阴离子交换树脂吸附辣椒碱的动力学研究

以辣椒树脂为原料,采用静态吸附法确定了201×7型阴离子交换树脂吸附辣椒碱的最优工艺和提取机理。通过可见分光光度法测定了辣椒碱的质量浓度,并绘制出了不同pH的吸附等温线,建立了离子交换吸附辣椒碱的动力学模型。实验结果表明:该树脂吸附辣椒碱的最优pH值为5.5,当pH5.0或pH6.0时,Langmuir方程能够更好地拟合该吸附过程;而当pH=5.0~6.0时,辣椒碱的吸附等温线更符合Freundlich方程。在pH=5.5、308.15K下,较高的辣椒树脂的质量浓度能显著提高离子交换速率,且初期(t30 min)800~1200r/min的搅拌速率有利于吸附过程。通过计算得出,树脂吸附辣椒碱模型的速率常数k0=2.11×10-3s-1、活化能Ea=12.6 k J/mol、反应级数为0.268,并利用Freundlich模型解析获得了最优pH值(5.5)下阴离子交换树脂吸附辣椒碱的动力学方程。     

Anti-proliferative activities,phytochemical levels and fruit quality of pepper (Capsicum spp.) following prolonged storage

Peppers are rich in health-promoting phytochemicals, which are involved in the defence mechanisms against cancer. To select a lead variety of pepper with anti-proliferative activity against colon cancer cells and liver cancer cells, high antioxidant activity, and high concentrations of capsaicin, flavonoids and phenolics, we compared these attributes in nine different pepper accessions belonging to Capsicum annuum and C. chinense. Quality parameters such as weight loss and total soluble solids content were tested as well. The different parameters were determined immediately after harvest and after prolonged storage and marketing simulation. A significant variation of these traits was detected among the accessions. C. chinense line 1745 had the highest antioxidant activity, the highest levels of capsaicin and flavonoids, a high and specific anti-cancer activity, and the lowest weight loss level during postharvest storage. It is proposed that line 1745 has potential for use as a source for health-promoting traits and should be further evaluated for use as a nutraceutical for the prevention and treatment of colon and liver cancers.     

Binding Mode Prediction of Evodiamine within Vanilloid Receptor TRPV1

Accurate assessment of the potential binding mode of drugs is crucial to computer-aided drug design paradigms. It has been reported that evodiamine acts as an agonist of the vanilloid receptor Transient receptor potential vanilloid-1 (TRPV1). However, the precise interaction between evodiamine and TRPV1 was still not fully understood. In this perspective, the homology models of TRPV1 were generated using the crystal structure of the voltage-dependent shaker family K(+) channel as a template. We then performed docking and molecular dynamics simulation to gain a better understanding of the probable binding modes of evodiamine within the TRPV1 binding pocket. There are no significant interspecies differences in evodiamine binding in rat, human and rabbit TRPV1 models. Pharmacophore modeling further provided confidence for the validity of the docking studies. This study is the first to shed light on the structural determinants required for the interaction between TRPV1 and evodiamine, and gives new suggestions for the rational design of novel TRPV1 ligands.     

The Preparation of Capsaicin-Chitosan Microspheres (CCMS) Enteric Coated Tablets

This study aimed to research the preparation and content determination of capsaicin-chitosan microspheres (CCMS) enteric coated tablets. The core tablets were prepared with the method of wet granulation. Nine formulae were designed to determine the optimal formula of the core tablet. Eudragit L100 was used to prepare the CCMS enteric-coated tablets. The effect of enteric coated formulation variables such as content of talc (10%, 25% and 40%), plasticisers (TEC and DBS), dosage of plasticiser (10%, 20% and 30%) and coating weight (2%, 3% and 5%) were evaluated for drug release characteristics. The in vitro release was studied using 0.1 N HCl and pH 6.8 phosphate buffer. Enteric coated tablets without ruptures or swelling behaviour over 2 h in 0.1 N HCl indicated that these tablets showed acid resistance. The accumulated release rate in phosphate buffer (pH 6.8) revealed that the prepared tablets were able to sustain drug release into the intestine and a first-order release was obtained for capsaicin. This research is the first report of the preparation and content determination of CCMS enteric coated tablets. The sustained release behavior of enteric coated formulations in pH 6.8 phosphate buffer demonstrated that it would be a potential drug delivery platform for sustained delivery of gastric irritant drugs.     

辣椒辣素的提取分离技术研究

根据辣椒辣味成分和色素尬发理化性质的不同，经过多次不同浓度、不同酸碱度溶剂的提取分离试验研究，确定了简便易行、安全有效地分离两类成分的技术工艺。     

氯化钠对猪肉肌原纤维蛋白构像及其与辣椒素相互作用的影响

摘要：目的探究氯化钠浓度对猪肉肌原纤维蛋白（Myofibrillar Proteins, MPs）与辣椒素（Capsaicin, CAP）相互作用的影响。方法 本实验选择0~0.9 mol/L的氯化钠处理MPs,然后与CAP在25℃进行反应,并采用粒度仪、SDS-PAGE、激光共聚焦显微拉曼光谱、荧光光谱分析了不同氯化钠浓度对MPs的结构以及MPs与CAP相互作用的影响。结果 MPs的溶解性及其在溶液中的稳定性随氯化钠浓度的增加而逐渐增强;SDS-PAGE表明,氯化钠浓度的改变,会引起MPs溶液中各种蛋白质分子组成的变化;氯化钠浓度的升高会增强MPs表面疏水性,并进一步促进了MPs与CAP的结合。拉曼光谱数据表明氯化钠的存在没有显著改变MPs的二级结构,同时,CAP与MPs结合不影响MPs的二级结构。荧光猝灭光谱数据表明：在不同氯化钠浓度下,CAP均能引起MPs的内源荧光产生静态猝灭;且随着氯化钠浓度的增加,MPs-CAP复合物的结合常数Kb值及n值均增大,表明氯化钠能够促进MPs与CAP的相互作用。结论 氯化钠浓度的增加能够提高MPs的溶解性、稳定性,不改变MPs的二级结构,能够通过增加MPs表面疏水性的方式促进MPs与CAP之间的相互作用。     

辣味感觉的产生及其调控机制研究进展

辣椒素类物质是辣椒果实中“辣味”的来源,辣椒素类物质通过刺激神经末梢,在神经末梢上和某些分子反应产生生物电脉冲,激活人体神经中的辣椒素受体通道,然后将信号传导到大脑,产生辣味感觉（以下简称辣味）。研究发现,辣味与味觉之间存在协同或抑制作用,不同浓度的辣椒素类物质与味觉的相互作用也不同,因此,本文对辣椒素类物质的种类、化学性质及应用进行概括,阐述辣味的产生,即辣椒素激活辣椒素受体通道的生物学机制,同时探讨辣味与酸味、甜味、苦味、咸味以及鲜味的相互作用,指出目前辣味与味觉相互作用及其潜在影响机制研究方面存在的不足,并展望未来的研究方向,以期为辣味产业的进一步发展提供理论支持。     

N-(2,3,4-三羟基-5-丙烯酰胺甲基苄基)丙烯酰胺的合成及性能研究

以联苯三酚和N-羟甲基丙烯酰胺为原料,通过傅-克烷基化反应,合成了含辣素衍生结构的丙烯酰胺类功能单体——N-(2,3,4-三羟基-5-丙烯酰胺甲基苄基)丙烯酰胺(AHMBA)。通过红外吸收光谱(FT-IR)、1H-NMR波谱和13C-NMR波谱对其结构进行了表征。初步研究了该化合物在海洋防污涂料中的防污性能。     

球磨法制备天然辣椒素粉体工艺研究

以天然辣椒素和硅胶为原料和辅料,采用球磨法制备天然辣椒素粉体,采用正交实验法,对球料质量比、天然辣椒素与硅胶的质量比、球磨时间、球磨机转速等参数进行4因素3水平的正交实验设计,研究这些工艺参数对球磨法制备天然辣椒素粉体的影响。结果表明,制备天然辣椒素粉体的最佳工艺为球料质量比为5∶1,天然辣椒素与硅胶的质量比为4∶6,球磨时间为20 min,转速为300 r/min,在此条件下,制备的天然辣椒素粉体中粒径小于10μm的颗粒的体积分数为94.98%。     

Perception of Heat in Cheese Sauces as Affected by Capsaicin Concentration, Fat Level, Fat Mimetic and Time

Perceived heat intensity in cheese sauces with five capsaicin levels, three fat levels and four fat mimetics was studied with time intensity techniques. Heat intensity was not related to fat mimetic. No differences occurred among fat levels at 0.0 and 0.4 ppm capsaicin. At 0.8 ppm capsaicin, maximum and total heat intensities of reduced- and low-fat sauces were equal; both were lower in full-fat sauces (P<0.001). Low-fat sauces exhibited greater maximum heat and total intensity than full-fat at 1.2 ppm capsaicin. At 1.6 ppm capsaicin, low-fat sauces had greater total intensity than either reduced-or full-fat (P<0.05) sauces. At low-fat levels, lower capsaicin concentrations provided heat equal to higher concentrations in full-fat cheese sauces.