辣椒碱新同系物的合成、表征及辣构关系的初步探讨

合成了两种辣椒碱同系物的新成员:反-N-(4-羟基-3-甲氧基苄基)-8-甲基-4-壬烯酰胺和N-(4-羟基-3-甲氧基苄基)-3,7-二甲基-6-辛烯酰胺,并用元素分析,FT-IR,1H NMR,13C NMR等方法对其结构进行了表征,还用斯科维尔感官评定的方法对其辣度进行了测定,分别为1.2×107和3.0×106SHU.并将它们的结构和辣度与辣椒碱、降辣椒碱和高辣椒碱进行了对比,总结出影响辣椒碱同系物辣度的结构因子为脂酰基双键的位置、脂酰基主链的长度及支链.     

干辣椒及制品中辣椒碱含量分析与辣度分级

采用高效液相色谱技术测定干辣椒及其制品中辣椒碱类物质的含量,计算出辣度,并对8个品种的干辣椒和26种干辣椒制品的辣度进行了评价。结果表明,仅根据辣椒碱和二氢辣椒碱的含量并不能正确区分干辣椒品种间的差异;根据Scoville指数将辣椒及其制品辣度分为5级,并在包装上用不同颜色区分。该分级方法可对辣椒及其制品进行有效的分级,并使消费者更直观的对辣椒产品进行选择。     

绿色海洋防污涂料技术及其研究进展

海洋生物污损给人类海洋生产和运输活动带来了严重的影响,涂覆防污涂料是解决这一问题根本办法。近年来大量使用的有机锡和氧化亚铜涂料,对海洋生物的生存环境造成了危害。因此,研究高效、低毒、绿色的海洋防污涂料成为目前发展的主要方向。本文综述了当前绿色环保型防污涂料的发展状况及研究进展,重点介绍了含氟、含硅低表面能防污涂料、天然产物防污涂料和新型无锡自抛光防污涂料的发展状况,并分析了今后绿色海洋防污涂料的发展趋势。     

高效液相色谱法测定辣椒中的辣椒碱和二氢辣椒碱

建立了高效液相色谱法(HPLC)测定辣椒中辣椒碱、二氢辣椒碱的检测方法.实验考察了仪器条件、不同流动相体系、流动相配比、柱温、流速等因素对分离的影响.确定了最佳色谱条件为ZORBAX SB-C18色谱柱(250mm×4.6 mm,5μm);二极管阵列检测器,辣椒碱、二氢辣椒碱的最佳检测波长为280 nm;色谱柱温度为2...     

具类辣素结构丙烯酰胺的合成及其抑菌和防污性能

以N-羟甲基丙烯酰胺和苯酚类化合物为原料,合成了N-(2-羟基-3-丙烯酰胺甲基-4,6-二甲基苄基)丙烯酰胺(HMABA)、N-(2-羟基-3-丙烯酰胺甲基-4,5-二甲基苄基)丙烯酰胺(AMHBA)、N-(3,5-二甲基-4-羟基苄基)丙烯酰胺(MHBA)、N-(3,6-二甲基-4-丙烯酰胺甲基-2-羟基苄基)丙烯酰胺(MAHBA)和N-(2甲氧基-4-甲基-5-丙烯酰胺甲基苄基)丙烯酰胺(MMABA)5个类辣素结构的丙烯酰胺衍生物。 通过红外光谱（IR）、核磁波谱（1H NMR）、质谱（HR-MS）和元素分析对化合物的结构进行了表征。 抑菌试验表明,HMABA对金黄色葡萄球菌和大肠杆菌的抑制效果最好,最低抑菌浓度均可达0.125 g/L。 将此5个化合物作为防污剂制备海洋防污涂料,120 d的实海结果表明,基本无污损海生物附着。     

海洋防污高分子材料的综合设计和研究

综述了海洋防污高分子材料与技术的发展现状.简介了海洋生物污损的形成过程,概述了杀生防污涂料、污损可脱附性涂层、阻止附着型防污技术以及其它现存的防污方法,并在此基础上提出了一种新的海洋防污高分子材料的综合设计方案,最后展示了有关海洋防污材料研究的最新成果.     

包埋苯甲酸钠微球的制备及在海洋防污涂料中的抑菌研究

用溶剂挥发法制备了可以包埋海洋防污剂苯甲酸钠的聚苯乙烯聚合物微球,并实现了防污剂在海洋防污涂料中的的缓慢释放.讨论了影响微球性能的一些因素,聚合物微球的粒径分别随着温度的降低,分散剂浓度的升高以及搅拌速度的提高而减小.采用标准曲线法,对防污剂释放速度进行了分析,并与未用微球包埋的苯甲酸钠释放速度进行对比,缓释效果明显....     

辣素衍生物的合成及其对新月菱形藻生长的抑制活性

通过对辣素结构分析,设计合成了9种辣素衍生丙烯酰胺单体,分析了它们的产率和熔点。并通过FTIR、NMR测试技术进行了结构表征和确认。其中有7种化合物是新化合物。室内生物学实验初步证明,所合成的辣素衍生丙烯酰胺单体对新月菱形藻生长均显示一定的抑制活性,,其大小为HDMBA>DMBA≈BMA>TMBA≈HMTBA>CHBA>HMMBA>BHBA>HMBA。     

叔胺铜离子络合物的表征及在铜离子缓释防污涂料中的应用

以五水合硫酸铜和甲基丙烯酸N,N-二甲基氨基乙酯为原料得到络合物,并利用傅里叶红外光谱及核磁共振谱对络合物进行表征.结果表明,铜离子与叔胺基发生配位,测定甲醇溶液中的电导率验证其最大配位数为4.形成的络合物对金属离子的释放具有缓释作用.合成了一系列甲基丙烯酸N,N-二甲基氨基乙酯无规共聚物涂料,结果表明,加入甲基丙烯酸N,N-二甲基氨基乙酯使涂料具有更好的抗菌性能且有助于延长其防污性能.     

超高效液相色谱法快速测定辣椒素类物质

建立了超高效液相色谱法快速测定辣椒制品中辣椒素、二氢辣椒素、降二氢辣椒素的方法.样品以四氢呋喃-甲醇(体积比1:1)提取,采用反相高效液相色谱分离.色谱柱为BEH C18,流动相乙腈-水进行梯度洗脱;二极管阵列检测器(DAD),检测波长为280 nm.各成分在1.0 -100.0 mL/L范围内线性良好.辣椒素、二氢辣...     

Studies on the synthesis, pungency and anti-biofouling performance of capsaicin analogues

Ten capsaicin analogues were synthesized and their pungency degrees were determined through Scoville Organoleptic Test.The relationship between the structure and pungency degree of these capsaicin analogues was discussed.Then four of these capsaicin analogues with higher pungency degree were picked out and added to anti-biofouling paints as repellents to study their anti-biofouling performance by shallow sea buoyant raft hung-plate experimentation.The results showed that capsaicin and dihydrocapsaicin exhibited equally good anti-biofouling performance while nordihydrocapsaicin and N-vanillylnonanamide had poor anti-biofouling performance.Experimental results also showed that the paints with only 0.1% capsaicin or dihydrocapsaicin as repellent without any other biocides had also exhibited good anti-biofouling performance,which provided a new idea for developing novel,more environment-friendly and Cu2O-free antifouling paints.     

Determination of capsaicin and dihydrocapsaicin in Capsicum fruit samples using high performance liquid chromatography

The aim of the present study was to determine the content of capsaicin and dihydrocapsaicin in Capsicum samples collected from city markets in Riyadh (Saudi Arabia), calculate their pungency in Scoville heat units (SHU) and evaluate the average daily intake of capsaicin for the population of Riyadh. The investigated samples consisted of hot chillies, red chillies, green chillies, green peppers, red peppers and yellow peppers. Extraction of capsaicinoids was done using ethanol as solvent, while high performance liquid chromatography (HPLC) was used for separation, identification and quantitation of the components. The limit of detection (LOD) of the method was 0.09 and 0.10 μg/g for capsaicin and dihydrocapsaicin, respectively, while the limit of quantification (LOQ) was 0.30 and 0.36 μg/g for capsaicin and dihydrocapsaicin, respectively. Hot chillies showed the highest concentration of capsaicin (4249.0 ± 190.3 μg/g) and the highest pungency level (67984.60 SHU), whereas green peppers had the lowest detected concentration (1.0 ± 0.9 μg/g); green peppers, red peppers and yellow peppers were non pungent. The mean consumption of peppers for Riyadh city population was determined to be 15.5 g/person/day while the daily capsaicin intake was 7.584 mg/person/day.     

Die Skala des Wilbur Lincoln Scoville. Manche mögen's scharf

All species of the genus capsicum are very popular food ingredients in most parts of the world. The biochemistry of Bell Pepper and Chili has many surprises to offer. The brilliant red color is based on the “paprika ketones, " compounds that only capsicum can synthesize. The extraordinary pungency, which many humans enjoy so much, is due to capsaicin and dihydrocapsaicin, which are also compounds that only capsicum can produce. After analyzing capsicums' unique and outstanding chemistry, we should enjoy peppers, chilis, Jalapeños, and Habaneros definitely with more respect because of their chemical achievements.     

Molecularly imprinted polymers with synthetic dummy templates for the preparation of capsaicin and dihydrocapsaicin from chili peppers

In this work, dummy molecularly imprinted polymers with high selectivity and affinity to capsaicin and dihydrocapsaicin are designed using N‐vanillylnonanamide as a dummy template. The performance of dummy molecularly imprinted polymers and nonimprinted polymers was evaluated using adsorption isotherms, adsorption kinetics, and selective recognition capacity. Dummy molecularly imprinted polymers were found to exhibit good site accessibility, taking just 20 min to achieve adsorption equilibrium; they were also highly selective toward capsaicin and dihydrocapsaicin. We successfully used dummy molecularly imprinted polymers as a specific sorbent for selectively enriching capsaicin and dihydrocapsaicin from chili pepper samples. In a scaled‐up experiment, the selective recovery of capsaicinoids was calculated to be 77.8% using solid‐phase extraction. To the best of our knowledge, this is the first example of the use of N‐vanillylnonanamide as a dummy template in molecularly imprinted polymers to simultaneously enrich capsaicin and dihydrocapsaicin.     

Preparative separation of capsaicin and dihydrocapsaicin from Capsicum frutescens by high‐speed counter‐current chromatography

Capsaicin and dihydrocapsaicin are two main bioactive components of Capsicum frutescens and are widely used as food additives and drugs in China and India. Due to their similarity in structures, isolation of capsaicin and dihydrocapsaicin with traditional methods such as silica gel column chromatography, normal‐phase thin‐layer chromatography (TLC) becomes difficult. This study involves separating capsaicin and dihydrocapsaicin with sufficient purity and recovery using high‐speed counter‐current chromatography (HSCCC) with a solvent system composed of n‐hexane–ethyl acetate–methanol–water–acetic acid (20:20:20:20:2, v/v/v/v/v). Separation parameters such as sample volume, and sample concentration were first optimized on analytical HSCCC, and then scaled up to preparative HSCCC. 0.65 g capsaicin and 0.28 g dihydrocapsaicin were obtained from 1.2 g crude extract and their purities were 98.5 and 97.8%, respectively. The recoveries of the two compounds were 86.3 and 85.4%, respectively. The purity of the isolated compounds was analyzed by high‐performance liquid chromatography (HPLC) and their structures were identified by ¹H nuclear magnetic resonance (NMR) and ¹³C NMR analysis.     

Peptide dendrimer-crosslinked inorganic-organic hybrid supramolecular hydrogel for efficient anti-biofouling

A novel kind of inorganic-organic hybrid supramolecular hydrogel with excellent anti-biofouling capability was developed. The hydrogel was formed via ionic interaction between the negative-charged sodium polyacrylate (SPA) entwined clay nanosheets (CNS) and positive-charged polyhedral oligomeric silsesquioxane (POSS) core-based generation one (L-Arginine) dendrimer (POSS-R).     

Green approach to the extraction of major capsaicinoids from habanero pepper using near-infrared,microwave, ultrasound and Soxhlet methods,a comparative study

A simple method for the extraction of two major capsaicinoids from habanero peppers, using near-infrared irradiation, microwave irradiation or ultrasound as the energy source and ethanol as the solvent, was compared with Soxhlet extraction. The extraction processes were monitored by gas chromatography/mass spectrometry. The new processes offer better overall yields and a higher ratio of capsaicin to dihydrocapsaicin than Soxhlet extraction. The physical effect of the different energy sources on the peppers was determined using scanning electron microscopy. Extraction of capsaicin and dihydrocapsaicin using near-infrared irradiation, which has not been previously reported, was shown to be a simple and efficient alternative extraction procedure.