共查询到19条相似文献，搜索用时 93 毫秒
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为明确广东石豆兰的抗氧化能力及抗氧化成分,以鳞茎为材料,以甲醇、乙醇、丙酮和乙酸乙酯为提取剂得到4种提取物,测定了4种提取物中总黄酮、总酚含量及其抗氧化活性,并分析了两者之间的关系。结果表明,石豆兰总酚含量高于总黄酮,乙醇为总酚和总黄酮2种物质的最佳提取溶剂;甲醇提取物对羟基自由基清除力和对Fe2+的螯合力最强,对DPPH自由基清除效果最差;丙酮提取物具有最强的总还原力和清除超氧阴离子的能力,而清除羟基自由基能力最弱;乙酸乙酯提取物清除DPPH自由基的能力最强,但总还原力、清除超氧阴离子的能力、Fe2+的螯合力最弱。此外,除了DPPH自由基外,其他4个抗氧化指标与总黄酮或总酚含量呈正相关(0.185<r<0.969),总还原力与总黄酮含量呈显著相关。本研究结果为广东石豆兰抗氧化物质的提取及进一步开发利用提供了参考依据。 相似文献
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为了分离纯化银杏花粉中具有潜在抗氧化活性的黄酮组分及研究其潜在抗氧化活性,该文对银杏花粉的总黄酮进行提取和分步萃取,采用1,1-diphenyl-2-picrylhydrazyl(DPPH)自由基清除率检测和组分分析锁定待纯化萃取相。通过DPPH-HPLC-PAD技术筛选目标清除自由基组分,并采用制备型液相色谱技术分离纯化这些组分,然后采用紫外可见吸收光谱、质谱、核磁共振氢谱、碳谱等技术进行结构鉴定,最后通过测定DPPH自由基清除率初步研究其潜在抗氧化活性。结果显示,银杏花粉粗提物具有清除DPPH自由基活性,对DPPH的半抑制率(IC50值)为1.32 mg/m L,乙酸乙酯相和正丁醇相的IC50值为0.46、0.84 mg/m L,分别是粗提物的34.85%和63.64%。可见,乙酸乙酯相的清除DPPH活性最高。进一步研究显示,乙酸乙酯相富集了6种主要银杏花粉黄酮,而且均具有清除DPPH活性。经纯化和结构鉴定分别为山奈酚-3,4’-双-O-β-D-葡萄糖苷(1)、山奈酚-3-O-β-D-葡萄糖基-7-O-α-L-鼠李糖苷(2)、山奈酚-3-O-β-D-葡萄糖苷(3)、山奈酚-3-O-α-L-鼠李糖苷(4)、柚皮素(5)和山奈酚(6)。其清除DPPH自由基的活性由高到低依次为:化合物6化合物2化合物3化合物4化合物1化合物5。其中山奈酚清除DPPH的IC50值为0.017 mg/m L,与维生素C及芦丁相比没有显著性差异(P0.05)。上述研究为银杏花粉功能成分的深入研究奠定了基础。 相似文献
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为了探究墨鱼缠卵腺糖蛋白(CGG)的抗氧化活性及抑菌活性,本试验通过测定CGG的超氧阴离子自由基清除率、DPPH自由基清除率、羟基自由基清除能力、小鼠体内过氧化氢酶(CAT)活性及谷胱甘肽过氧化物酶(GSH-PX)活性等研究CGG体内外抗氧化活性,并通过抑菌试验探讨了CGG的抑菌活性。结果表明,随着CGG浓度的增大,超氧阴离子自由基清除率从17.51%增加至55.84%,DPPH自由基清除率从5.7%增加至19.5%,羟基自由基清除能力从10.38%增加至57.94%;与对照组相比, 低、中、高剂量组小鼠体内的CAT 活性分别提高了21.91%、126.29%、135.63%,GSH-PX活性分别提高了2.04%、24.69%、28.13%。抑菌试验结果表明,当CGG浓度为14 mg·mL-1时,大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)、假单胞菌(Pseudomonadaceae)的抑菌圈分别为15.7、13.6、12.5 mm,MIC分别为1.25、7、7 mg·mL-1,MBC分别为14、28、14 mg·mL-1。综上表明,CGG具有一定的抗氧化和抑菌活性,但抑菌效果较弱。本研究结果为墨鱼缠卵腺的合理利用提供了一定的理论基础,同时对提高水产资源利用率有一定的参考价值。 相似文献
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从海产虾壳上分离筛选拮抗放线菌、研究其抑菌活性具有重要的实践意义。藤黄轮丝链霉菌(Streptomyces luteoverticillatus)T0907-107是分离自海产虾壳上并经初筛和鉴定的一株链霉菌,为了进一步开发和利用该菌,本研究采用极性不同的5种溶剂(丙酮、乙酸乙酯、正丁醇、乙醇和甲醇),对该菌株的发酵液菌体活性物质进行了提取,对粗提物的理化性质和抑菌活性进行了初步研究。结果表明,其发酵液活性物质大部分存在于菌体中,采用甲醇和丙酮浸提的效果好,其抑菌圈直径分别为26.20和22.50 mm;对粗提物进行耐热性实验,结果表明,粗提物是一种能够耐60℃高温和一定酸碱的物质;粗提物对蛋白酶K稳定;菌体及粗提物对多种植物病原菌物如烟草炭疽病菌(Colletotrichum nicotianae Sacc.)、烟草赤星病菌(Alternaria alternata(Fries)Keissler)、烟草立枯丝核病菌(Rhizoctonia solani Kühn)、枇杷炭疽菌(C.gloeosporioides(Penz.)Sacc.)和白菜炭疽病菌(C.higginsianum Sacc.)有较强抑制作用。研究结果表明,甲醇和丙酮是较合适的萃取溶剂,该菌发酵液菌体粗提物极性强、稳定性好、有较广的抑菌谱,显示出好的开发前景。本研究为进一步鉴定该活性物质及开发和利用该菌提供了基础资料。 相似文献
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开口箭提取物对采后香蕉抗炭疽病菌活性的研究 总被引：4，自引：0，他引：4
为探讨植物提取物对香蕉采后病害的防治，采用孢子萌发法和菌丝生长速率测定百合科植物开口箭的甲醇提取物及其乙酸乙酯分部萃取物和正丁醇分部萃取物对香蕉炭疽病菌的离体抗菌活性，选用正丁醇分部萃取物进行耐高温(121℃处理20 min)、紫外光照射(30 W紫外灯距50 cm直射15 h)和酸处理(调节pH 3)的抗菌稳定性研究，并进行了提取物处理香蕉的贮藏防病试验。结果表明，开口箭甲醇提取物及其乙酸乙酯分部萃取物和正丁醇分部萃取物抑制香蕉炭疽病菌孢子萌发的半效应浓度(EC50)分别为1490.27，638.40，1112.65 μg/mL，抑制香蕉炭疽病菌菌丝生长的EC50分别为1262.16，451.02，955.58 μg/mL，正丁醇分部萃取物的抗菌活性不受热、紫外线和酸等因子的影响，用开口箭提取物处理采后香蕉果实，具有明显降低其潜伏性炭疽病发病率的作用。 相似文献
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为探明稻鸭共养模式抑制水稻纹枯病发生的原因,以稻鸭共养模式的鸭粪提取物为研究对象,对其抑菌活性及有效成分进行了测定和分析,以期为水稻纹枯病生物防治提供新的途径。结果表明:鸭粪乙醇提取物对水稻纹枯病菌有抑制作用,24h内最高菌丝生长抑制率和EC50分别为88.64%、26.11mg·mL-1;鸭粪乙醇提取物经萃取分离得到石油醚和乙酸乙酯两种组分,其中石油醚组分抑菌效果较弱,乙酸乙酯组分抑菌能力较强,其对水稻纹枯病菌抑制率为89.70%,EC50为15.52mg·mL-1;对乙酸乙酯组分进行硅胶柱层析分离得到5种流份,其中第2流份有显著抑菌活性,在24h和48h内对水稻纹枯病菌的抑制率分别为89.58%和80.36%。GC-MS分析表明,鸭粪的抑菌物质主要为酚酸类和含硫醇有机物质,进一步纯化和鉴定有待研究。 相似文献
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爵床提取物的抑菌杀虫活性研究 总被引：1，自引：0，他引：1
爵床(Justicia procumbens var.procumbens L.)是一种传统中药。为探明爵床提取物的抑菌杀虫活性,采用冷浸和超声波提取相结合的方法,分别获得了爵床甲醇、氯仿、丙酮、乙酸乙酯和正己烷等溶剂提取物;并应用抑菌圈法研究了5种提取物对柑橘炭疽病菌(Colletotrichum gloeosprioides)、芦笋茎枯病菌(Phomopsisasparagi)、稻瘟病菌(Pyricularia grisea)、棉花红腐病菌(Fusarium graminearum)和草莓灰霉病菌(Botrytiscinerea)等5种植物病原真菌的抑制效果,测定了甲醇提取物对柑橘炭疽病、芦笋茎枯病、草莓灰霉病和柑橘溃疡病(Xanthomonas campestris)等4种植物病菌及白蚊伊蚊(Aedes albopictus)、家蝇(Musca domestica)和菜青虫(Pieris rapae)等3种害虫的毒力。结果表明,不同极性溶剂提取物8 mg.mL 1对5种植物病原真菌均有一定的抑制作用,其中甲醇提取物对柑橘炭疽病菌、芦笋茎枯病菌、草莓灰霉病菌的抑制率均达50%以上。爵床甲醇提取物具有较强的抑菌杀虫活性,对柑橘炭疽病菌、芦笋茎枯病菌和草莓灰霉病菌菌丝生长的抑制中浓度(EC50)分别为5.94 mg.mL 1、4.61 mg.mL 1和5.27 mg.mL 1,EC90分别为63.69 mg.mL 1、58.01 mg.mL 1和54.57 mg.mL 1;0.25~1.00 mg.mL 1爵床甲醇提取物对柑橘溃疡病病菌显示强抑菌作用,0.125 mg.mL 1显示中度抑菌作用,最小抑制浓度(MIC)为0.062 5 mg.mL 1;爵床甲醇提取物对白蚊伊蚊、家蝇和菜青虫的致死中浓度(LC50)分别为0.195 8 mg.mL 1、0.351 4 mg.mL 1和0.287 7 mg.mL 1,LC95分别为0.988 4 mg.mL 1、3.053 2mg.mL 1和2.584 4 mg.mL 1。因此,爵床提取物作为生物农药,在农业生产中具有较好的应用前景。 相似文献
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为有效利用牛樟芝资源,以人工固体培养牛樟芝菌丝体为原料,采用响应面法优化牛樟芝总三萜超声辅助提取工艺,比色法评价牛樟芝总三萜体外抗氧化活性,滤纸片法研究牛樟芝总三萜的体外抑菌活性。结果表明,超声辅助提取牛樟芝总三萜的最佳工艺条件为:提取时间41 min、提取功率80 W、料液比1∶20,总三萜得率为3.84%±0.18%。牛樟芝三萜提取物具有较强的还原能力,并能有效清除DPPH自由基、ABTS自由基和超氧阴离子自由基,其半清除浓度(EC_(50))分别为0.29、0.50、0.33mg·m L~(-1),且清除率与质量浓度存在剂量效应关系;牛樟芝总三萜对大肠杆菌、金黄色葡萄球菌及枯草芽孢杆菌均具有明显的抑制作用,同浓度下对金黄色葡萄球菌具有较高的抑菌活性。本研究结果为人工固体栽培牛樟芝活性成分的综合开发利用提供了依据。 相似文献
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从不同种奇球菌属(Deinococci)细菌中分离提取类胡萝卜素,并利用高效液相色谱分析了提取物的组成和性质。通过DPPH自由基和超氧自由基清除试验,比较了不同菌种来源的类胡萝卜素提取物的抗氧化能力,结果发现,D.radiopugnans和D.radiodurans提取物的体外抗氧化能力最强,在浓度为0.6μg/ml时DPPH自由基清除率都达到46%左右;D.radiopugnans提取物的超氧自由基清除活性较强,在浓度为3μg/ml时清除率达到42.99%。同时,采取体外蛋白质氧化抑制试验和脂类氧化抑制能力测定分析比较了不同种类提取物对大分子的保护作用,结果表明D.radiopugnans和D.radiodurans提取物具有较强的生物大分子氧化防护功能。以上研究为从具有极端环境适应能力的奇球菌属筛选抗氧化活性类胡萝卜素,并进一步研究其作用机制提供了基础。 相似文献
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Ozer H Sökmen M Güllüce M Adigüzel A Sahin F Sökmen A Kiliç H Baris O 《Journal of agricultural and food chemistry》2007,55(3):937-942
Hippomarathrum microcarpum grows wild in eastern Anatolia, Turkey, and is a plant utilized as food by people. In this study, the in vitro antimicrobial and antioxidant activities of the essential oil and methanol extract from H. microcarpum and its essential oil composition were investigated. The essential oil, which has bornyl acetate, caryophyllene oxide, and beta-caryophyllene as its main components, exhibited activity against eight bacteria, nine fungi, and a yeast, Candida albicans, with minimum inhibitory concentration values ranging from 62.50 to 125 muL/mL; the methanol extract showed weak activity. The antioxidant activity of these extracts was assessed by the beta-carotene bleaching test and the 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test. The inhibition of linoleic acid oxidation was very weak for both extracts tested. The inhibition percentages were found to be 22.9 and 33.5% for methanol and essential oil, respectively, at the concentration of 2 g/L. The oil scavenged DPPH at higher concentrations (IC50 = 10.69 +/- 0.05 mg/mL), but the methanol extract exhibited no activity. The total phenolic content of the methanol extract was found to be 4.7 +/- 0.1%. 相似文献
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The antioxidant activities of oat groat extracts using different solvents were investigated. For acetone, hexane, and methanol extracts, the total phenolic compound contents were 12.83, 8.56, and 26.17 μg of catechin equivalent/g, respectively. Their corresponding free radical scavenging activities measured using the DPPH (2,2'‐diphenyl‐1‐picrylhydrazyl) method were 0.68, 0.35, and 0.79 μmol of Trolox equivalent/g, respectively. All oat extracts presented significantly greater capability in preventing cholesterol oxidation than the control (no extract added) during heating at the three levels of addition (1, 5, and 10 mg). The capability of the hexane or acetone extract in preventing cholesterol oxidation was not as effective as the methanol extract. In the docosahexaenoic acid (DHA, C22:6) oxidation test, all oat extracts at the level of 5 and 10 mg had greater inhibition capability on DHA oxidation than the control (DHA only). No significant inhibition was found for the hexane and acetone extract at the level of 1 mg, except for the methanol extract. The capabilities of oat extracts to inhibit oxidation of cholesterol and DHA from high to low was methanol, acetone, and hexane extract, which agreed with their free radical scavenging activities and total phenolic compound contents. 相似文献
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Oki T Masuda M Kobayashi M Nishiba Y Furuta S Suda I Sato T 《Journal of agricultural and food chemistry》2002,50(26):7524-7529
The extracts from white-, black-, and red-hulled rice were prepared by sequential extraction with six different polar solvents, and their radical-scavenging activities were measured by methods using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH*) and tert-butyl hydroperoxyl radical (t-BuOO*). The extracts prepared with highly polar solvents, methanol and deionized water, exhibited higher DPPH* and t-BuOO* scavenging activities in all three cultivars. In addition, the acetone extract from red-hulled rice exhibited a high DPPH* and t-BuOO* scavenging activity, while no such activity was detected for the acetone extracts from white- and black-hulled rice. The major components responsible for the radical scavenging in the acetone extract from red-hulled rice were identified as procyanidins by acidic hydrolysis, vanillin assay, and Sephadex LH-20 chromatography. GPC analysis of the acetylated procyanidins revealed that the average molecular weight is about 5000, in a range of about 500-18,000. 相似文献
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Zhao H Dong J Lu J Chen J Li Y Shan L Lin Y Fan W Gu G 《Journal of agricultural and food chemistry》2006,54(19):7277-7286
Four kinds of solvent extracts from three Chinese barley varieties (Ken-3, KA4B, and Gan-3) were used to examine the effects of extraction solvent mixtures on antioxidant activity evaluation and their extraction capacity and selectivity for free phenolic compounds in barley through free radical scavenging activity, reducing power and metal chelating activity, and individual and total phenolic contents. Results showed that extraction solvent mixtures had significant impacts on antioxidant activity estimation, as well as different extraction capacity and selectivity for free phenolic compounds in barley. The highest DPPH* and ABTS*+ scavenging activities and reducing power were found in 80% acetone extracts, whereas the strongest *OH scavenging activity, O2*- scavenging activity, and metal chelating activity were found in 80% ethanol, 80% methanol, and water extracts, respectively. Additionally, 80% acetone showed the highest extraction capacity for (+)-catechin and ferulic, caffeic, vanillic, and p-coumaric acids, 80% methanol for (-)-epicatechin and syringic acid, and water for protocatechuic and gallic acids. Furthermore, correlations analysis revealed that TPC, reducing power, DPPH* and ABTS*+ scavenging activities were well positively correlated with each other (p < 0.01). Thus, for routine screening of barley varieties with higher antioxidant activity, 80% acetone was recommended to extract free phenolic compounds from barley. DPPH* scavenging activity and ABTS*+ scavenging activity or reducing power could be used to assess barley antioxidant activity. 相似文献
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El-Ghorab A Shaaban HA El-Massry KF Shibamoto T 《Journal of agricultural and food chemistry》2008,56(13):5021-5025
Volatile chemicals in a dichloromethane extract from a steam distillate of juniper berry fruit (Juniperus drupacea L.) and its two column chromatographic fractions (eluted with hexane and ethyl ether) were analyzed by gas chromatography/mass spectrometry. The major compounds in the dichloromethane extract were alpha-pinene (23.73%), thymol methyl ether (17.32%), and camphor (10.12%). A fraction eluted with hexane contained alpha-pinene (44.24%) as the major constituent. A fraction eluted with ethyl ether had thymol methyl ether (22.27%) and camphor (19.65%) as the main components. Three samples prepared from the distillate and two additional samples prepared by petroleum ether and ethanol extraction directly from juniper berry fruits exhibited clear antioxidant activities with dose response in both 1,2-diphenyl picrylhydrazyl and beta-carotene assays. All samples except the hexane fraction showed comparable activities to that of the synthetic antioxidant t-butyl hydroquinone at a level of 200 microg/mL in the two testing systems. The extracts of dichloromethane, petroleum ether, and ethanol exhibited appreciable antimicrobial activities against six microorganisms with minimum inhibitory concentrations ranging from 0.5 mg/mL (volatile extract against Candida albicans ) to 1.2 mg/mL (ethanol extract against Aspergillus niger ). The results of the present study suggest that this fruit could be a natural antioxidant supplement for foods and beverages. 相似文献
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Patro BS Bauri AK Mishra S Chattopadhyay S 《Journal of agricultural and food chemistry》2005,53(17):6912-6918
The 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay of the ether, methanol, and aqueous extracts of the spice Myristica malabarica (rampatri) revealed the methanol extract to possess the best antioxidant activity. Column chromatography of the methanol extract led to the isolation of a new 2-acylresorcinol and four known diarylnonanoids of which the diarylnonanoid, malabaricone C, showed the maximum DPPH scavenging activity. Malabaricone C could prevent both Fe(II)- and 2,2'-azobis(2-amidinopropane)dihydrochloride-induced lipid peroxidation (LPO) of rat liver mitochondria more efficiently than curcumin. The anti-LPO activity of malabaricone C was attributed to its better radical scavenging and Fe(II) chelation capacities. The superior activity of malabaricone C was rationalized by a systematic structure-activity correlation of the results obtained with the structurally related diarylnonanoids and curcumin. Malabaricone C also prevented the gamma-ray-induced damage of pBR322 plasmid DNA in a concentration-dependent manner. The radioprotective activity was found to correlate with its (*)OH radical scavenging property, which matched well with that of d-mannitol. 相似文献
18.
The antioxidant activities, reducing powers, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities, amount of total phenolic compounds, and antimicrobial activities of ether, ethanol, and hot water extracts of the leaves and seeds of Rumex crispus L. were studied. The antioxidant activities of extracts increase with increasing amount of extracts (50-150 microg). However, the water extracts of both the leaves and seeds have shown the highest antioxidant activities. Thus, addition of 75 microg of each of the above extracts to the linoleic acid emulsion caused the inhibition of peroxide formation by 96 and 94%, respectively. Although the antioxidant activity of the ethanol extract of seed was lower than the water extract, the difference between these was not statistically significant, P > 0.05. Unlike the other extracts, 75 microg of the ether extract of seeds was unable to show statistically significant antioxidant activity, P > 0.05 (between this extract and control in that there is no extract in the test sample). Among all of the extracts, the highest amount of total phenolic compound was found in the ethanol extract of seeds, whereas the lowest amount was found in the ether extract of seeds. Like phenolic compounds, the highest reducing power and the highest DPPH scavenging activity were found in the ethanol extract of seeds. However, the reducing activity of the ethanol extract of seeds was approximately 40% that of ascorbic acid, whereas in the presence of 400 microg of water and ethanol extracts of seeds scavenging activities were about 85 and 90%, respectively. There were statistically significant correlations between amount of phenolic compounds and reducing power and between amount of phenolic compounds and percent DPPH scavenging activities (r = 0.99, P < 0.01, and r = 0.864, P < 0.05, respectively) and also between reducing powers and percent DPPH scavenging activities (r = 0.892, P < 0.05). The ether extracts of both the leaves and seeds and ethanol extract of leaves had shown antimicrobial activities on Staphylococcus aureus and Bacillus subtilis. However, none of the water extracts showed antimicrobial activity on the studied microorganisms. 相似文献
19.
Antimicrobial and antioxidant properties of rosemary and sage (Rosmarinus officinalis L. and Salvia officinalis L., Lamiaceae) essential oils 总被引：2，自引：0，他引：2
Bozin B Mimica-Dukic N Samojlik I Jovin E 《Journal of agricultural and food chemistry》2007,55(19):7879-7885
The essential oils of rosemary ( Rosmarinus officinalis L.) and sage ( Salvia officinalis L.) were analyzed by means of gas chromatography-mass spectrometry and assayed for their antimicrobial and antioxidant activities. Antimicrobial activity was tested against 13 bacterial strains and 6 fungi, including Candida albicans and 5 dermatomycetes. The most important antibacterial activity of both essential oils was expressed on Escherichia coli, Salmonella typhi, S. enteritidis, and Shigella sonei. A significant rate of antifungal activity, especially of essential oil of rosemary, was also exhibited. Antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with the effect on lipid peroxidation (LP). RSC was assessed by measuring the scavenging activity of essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH) and hydroxyl radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H2O2 systems of induction. Investigated essential oils reduced the DPPH radical formation (IC50 = 3.82 microg/mL for rosemary and 1.78 microg/mL for sage) in a dose-dependent manner. Strong inhibition of LP in both systems of induction was especially observed for the essential oil of rosemary. 相似文献