铂电极上异黄樟油和胡椒醛电氧化的SERS研究

采用循环伏安(CV)法和原位表面增强拉曼光谱(SERS)技术, 研究了非水体系中反应物异黄樟油和目标产物胡椒醛在粗糙铂电极上的电氧化行为, 发现胡椒醛在电位≥1.50 V时将进一步氧化, 而且从分子水平证实, 在胡椒醛的氧化电位(≥1.50 V) 下, 波长为632.8 nm的激光对胡椒醛的氧化有助催化作用. 由异黄樟油直接电氧化合成胡椒醛的电位(E)应控制在1.20 V相似文献   

Novel regulation of aflatoxin B1 biosynthesis in Aspergillus flavus by piperonal

The present study investigated its inhibitory role in aflatoxin (AF) biosynthesis. Treating only AFB1- and B2-producing Aspergillus flavus with piperonal completely inhibited AFB1 production with high sclerotial formation, resulting in 20-fold higher AFG2 production. On the other hand, benzodioxole and eugenol suppressed AFB1 production without AFG formation, while methyleugenol showed potent inhibition of AFB1 production with slight production of AFG1. These results indicate that natural products may change aflatoxin biosynthesis, and highlight a novel regulation of AFG2 production by piperonal. It is the first report for chemical regulation on AFG2 production in non-AFG producing-aspergilli.     

胡椒基荧光酮光度法测定粉煤灰中微量镓

在表面活性剂OP存在下,镓与胡椒基荧光酮(PIF)在pH 6.0 HAc-NaAc缓冲溶液中形成蓝紫色配合物,其表观摩尔吸光系数为8.51×104L.mol-1.cm-1,最大吸收波长为568 nm,配合物的组成比为n(Ga(Ⅲ))∶n(PIF)=1∶4。镓质量浓度在0~0.5μg/mL范围内符合比耳定律,镓(Ⅲ)的标准加入回收率在96.5%~102.1%之间。结合乙酸丁酯萃取分离干扰元素,用于测定粉煤灰中微量镓。     

3-芳基异喹啉生物碱中间体的合成

以胡椒醛(6)和邻香草醛(1)为初始原料,共经过九步反应得到了合成3-芳基异喹啉生物碱的关键中间体1,2-二芳基乙酮(11),以胡椒醛为起始原料计算,总收率达50．4％     

铁(Ⅲ)的硅胶H相反射散射光度法研究

本文提出了胡椒基荧光酮 (PIF)硅胶H相反射散射光度法测定铁的新方法。在溴化十六烷基三甲基铵的存在下 ,PIF与铁 (Ⅲ )形成稳定的蓝色配合物并且能被硅胶H吸附 ,其最大反射散射吸收波长位于 6 4 0nm ,铁 (Ⅲ )的浓度在 0～ 2 5ng·mL- 1 范围内呈线性关系 ,方法用于氧化镁中微量铁的测定 ,结果满意。     

Efficient preparation of dichloromethyl alkyl ethers and their application in the formylation of aromatic compounds: Scope and limitations

Practical preparations of dichloromethyl alkyl ethers are described, based on the reaction of alkyl formates with oxalyl chloride in the presence of N-methylformanilide. The method involves a simple procedure that does not require the use of harmful reagents. Dichloromethyl propyl and dichloromethyl butyl ethers represent secure synthetic equivalents to dichloromethyl methyl ether. Formylations of both electron-deficient and electron-rich aromatics with these dichloromethyl alkyl ethers in the presence of AlCl₃, FeCl₃, or TiCl₄ have been systematically investigated. A plausible mechanism of formylation is discussed.     

新试剂洋茉莉基荧光酮与铁(Ⅲ)显色反应的研究及应用

本文提出了洋茉莉基荧光酮（ＰＩＦ）光度法测定铁的新方法。在溴代十六烷基吡啶存在下，ＰＩＦ与铁（Ⅲ）形成稳定的蓝色配合物，其最大吸收波长位于６３５ｎｍ。配合物中铁（Ⅲ）与ＰＩＦ的组成比为１∶２。铁的浓度在０．００—０．２４μｇ·ｍＬ－１呈线性关系。表观摩尔吸光系数ε６３５＝１．２６×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。方法用于某些化学试剂中微量铁的测定，结果满意。     

铜与洋茉莉基荧光酮反应的分光光度研究及应用

本文研究了在CPB存在下洋茉莉基荧光酮（PIF）与铜的显色反应。结果表明：在pH5.8-6.6的六次甲基四胺－HCl缓冲介质中，Cu^2 与PIF形成1：2的蓝紫色配合物，以524nm为参比波长、582nm为测定波长，用双波长吸光光度法测得表观摩尔吸光系数为1.11×10^5L·mol^-1·cm^-1。铜在0－0.20μg/mL范围内服从比耳定律。用于高纯稀土氧化物中微量铜的测定，相对误差不大于3.7%，相对标准偏差不大于2.0%（n=6）。     

2—甲基—6,7—亚甲二氧基—3—喹啉酸乙酯的合成

以胡椒醛为原料，经硝化、还原、缩合、制备了标题化合物，产率８０％。     

Adsorbed resin phase spectrophotometric determination of vanillin or/and its derivatives

The reactive mechanism, stability and interrelating properties, and thermodynamic constants of β-cyclodextrin polymer (β-CDP) including vanillin, 4-hydroxybenzaldehyde and piperonal were investigated. The effects of pH, temperature, time and solvent concentration on the inclusion reaction were determined. The optimum conditions were determined (pH, 3.0; temperature, normal atmospheric temperature; time, 90 min; ethanol concentration, <1%). The method was applied for the direct ultraviolet solid phase spectrophotometric determination of vanillin in peanut toffee and toffee, and the other aromatic aldehydes using β-CDP adsorbed resin with satisfactory results. The β-CDP resin has less background absorbance in ultraviolet region compared to other ion-exchanger resins.