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The alkaloidal fraction from Himatanthus lancifolius barks demonstrated a broad-spectrum in vitro antimicrobial activity for most of the Gram (+) and Gram (-) tested microorganisms. 相似文献
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Antiviral activity of an acidic polysaccharides fraction extracted from Cedrela tubiflora leaves 总被引:1,自引:0,他引:1
An acidic polysaccharides fraction (APS) obtained from Cedrela tubiflora leaves was tested for antiviral activity. This fraction inhibited the replication of HSV-2 and VSV, while the replication of poliovirus was not affected. APS was not virucidal, but no cytotoxicity was present in the different concentrations of APS assayed. 相似文献
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The stem bark of Albizia gummifera has yielded four triterpenes, lupeol, lupenone, vitalboside-A (1) and vitalboside-A 2'-methylglucuronate (2), the last of which appears to be novel. 相似文献
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为了揭示香合欢自然居群表型变异程度和规律,本研究采用方差分析、多重比较、相关性分析等方法,对百色地区6个居群香合欢种子的5个表型性状进行比较研究,讨论居群间和居群内的表型多样性。结果表明:香合欢种子的5个性状在居群内和局群间均存在丰富的变异,平均变异系数在10.68%~49.30%之间,各性状在居群间、居群内个体间均达极显著差异;各性状平均表型分化系数为47.36%,居群间(31.67%)变异略大于居群内(28.67%)变异,说明二者均是香合欢的主要变异来源。种子性状均与海拔呈正相关,与年均降水量呈负相关,但未达到显著水平。研究结果可为香合欢良种选育工作奠定基础,对进一步保护和利用香合欢种质资源具有一定的指导意义。 相似文献
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Rukunga GM Muregi FW Tolo FM Omar SA Mwitari P Muthaura CN Omlin F Lwande W Hassanali A Githure J Iraqi FW Mungai GM Kraus W Kofi-Tsekpo WM 《Fitoterapia》2007,78(7-8):455-459
In the present study the methanolic extract of Albizia gummifera was fractionated into various fractions. These fractions were tested against choroquine sensitive (NF54) and resistant (ENT30) strains of Plasmodium falciparum. All other fractions apart from the alkaloidal fraction showed low activity with IC 50 above 3 microg/ml. The alkaloidal fraction exhibited strong activity against NF54 and ENT30 with IC 50 of 0.16+/-0.05 and 0.99+/-0.06 microg/ml, respectively. Five known spermine alkaloids were isolated from the alkaloidal fraction. These alkaloids exhibited activities against NF54 and ENT30 with IC 50 ranging from 0.09+/-0.02 to 0.91+/-0.10 microg/ml. Four of the alkaloids were further evaluated for in vivo activity against rodent malaria parasite Plasmodium berghei. The alkaloids showed percentage chemosuppression of parasitaemia in mice ranging from 43 to 72%. The use of the extracts A. gummifera for treatment of malaria in traditional medicine seems to have a scientific basis. 相似文献
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川桂叶总黄酮清除DPPH·自由基作用的研究 总被引:1,自引:0,他引:1
用DPPH.自由基检测法测定了川桂叶总黄酮清除自由基的生物活性。在波长为517 nm,反应时间45min的条件下测定了川桂叶总黄酮、芦丁和二丁基羟基甲苯(BHT)清除DPPH自由基的EC50值。结果表明,川桂叶总黄酮对DPPH.自由基具有明显的清除作用,川桂叶总黄酮、芦丁和BHT清除DPPH.自由基的EC50值分别为4.145 mg/L、9.650 mg/L、37.91 mg/L,清除DPPH.自由基能力的大小顺序为川桂叶总黄酮芦丁BHT。 相似文献
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为了筛选最适的菠萝蜜总RNA提取方法,采用Trizol提取法、Tris-硼酸提取法和试剂盒提取法提取菠萝蜜叶片和种子总RNA,通过紫外分光光度计检测、琼脂糖凝胶电泳、RT-PCR检测以及Agilent2100检测,对提取结果进行比较分析。结果表明:采用这3种方法均能从菠萝蜜叶片和种子中提取到总RNA,Tris-硼酸提取法较其他2种方法所提取的总RNA产率高,但杂质较多;采用Tris-硼酸提取法能提取完整性较好的总RNA,28S、18S和5S清晰可见,但提取质量较试剂盒提取法差;试剂盒提取法省时省力,有明显的28S和18S条带,A260/A280分布在1.92~1.98,A260/A230分布在2.04~2.09,叶片总RNA产率42.3ng/μL,种子总RNA产率15.6ng/μL。RT-PCR检测结果表明在约200bp处存在清晰整洁的电泳条带,Agilent2100检测结果显示杂峰极少,28S峰积分面积约是18S峰积分面积的2倍。经综合评定认为,试剂盒提取法是适合菠萝蜜叶片和种子总RNA提取的方法。 相似文献
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采用SDS/酸酚法、Trizol试剂法、常规CTAB法及改良的CTAB法,分别提取5种化学类型樟树叶片总RNA,并对提取效果进行了比较分析。结果表明:Trizol法难以提取樟树叶片总RNA,得率很低;SDS/酸酚法和常规CTAB法得到的RNA存在DNA污染,富含蛋白、多糖、多酚等杂质;这3种方法均不适于富含多糖多酚类物质的樟树叶片总RNA的提取。改良的CTAB法能够提取得到樟树5种化学类型叶片总RNA,且在操作过程中,异樟比油樟和脑樟更易提取。此法能有效去除多糖和蛋白,提取得到的RNA 28S和18S rRNA条带清晰,OD260/OD280值为2.0左右,平均产率分别为115.8μg/g FW。经RT-PCR检测,所得总RNA质量高、完整性好、成功率高,可以满足下一步实验的要求,可作为樟树叶片总RNA提取的首选方法。 相似文献
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Kumarnsit E Keawpradub N Vongvatcharanon U Sawangjaroen K Govitrapong P 《Fitoterapia》2005,76(6):534-539
In the present study, we investigated the effect of the dichloromethane fraction from Areca catechu nut on the severity of naloxone-precipitated morphine withdrawal in morphine-dependent mice. A single intraperitoneal injection of dichloromethane fraction at dose of 125 and 175 mg/kg significantly delayed the onset of withdrawal jumping behavior in a concentration-dependent manner compared to that of saline controls. The dichloromethane fractions also significantly decreased jumping numbers and faecal and urinary excretions during the withdrawal period. 相似文献
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Constituents from the leaves of Rhododendron latoucheae 总被引:2,自引:0,他引:2
Twelve constituents from Rhododendron latoucheae were isolated. Among them, compounds 1 and 2, named rhodolatouside A and B, respectively, are new iridoids. 相似文献
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Complete 1H and 13C NMR assignments are described for two known oleanane glycosides, 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyloleanolic acid and 3-O-beta-D-xylopyranosyl(1-->2)-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl oleanolic acid isolated from the methanol extract of the leaves of Diploclisia glaucescens. 相似文献
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A new monodesmosidic spirostanol saponin, along with three known saponins was isolated from Agave macroacantha Zucc leaves. The structure of the new saponin was established as hecogenin-3-O-α-l-rhamnopyranosyl (1→4) β-d-xylopyranosyl (1→3)[β-d-glucopyranosyl (1→2)] β-d-glucopyranosyl (1→4) β-d-galactopyranoside. The 1H and 13C resonances of the four compounds were assigned using a combination of 1D and 2D NMR techniques including 1H, 13C, COSY, TOCSY, ROESY, HSQC and HMBC NMR and confirmed by mass spectrometry. 相似文献
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《Fitoterapia》2014
Six new 14-noreudesmane sesquiterpenoids, nicotabacosides A–F (1–6), along with five known sesquiterpenoids (7–11), were isolated from the leaves of Nicotiana tabacum. The structures of compounds 1–6 were elucidated as isorishitin 3-O-β-d-glucopyranoside (1), rishitin 3-O-β-d-glucopyranoside (2), rishitin 2-O-β-d-glucopyranoside (3), 1, 6-dehydro-rishitin 3-O-β-d-glucopyranoside (4), 2-hydroxyl-ligudentatol 3-O-β-d-glucopyranoside (5) and oxyglutinosone 3-O-β-d-glucopyranoside (6) based on extensive spectroscopic analyses (HRESIMS, UV, IR, 1D and 2D NMR). Their absolute configurations were determined by X-ray single-crystal diffraction and comparison of their electronic circular dichroism (ECD) spectra. 相似文献