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1.
The ethanol extracts of Omalanthus nervosus leaves, stem and root barks, were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity, ethyl acetate fractions being in all cases the more active. No fraction was active against tested moulds. 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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油茶叶乙醇提取物清除DPPH自由基作用的研究 总被引：3，自引：0，他引：3
用二苯基苦基肼自由基(DPPH·)法测定了油茶叶乙醇提取物的抗氧化活性,并与芦丁、二丁基羟基甲苯(BHT)进行了比较,在波长517 nm、反应时间40 min的条件下测定了DPPH·的清除率为50%时抗氧化剂的质量浓度(EC50)值.结果表明,油茶叶乙醇提取物时DPPH·具有明显的清除作用,且随着油茶叶乙醇提取物纯化程度的提高,其清除能力也相应增强.测得油茶叶粗提物、油茶叶精提物、芦丁和BHT清除DPPH·的EC50值分别为12.19、6.765、9.481和37.53 mg/L,清除DPPH·能力的大小顺序依次为油茶叶精提物＞芦丁＞油茶叶粗提物＞BHT. 相似文献
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杜仲叶提取物的抑菌活性研究 总被引：1，自引：0，他引：1
为了发现新的抑茵材料,对杜仲叶70％(体积分数)乙醇提取物及其分级组分进行了抑菌试验.结果显示:杜仲叶的乙醇和乙酸乙酯提取物对细菌和真茵都有抑制作用,而且乙酸乙酯提取物对黄曲霉和黑曲霉有特殊的抑制特征;正丁醇和水提取物对细菌有抑制作用,但对真菌几乎没有抑制作用;石油醚提取物几乎对细菌和真茵都没有抑制作用.最大抑茵圈直径超过了10 mm,最小抑茵浓度(MIC)在0.25％～3.0％之间.杜仲叶提取物在抑菌活性方面具有一定的热稳定性,抑茵率随时间而逐渐增加,16 h之后基本保持不变. 相似文献
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Anti-microbial activity of Bidens pilosa, Bischofia javanica, Elmerillia papuana and Sigesbekia orientalis. 总被引：1，自引：0，他引：1
The ethanol extracts of Bidens pilosa (whole plant), Bischofia javanica (leaves), Elmerillia papuana (root bark) and Sigesbekia orientalis (whole plant) were partitioned (petrol, dichloromethane, ethyl acetate). The crude ethanolic extracts and all the obtained fractions showed a broad spectrum of antibacterial activity, the ethyl acetate fractions and the petrol fraction of E. papuana being the most effective. No activity was observed against the tested moulds. 相似文献
7.
The ethanol and methanol extracts of Arbutus unedo leaves were screened for antioxidant activity. The antioxidant activity was determined by an improved assay based on the decolorization of the radical monocation of [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS). The ethanol and methanol extract of A. unedo leaves displayed potent antioxidant activity. 相似文献
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The biological activities of ethanol and petroleum ether extracts from leaves and fruits of Schinus molle against adults of Blattella germanica were examined by repellence test and topical application. All extracts produced significant repellent effect and mortality. 相似文献
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n-Hexane, ethanol and water extracts of Laurus nobilis L. leaves were evaluated for cytotoxic properties using the Brine shrimp bioassay. Only the n-hexane extract exhibited cytotoxic activity. 相似文献
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桑叶总黄酮的提取及其抑菌活性研究 总被引：2，自引：0，他引：2
以抑菌活性为评价指标,对桑叶总黄酮的提取工艺进行了优化,并对优化条件下得到的粗提物采用不同溶剂进行分级提取和定性分析,测定了各萃取物的总黄酮含量,考察了萃取物对大肠杆菌、金黄色葡萄球菌的抑菌圈直径、最低抑菌浓度,选取抑菌效果最佳的萃取物进行了稳定性实验。结果表明,桑叶总黄酮提取的最佳条件为:温度70℃,乙醇体积分数70%,提取时间4 h,固液比1∶30(g∶mL);抑菌效果最佳的为乙酸乙酯萃取物,且乙酸乙酯部分对温度和紫外线照射的影响均具有良好的稳定性。 相似文献
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The cytotoxic activity against some tumor cell lines of 16 commonly used species of Asarum was evaluated in this study. All of these plants were widely used in Asian countries as traditional medicines or folk medicines. Their inhibitory activities against four tumor cell lines (HL-60, BGC-823, KB and Bel-7402) were compared. It was observed that 10 of the tested extracts (eight ethanol extracts and two water extracts) among 32 extracts of these plants showed cytotoxic activity. Those 95% ethanol extractions from A. caudigerellum, A. forbesii, A. inflatum and A. maximum exhibited the highest cytotoxic activity, and 95% ethanol extracts or water extracts of A. sieboldii var. seoulense, A. himalaicum, A. splendens and A. crispulatum showed selective activity against one or two cells among the tested tumor cells. This is the first report of Asarum plants possessing cytotoxic activity against tumor cell lines. 相似文献
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为了研究对节白蜡的抗病原因,以探寻新的生物农药,在前期有关对节白蜡树叶提取物杀菌活性研究的基础上,对其乙酸乙酯提取物及柱层析分离组分进行了GC-MS分析,初步确认了各组分所含化合物的可能结构。结果表明:乙酸乙酯提取物中面积归一含量超过1%的化合物组分有18个,其中3号化合物的面积归一含量为17.13%,其结构为4-羟苯基乙醇;经过柱层析分离后各组分所含化合物要相对集中和更加纯化些,其中组分A所含物质主要有两个,化合物4-羟苯基乙醇的含量达到了81.3%,这是相对比较纯的物质;作者据其已有的相关研究结果(组分A整体表现出的杀菌活性要优于其他组分)分析认为,4-羟苯基乙醇作为对节白蜡树叶中所含的重要化合物,在对节白蜡的抗病方面起到了重要作用。 相似文献
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The petroleum ether and ethanol extracts of Vitex trifolia leaves exhibited moderate inhibiting activity against both gram-positive and gram-negative bacteria. 相似文献
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瑞香的叶提取物对月季长管蚜有较强毒杀作用。用水提醇沉法和醇提水沉法获得的提取物对蚜虫的致死中浓度(LC50)3963mg/L和6397mg/L。水提醇沉提取物的乙酸乙酯萃取物对月季长管蚜的毒力较其它萃取物强,其LC50为1953mg/L,结果表明:瑞香叶含有杀虫活性物质主要存在于乙酸乙酯萃取物中。对水提醇沉提取物进行硅藻土柱层析分离,得到的第三组分得率和灭蚜效果均优于氧化铝柱层析离到的第三组分。 相似文献
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Successive petroleum ether, benzene, chloroform, ethyl acetate and methanol extracts of Chukrasia tabularis leaves were tested for their phytochemical constituents, antibacterial and antifungal activity. The ethyl acetate and methanol extracts were found to be most effective against most of the tested organisms. 相似文献
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The methanol, hexane and diethyl ether extracts from both leaves and roots of Withania somnifera were evaluated for the antibacterial/synergistic activity by agar plate disc-diffusion assay against Salmonella typhimurium and Escherichia coli. Different concentrations of Tibrim, a combination of rifampicin and isoniazid, were tested to find out the minimum inhibitory concentration (MIC), which came out to be 0.1 mg/ml for S. typhimurium and E. coli. From the six extracts tested, only methanol and hexane extracts of both leaves and roots were found to have potent antibacterial activity. A synergistic increase in the antibacterial effect of Tibrim was noticed when MIC of Tibrim was supplemented with these extracts. 相似文献
18.
竹叶总黄酮提取纯化工艺研究 总被引：3，自引：0，他引：3
以芦丁为对照,竹叶总黄酮得率为考察指标,通过正交试验法优选破碎提取竹叶总黄酮的最佳工艺.在此基础上,采用真空薄膜浓缩,超声波脱色,大孔树脂Diaion HP-20吸附分离纯化竹叶总黄酮提取物.结果表明,20 g竹叶粗粉最佳提取工艺为用80%(体积分数)乙醇做溶剂,液固比为10:1(mL:g)提取1次,5 min.最佳分离纯化工艺为:采用大孔树脂Diaion HP-20进行分离富集,以不同浓度的乙醇进行梯度洗脱,洗脱流速为5mL/min,收集并减压浓缩各洗脱部分的总黄酮提取物,精制后的总黄酮纯度可达76%. 相似文献
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The antibacterial activity of the chloroform, acetone and methanol extracts of endemic Hypericum kazdaghensis leaves were evaluated by disc diffusion method. All extracts exhibited antimicrobial activity against all tested bacteria. 相似文献
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Hexanic extracts from leaves and fruits of Schinus molle were tested for repellent and insecticidal properties against first instar nymphs and eggs of Triatoma infestans, the vector of Chagas' disease. Leaf and fruit extracts were highly repellent for first nymphs. Fruit extracts had also ovicidal activity. 相似文献