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主要探究卵磷脂的抗氧化作用,通过采用水杨酸法、DPPH法、连苯三酚自氧化法分别测定卵磷脂对羟基自由基(·OH)、DPPH自由基(DPPH·)、超氧阴离子(O_2~-·)的清除作用。结果表明:在2~20 mg/mL浓度范围内,随着卵磷脂样品含量的增加,自由基清除率也增加。在20 mg/mL时,对·OH和DPPH·的清除率高达93. 38%和69. 72%,在10 mg/mL时,对O_2~-·的清除率为65. 3%。相同条件下,标准VC(1 mg/mL)对·OH、DPPH·的清除率分别为91. 20%、96. 18%。由此可知:卵磷脂对·OH、DPPH·、O_2~-·都有良好的清除作用 相似文献
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本文对天然香料的抗氧化性、主要抗氧化成分、制取方法、种类和使用等进行了阐述。实验结果表明,天然香料的某些性能优于BHA、BHT或VE,天然香料是食品等的优良抗氧化剂。 相似文献
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采用DPPH法对浓度范围为50~500μg/mL七组浓度下的木质素磺酸钠水溶液和浓度范围为50~300μg/mL六组浓度下的碱木质素水溶液的抗氧化性进行了研究,绘制了两种木质素与DPPH的反应动力学曲线。研究结果表明:浓度为400μg/mL的木质素磺酸钠与其他浓度的木质素磺酸钠水溶液相比,对DPPH清除能力最强,反应终止时,对DPPH的清除率达97.4%;浓度为200μg/mL和250μg/mL的碱木质素对DPPH的清除能力相当,且高于其他浓度,反应终止时,对DPPH的清除率分别为93.9%和94.6%。 相似文献
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天然香料的抗氧化性研究 总被引:2,自引:0,他引:2
本文对天然香料的抗氧化性、主要抗氧化成分、制取方法、种类和使用等进行了阐述。实验结果表明,天然香料的某些性能优于BHA、BHT或VE,天然香料是食品等的优良抗氧化剂。 相似文献
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文章以广西宜州废蚕丝为原料,探讨了丝素蛋白酶法水解产物的抗氧化活性.结果显示,丝素蛋白溶液在酶解3.5小时,对二苯代苦味酰基(DPPH·)和羟基自由基(·OH)的清除率达最佳,分别为35.24%和60.59%;对超氧自由基(O2-·)的清除率在4小时达到最佳,为25.37%.丝素蛋白的酶解产物具有良好的抗氧化活性. 相似文献
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文章以广西宜州废蚕丝为原料,探讨了丝素蛋白酶法水解产物的抗氧化活性。结果显示,丝素蛋白溶液在酶解3.5小时,对二苯代苦味酰基(DPPH·)和羟基自由基(·OH)的清除率达最佳,分别为35.24%和60.59%;对超氧自由基(O2-·)的清除率在4小时达到最佳,为25.37%。丝素蛋白的酶解产物具有良好的抗氧化活性。 相似文献
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以离体培养的百里香不定芽为材料,研究了培养基添加不同浓度的苯丙氨酸(phenylalanine,Ple)或茉莉酸甲酯(methyl jasmonate,MJ)对不定芽生长以及精油提取率等的影响。结果发现添加供试浓度的Ple和MJ都能不同程度促进不定芽的增殖,其中以添加100 mg/L Ple和150μmol/L MJ增殖效果最佳,增殖系数分别比对照显著增加47.03%和23.57%。采用水蒸气蒸馏法提取了普通百里香(Thymus vulgaris L.)组培苗、以及培养基添加苯丙氨酸或茉莉酸甲酯的普通百里香[0]组培苗的精油,添加100 mg/L Ple和150μmol/L MJ的提取率分别为0.42%和0.39%,分别比对照(0.31%)增加了35.5%和25.8%。利用气质联用法(GC-MS)并结合色谱峰面积归一化法对其化学成分和相对含量进行了比较研究,3种组培苗百里香精油的主要化学成分无明显的差异,都含有百里香精油的主要成分百里香酚、香芹酚、邻-伞花烃、γ-松油烯、石竹烯等,只是相对含量略有差异。研究表明,适宜浓度的苯丙氨酸和茉莉酸甲酯不仅提高了百里香不定芽的增殖系数,改善了植株的生理活性,而且还促进了百里香次生代谢产物的积累和合成。 相似文献
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Bela Simandi V. Hajdu K. Peredi B. Czukor A. Nobik‐Kovacs A. Kery 《European Journal of Lipid Science and Technology》2001,103(6):355-358
Leaves and flowering tops of thyme (Thymus vulgaris L.) were extracted with ethyl alcohol and supercritical carbon dioxide. Antioxidant activity was measured in sunflower oil at 0.3, 0.6 and 1% concentrations of extracts by oven test and Rancimat method. The activities of extracts were compared to those of butylated hydroxytoluene at 0.01 and 0.1% level. The ethanolic extract showed a slightly higher antioxidative effect than that obtained by supercritical fluid extraction. The effectiveness of both extracts added at 0.6% level were equal to that of 0.1% of butylated hydroxytoluene. 相似文献
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唇形科植物夏枯草Prunella vulgaris L.的干燥果穗是中国药典收载的常用中药。其清肝泻火,明目,散结消肿,常用于目赤肿痛,头痛眩晕乳房胀痛等症状。本文通过查阅文献对夏枯草的指纹图谱的研究现状进行了综述,从而为其质量控制的深入研究提供参考。 相似文献
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欧洲迷迭香的研究状况 总被引:9,自引:0,他引:9
综述了迷迭香在欧洲特别是英国、法国、德国、西班牙、意大利和瑞士等国的发展状况,内容涉及迷迭香的科研、标准、种植、加工、应用和贸易等方面情况。 相似文献
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用ICAP测定了紫丁香等三种丁香叶中18种元素,发现所含元素种类基本相同.但不同种类丁香叶的各种元素含量却有差异.这提示研究中草药药效时应对元素,尤其是微量元素之间含量的差异予以注意. 相似文献
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Rui L. Mendes Jos P. Coelho Helena L. Fernandes Isabel J. Marrucho Joaquim M. S. Cabral Júlio M. Novais Antanio F. Palavra 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,62(1):53-59
A flow apparatus was constructed to carry out studies of supercritical fluid extraction in the temperature range 298·15–353·15 K and pressures up to 40 MPa. To test the apparatus, studies on the solubility of naphthalene in CO2 at 308·15, 313·15 and 318·15 K and pressures up to 35 MPa were carried out. These experimental data were correlated through the Peng–Robinson equation of state. Samples of the microalgae Botryococcus braunii and Chlorella vulgaris which produce diolefines C25–C31 and carotenoids, respectively, were submitted to supercritical CO2. The extraction yields for these compounds were studied and compared with those obtained using organic solvents. Supercritical CO2 was also used to produce extracts from rosemary leaves (Rosmarinus officinalis L.), which were compared with those obtained by hexane extraction. 相似文献
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Shu Wang Xiang-Qian Liu Ok-Hwa Kang Dong-Yeul Kwon 《International journal of molecular sciences》2022,23(8)
Methicillin-resistant Staphylococcus aureus (MRSA) infection is challenging to eradicate because of antibiotic resistance and biofilm formation. Novel antimicrobial agents and alternative therapies are urgently needed. This study aimed to evaluate the synergy of sanguisorbigenin (SGB) isolated from Sanguisorba officinalis L. with six conventional antibiotics to achieve broad-spectrum antibacterial action and prevent the development of resistance. A checkerboard dilution test and time-to-kill curve assay were used to determine the synergistic effect of SGB combined with antibiotics against MRSA. SGB showed significant synergy with antibiotics and reduced the minimum inhibitory concentration of antibiotics by 2–16-fold. Biofilm inhibition assay, quantitative RT-PCR, crystal violet absorption, and transmission electron microscopy were performed to evaluate the synergy mechanism. The results indicated that SGB could inhibit biofilm formation and alter cell membrane permeability in MRSA. In addition, SGB was found to exhibit quite low cytotoxicity and hemolysis. The discovery of the superiority of SGB suggests that SGB may be an antibiotic adjuvant for use in combination therapy and as a plant-derived antibacterial agent targeting biofilms. 相似文献
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迷迭香化学成分研究 总被引:1,自引:0,他引:1
为研究迷迭香的化学成分,采用溶剂w(CH3CH2OH)=95%热浸法提取,再依次用石油醚、乙酸乙酯、正丁醇萃取,采用正相硅胶,C-18,Sephadex-20柱层析等方法,进行了分离纯化,共分离得到7个化合物。根据化学方法结合波谱分析数据(1D-NMR,2D-NMR)对分离所得化合物进行了结构鉴定,确定7个化合物分别是:迷迭香酚rosmanol(Ⅰ)、桦木酸(betulinicacid)(Ⅱ)、桦木醇betulin(Ⅲ)、7,24-tirucalladien-3β,27-diol(Ⅳ)、tirucalla-7,24-dien-3β,21,23-triol(Ⅴ)、迷迭香醌(rosmanol quinone)(Ⅵ)、芫花素(genkwanin)(Ⅶ),从迷迭香中分离得到的化合物Ⅳ、Ⅴ,鲜见文献报道。 相似文献