Effects of extraction temperature on the phenolic and parthenolide contents,and colour of aqueous feverfew (Tanacetum parthenium) extracts

The aim of this study was to determine the effects of extraction temperature on the colour as well as on the phenolic and parthenolide content of feverfew (Tanacetum parthenium) aqueous extracts, with a view to incorporating the extracts into a beverage. Results showed that extraction temperatures of 20–70 °C yielded dark-coloured extracts with low total phenol and a relatively high total tannin concentration. However, increasing the temperature to 75 °C produced lighter-coloured extracts with a significantly higher concentration of total phenols, lower total tannin fraction and maximum extraction of parthenolide. Higher extraction temperatures (80–100 °C) yielded suitably pale extracts rich in total phenols, but with progressively higher total tannin to non-tannin ratio and lower parthenolide content. The compromise temperature of 80 °C was found to provide extracts rich in parthenolide content, phenolic content and with a desirable colour, suitable for incorporation into a functional beverage.     

Environmentally friendly phthalocyanine catalysts for water decontamination—Non-photocatalytic systems

Macrocyclic porphyrin-like compounds known as phthalocyanines (Pcs) have been shown to produce singlet oxygen species upon illumination with light of an appropriate wavelength. Singlet oxygen is an effective agent for complete oxidation of common water-soluble pollutants including chlorinated phenols. The most active are, in this respect, phthalocyanines bearing Al, Zn and Si central atoms. Although these compounds were proofed to be virtually non-toxic, the presence of the Al³⁺ and Zn²⁺ ions may contradict this. On the other hand e.g. iron phthalocyanine (FePc) does not represent any danger from this point of view. However, due to the specific coordination of its central metal ion and also because of the number of electrons occupying its valence orbitals, the FePc cannot be effectively activated by the photon flux. Here we report on an alternative system in the dark. It is based on the initial catalytic decomposition of various peroxo substances by metal Pc, producing oxidising species which can decompose chlorinated phenols. A series of Pcs and peroxo substances were compared and the reaction system optimised. It was shown that the highest activity was revealed for the system comprising of FePc and tert-butylhydroperoxide. Iron phthalocyanine was also successfully immobilised on an Al₂O₃ solid matrix, and this heterogeneous system was tested analogously to the homogeneous one. Virtually zero leaching of the anchored complex was detected and the activity was found to be comfortably high.     

Chemically mediated behavior in Acari: Adapations for finding hosts and mates

Ticks and mites respond to a limited spectrum of stimuli in their search for hosts and mates. Airborne chemical signals include carbon dioxide, ammonia, organic acids, terpenoids, 2,6-dichlorophenol, and other phenolic compounds. These are detected primarily by sensilla in and adjacent to Haller's organ. Most ixodid species examined have one or more multiporose sensilla that detect such volatiles. These olfactoreceptors enable the ticks to respond to remote volatile chemicals from hosts and from the other ticks, e.g., sex pheromones. Other sensilla, probably mechanogustatory in function, also occur on the tarsi. Gustatory sensilla on the palps detect assembly pheromones that enable ticks and mites to respond to conspecific or heterospecific chemical stimuli in their environment. Responses to those stimuli in ticks result in clustering, i.e., arrestant behavior. Arrestant behavior also occurs in certain mites. Finally, cheliceral chemosensilla enable ticks to recognize specific phagostimulants in host blood, e.g., ATP and glutathione, that stimulate feeding. InDennacentor variabilis andD. andersoni, these same cheliceral chemosensilla recognize species-specific genital sex pheromones in the vulvae of conspecific mates, without which they do not copulate.     

卤代酚对水生梨形四膜虫急锐毒性的QSAR研究

应用HyperChem7．O计算与卤代苯酚对水生四膜虫毒性相关的量化参数以及自己设计的结构编码参数,对31种卤代酚的毒性做QSAR研究。使用逐步回归筛选出影响卤代苯酚毒性的主要参数分子表面积S、分子体积ν和编码参数R3和R6建立QSAR方程。用留一法验证该模型,检验结果相关系数R为0．9496,标准偏差s为0．2606,与回归拟合得到的R=O．9686,s =0．2067十分接近,表明所建立的QSAR方程具有较好的预测效果和较高的预测稳定性。对QSAR方程各参数对卤代苯酚毒性的影响分析表明,S、ν影响卤代酚的基本毒性,R6影响极性麻醉,而R3则既与卤代酚基本毒性有关,也与极性麻醉有关。     

我国给水内分泌干扰物问题

文章介绍了内分泌干扰物的危害,内分泌干扰物的分类,我国给水中内分泌干扰物的污染现状以及给水工作中有关内分泌干扰物的问题。     

苯酚和苯胺类化合物对大型蚤毒性的QSAR

基于DFT-B3LYP方法在6-311G**基组水平上计算获得了36种苯酚和苯胺类化合物的量化和理化参数,采用最佳变量子集回归方法,建立苯酚和苯胺类化合物对大型蚤毒性与上述描述符参数的定量构效关系。结果表明所建三变量模型具有良好的预报能力和稳健性,化合物次最低空轨道能愈小,毒性愈大;化合物疏水性愈强,毒性愈大;化合物偶极距愈小,毒性愈强。     

茴香中总多酚和总黄酮含量及其抗氧化活性研究

测定茴香体外抗氧化活性,并分析茴香中总多酚与总黄酮含量与抗氧化活性的关系。结果表明,茴香乙酸乙酯部位和正丁醇部位具有体外抗氧化活性。其中,乙酸乙酯部位清除DPPH自由基和ABTS+自由基的能力（IC50分别为（37.67±0.21）、（24.88±0.07）μg/mL）比正丁醇部位的清除能力（IC50分别为（47.48±0.18）、（34.19±0.19）μg/mL）强,且具有显著性差异（p<0.05）,而正丁醇部位对铁离子的还原能力（TEAC值为（569.9±0.69）μmol/g）比乙酸乙酯部位的还原能力（TEAC值为（281.23±4.73）μmol/g）强,且具有显著性差异（p<0.05）。乙酸乙酯部位清除DPPH和ABTS自由基的能力强可能与其总黄酮含量高有关,正丁醇部位还原铁离子的能力好与其总多酚含量高有关。      

不同品种杭白菊中酚类物质含量和清除自由基活性的比较

4种酮乡产杭白菊及黄菊和野菊,分别用乙醇-水体系进行热回流提取,用比色法测定醇提物中总酚和总黄酮含量,并用化学发光法检测春清除活性氧自由基的能力。结果表明,不同品种间含量存在较大差异,总酚和总黄酮含量（以菊花干基计）最高提异种大白菊,分别为9.76%和4.46%;最低的是黄山种野菊,分别为3.21%和1.99%。不同菊花均显示了良好的清除活性氧自由基的活性,清.OH和O2^.-的IC50分别在0.54-1.98mg/ml和24.2-54.5ug/ml之间,其中清O2^.-活性最强是大洋菊,最弱是软梗小洋菊;而清.OH能力最强为早小洋菊,最终为异种大白菊,结果表明,菊花中酚类物质的含量高低与抗自由基活性强弱无明显的对应关系。     

离子液体-分子溶剂复合萃取剂脱除水中酚类化合物

构建了疏水性离子液体-分子溶剂复合萃取剂,并研究了其对酚类化合物的萃取性能。结果表明,与纯离子液体萃取剂相比,三己基十四烷基溴化（[P₆₆₆₁₄]Br）-乙酸乙酯复合萃取剂在显著降低萃取剂黏度的同时,获得了较高的酚类溶质分配系数。当萃取剂中[P₆₆₆₁₄]Br摩尔分数为20%时,苯酚的分配系数为345,是纯乙酸乙酯为萃取剂时的5.3倍,是[omim]BF₄、[C₁₂mim]NTf₂等常规疏水离子液体的9~60倍;比纯[P₆₆₆₁₄]Br为萃取剂时的分配系数下降25.3%,黏度却比纯[P₆₆₆₁₄]Br降低99%以上。COSMO-RS研究表明[P₆₆₆₁₄]Br与苯酚之间较强的氢键作用是获得较高苯酚分配系数的关键因素。该复合萃取剂对间苯三酚、4-氯苯酚和2,5-二硝基苯酚等物质也有良好的萃取能力。上述结果为开发兼具良好热力学性能和动力学性能的脱酚萃取剂提供了新的思路。     

不同品种桑椹酒抗氧化能力及其多酚含量分析

对6个不同品种的桑椹酒的总酚、总类黄酮、原花青素、总花色苷及桑椹酒中主要的两种花色苷（矢车菊-3-氧-芸香糖苷和矢车菊-3-氧-葡萄糖苷）的总抗氧化能力及其相关性进行了分析.结果表明,不同品种的总酚、总类黄酮、原花青素、总花色苷、矢车菊-3-氧-葡萄糖苷、矢车菊-3-氧-芸香糖苷和总抗氧化能力变幅和变异系数较大,存在显著差异（P＜0.05）;桑椹酒总抗氧化能力与总酚、总类黄酮、原花青素、总花色苷及矢车菊-3-氧-葡萄糖苷和矢车菊-3-氧-芸香糖苷含量之间存在正相关性,其中与总酚的相关性最强,达到0.917 2.