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1.
Quantitative UPLC‐MS/MS analysis of chlorogenic acid derivatives in antioxidant fractionates from dandelion (Taraxacum officinale) root 下载免费PDF全文
Owen Kenny Thomas J. Smyth Chandralal M. Hewage Nigel P. Brunton 《International Journal of Food Science & Technology》2015,50(3):766-773
While qualitative studies have identified chlorogenic acids in antioxidant extracts, particularly ethyl acetate‐derived extracts, of Taraxacum officinale, quantitative analysis of these phenolic compounds remains largely unreported for this species. In this study, bioactivity‐guided fractionation of an antioxidant crude ethyl acetate extract (DPPH = 295.481 ± 0.955 mg TE g?1 extract) from T. officinale root resulted in a number of reverse‐phase fractions that demonstrated high antioxidant activity (DPPH = 1058.733–1312.136 mg TE g?1 extract), stronger than that of the synthetic antioxidant Trolox®. UPLC‐MS/MS screening of these fractions for the presence of selected mono‐ and di‐caffeoylquinic acids revealed large quantities of 1,5‐dicaffeoylquinic acid present in several fractions (853.052–907.324 μg mg?1), respectively. Due to the antioxidant potency and high levels of 1,5‐dicaffeoylquinic acid observed in these fractions, it was concluded that specifically this chlorogenic acid derivative is a major contributor to the antioxidant efficacy of dandelion root. 相似文献
2.
Juan Carlos Benítez Carlos A. Giúdice Vicente J. D. Rascio 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1985,35(8):387-394
This paper discusses the bioactivity of antifouling paints based on organotin toxicants, such as tributyltin fluoride (TBTF) and triphenyltin fluoride (TPTF). These compounds were used alone or mixed as the main toxicant in formulations. The use of TPTF or mixtures of TPTF and TBTF, with vinyl binders, led to paints with satisfactory bioactivity during a 24 months immersion period. With the same binders, TBTF alone provided only 12 months of antifouling protection. The correlation coefficients calculated from the fouling attachment values and the rosin content in the binder showed that the bioactivity of the tested formulations depended on the solubility of the toxicant in sea water and on the composition and solubility of the binders. 相似文献
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LIU Guangzhen MA Zhanfang SHEN Jianquan 《武汉理工大学学报(材料科学英文版)》2006,21(4):16-18
1 IntroductionGold nanoparticles have attracted considerable atten-tionin manyfields duetotheir some special properties al-though goldis very popularfor beingchemicallyinert[1-3].For example ,gold nanoparticles as amplificationtags havebeenthe subject of research directed at gene analysis[4]and antibody or antigen detection[5-7]due to the large di-electric constant ,ease of preparation,andits biocompati-bility[8].Nanoparticles in the range of 1-10 nmin diameterwould display electronic structur… 相似文献
5.
氟磷灰石-氟金云母微晶玻璃的生物活性研究 总被引:3,自引:0,他引:3
通过模拟细胞外液浸泡及动物骨内种植的方法研究了氟磷灰石-氟金云母微晶玻璃的生物活性机理。借助于SEM/EDAX,薄膜XRD,IRRS及原子吸收光谱分析等技术,研究了该微晶玻璃在生理环境中表面羟墓碘灰石层的形成过程。根据微晶玻璃中主晶相种类、显微结构特点及溶液中各离子的浓度等讨沦了羟基碑灰石层的形成机理。认为微晶玻璃中残余玻璃相的Ca~(2+)溶出及溶液相对于羟基磷灰石的过饱和状态,对材料表面羟基碑灰石层的形成具有重要意义。形成的羟基磷灰石层具有较低的结晶度,它是由最初的无定形态含水富CaO,P_2O_5薄层晶化转变而成。 相似文献
6.
杀虫植物的研究新进展及应用发展前景 总被引:13,自引:3,他引:13
介绍了近几年杀虫植物研究的新进展,主要包括楝科、卫矛科、豆科、菊科、胡椒科、百部科、瑞香科等科杀虫植物的作用方式和部分植物的有效成分与作用机制及杀虫植物的应用概况,并分析了其应用发展前景。 相似文献
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Tall oil, a by-product of the kraft process for pulping softwood, has been shown to have insecticidal properties. In the present study, the active principles in tall oil against the variegated cutworm,Peridroma saucia Hübner, were investigated. GC-MS analysis showed that abietic, dehydroabietic, and isopimaric acids were major resin acid components of crude tall oil and depitched tall oil. When crude tall oil samples of differing resin acid composition were incorporated into artificial diet at a concentration of 2.0% fresh weight, they suppressed larval growth by 45–60% compared to controls. This suppression was significantly (P0.05) correlated with the equivalent contents of abietic, dehydroabietic, isopimaric, and total resin acids. These results were also evident from a diet choice test, showing that the second-instar larvae obviously selected diets with low levels of resin acids when different diets were randomly arranged in a Petri dish. Bioassays with pure resin acids (abietic, dehydroabietic, and isopimaric acids) demonstrated that all individual chemicals have similar bioactivity against this insect. Comparison of the bioactivities of depitched tall oil and an equivalent mixture of pure resin acids in thePeridroma chronic growth bioassay indicated that pure resin acids and depitched tall oil share a common mode of action to this insect. This study confirms that resin acids are major active principles in tall oil against the variegated cutworm, but other chemicals likely also contribute to the bioactivity of tall oil. 相似文献
9.
为了研究脂肪醇结构-性质(活性)的定量关系,用相对键长取代拓扑距离,结合距离矩阵,提出了距离调和拓扑指数Te,Te和醇的许多理化性质和生物活性具有良好的相关性.用Te及δ(醇中和羟基相连的碳原子的支化度)与脂肪醇的溶解度、辛醇/水分配系数、急性生物毒性、蒸发热、摩尔磁化率关联,复相关系数分别为0.9955,0.9951,0.9941,0.9964,0.9968,优于文献.同时与脂肪醇的气相色谱保留指数也相关得很好,相关系数为0.9956.结果表明,Te指数可用于醇多种理化性质和生物活性的预测. 相似文献
10.
The bioactivity of mica/apatite glass ceramic composites, including the in vitro behavior in simulated body fluid and the histological appearance of the interface between the mica/apatite glass ceramics and the rabbit mandible defect in vivo under a dynamic condition. The results show that biological apatite layer forms on the surface of the mica/apatite glass ceramics after l d of immersion in the simulated body fluid, and becomes dense after 14 d. In vivo tests indicate that bone formation occurs after implantation for 14 d, and strong bonding of bone to the implant occurs after 42 d. No aseptic loosening occurs during 42 d of implantation. The finding shows that mica/apatite glass ceramics have good bioactivity and osteoconductivity for constructing bone graft, and can be promising for biomedical application. 相似文献