the rapid increase in isoprene emission rate that occurred immediately after an increase in leaf temperature, and the subsequent decrease in isoprene emission rate when leaf temperature was held steady for longer than 20 minutes. We concluded that the observed temperature response of isoprene emission rate is a function of measurement protocol. Omitting this parameter from isoprene emission models will not affect simulated isoprene emission rates at mild temperatures, but can increase isoprene emission rates at high temperatures. 相似文献
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Radical scavenging activity and composition of raspberry (Rubus idaeus) leaves from different locations in Lithuania 总被引:1,自引:0,他引:1
Raspberry (Rubus idaeus) leaves, collected in different locations of Lithuania were extracted with ethanol and the extracts were tested for their antioxidant activity (AA) by using ABTS(.)(+) decolourisation and DPPH(.) scavenging methods. All extracts were active, with radical scavenging capacity at the used concentrations from 20.5 to 82.5% in DPPH(.) reaction system and from 8.0 to 42.7% in ABTS(.)(+) reaction. The total amount of phenolic compounds in the leaves varied from 4.8 to 12.0 mg of gallic acid equivalents (GAE) in 1 g of plant extract. Quercetin glucuronide, quercetin-3-O-glucoside and rutin were identified in the extracts. 相似文献
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A survey of the hexane extract of the leaves of Elaeophorbia drupifera led to the isolation of a new triterpenoid named elaeophorbate [methyl 4,4,8,10,13,14-hexamethyl-1,17-di (prop-1-en-2-yl)hexadecahydro-1H-cyclo penta[a]phenanthrene-3-carboxylate, 5] and eight known triterpenoids. Based on spectroscopic methods, coupled with high resolution gas chromatography-mass spectrometry the structures of all the compounds were elucidated. 相似文献