毛细管电泳同时分离测定阿魏酸、异阿魏酸的研究

建立了同时分离测定阿魏酸、异阿魏酸的毛细管电泳(CZE)新方法。以20 mmol/L硼砂为背景电解质,体积分数15%异丙醇为有机改性剂,分离电压为20 kV,在219 nm波长下紫外检测。对硼砂浓度、有机溶剂体积分数、分离电压等因素对分离的影响做了系统的研究,最后确立了阿魏酸、异阿魏酸的最佳分离条件。阿魏酸、异阿魏酸分别在2.40~24.0μg/mL、1.80~18.0μg/mL范围内线性关系良好(r=0.9995和r=0.9991),回收率分别为96.61%~101.9%,98.80%~101.8%。方法已用于升麻中阿魏酸、异阿魏酸的测定。     

硫酸氢钠催化合成阿魏酸戊酯的研究

以正戊醇和阿魏酸为原料,一水硫酸氢钠为催化剂,直接酯化合成了阿魏酸戊酯.考察了催化剂用量、反应时间、醇酸物质的量比、带水剂用量等因素对反应的影响.确定了较佳反应条件为:阿魏酸0.2mol,n(阿魏酸)∶n(戊醇)=1∶2,一水硫酸氢钠0.5g,环己烷(带水剂)15mL,加热回流反应2h,在此反应条件下阿魏酸戊酯的产率为96.9％.     

以氢化阿魏酸为假模板制备的印迹聚合物对阿魏酸的识别

以氢化阿魏酸为假模板分子(dummy template),4-乙烯基吡啶为功能单体,通过自组装技术在乙腈中制备了对阿魏酸具有良好识别能力的印迹聚合物.采用平衡吸附法表征了聚合物在不同吸附条件下对阿魏酸的吸附特性及分子识别性能,并用紫外光谱滴定法和Scachard结合模型研究了聚合物的印迹机理和识别机理.研究表明,该聚合物对阿魏酸的识别能力甚至高于氢化阿魏酸,而且在50%的水溶液仍能有效识别阿魏酸.进一步将该聚合物用于川芎水提液中阿魏酸的提取分离,获得较好结果,显示该聚合物具有直接作为传统中药中阿魏酸分离提取材料的潜能.     

酯类前药阿魏酸丹皮酚酯的合成

以阿魏酸和丹皮酚为起始原料，先将阿魏酸的羟基用乙酰基保护得乙酰阿魏酸（1）； 1与丹皮酚经酯化反应制得乙酰阿魏酸丹皮酚酯（2）； 2在水合肼催化下水解脱去保护基合成了酯类前药阿魏酸丹皮酚酯，总收率36.0%，其结构经过¹H NMR， ¹³C NMR和MS（ESI）确证。     

以氢化阿魏酸为假模板制备的印迹聚合物对阿魏酸的识别

以氧化阿魏酸为假模板分子（dummy template），4-乙烯基吡啶为功能单体，通过自组装技术在乙腈中制备了对阿魏酸具有良好识别能力的印迹聚合物。采用平衡吸附法表征了聚合物在不同吸附条件下对阿魏酸的吸附特性及分子识别性能，并用紫外光谱滴定法和Scachard结合模型研究了聚合物的印迹机理和识别机理。研究表明，该聚合物对阿魏酸的识别能力甚至高于氧化阿魏酸，而且在50％的水溶液仍能有效识别阿魏酸。进一步将该聚合物用于川芎水提液中阿魏酸的提取分离，获得较好结果，显示该聚合物具有直接作为传统中药中阿魏酸分离提取材料的潜能。     

阿魏酸丙三酯的分子内协同抗氧化作用研究

设计并合成了一个包含3个阿魏酸抗氧化功能基团的新型抗氧化剂分子--阿魏酸丙三酯, 并以阿魏酸单体分子作对照从自由基清除效果与动力学反应活化能两个角度对比分析了阿魏酸丙三酯与DPPH^·反应间的协同抗氧化作用.     

无溶剂体系脂肪酶催化合成阿魏酸油醇酯

对无溶剂体系中阿魏酸的转酯化疏水改性进行了研究,确立了减压反应器(0.001 MPa)中Novozym 435脂肪酶催化阿魏酸乙酯和油醇进行转酯化反应合成新型抗氧化剂阿魏酸油醇酯的方法.发现水活度(aw)明显影响转酯反应,阿魏酸油醇酯产率在aw＜0.01-0.75范围内随着水活度的增加而降低,推测底物阿魏酸乙酯和产物阿...     

MSPE-HPLC测定蒲地蓝口服液中咖啡酸和阿魏酸含量

建立一种快速且高效的用于蒲地蓝口服液中的咖啡酸和阿魏酸含量测定磁固相萃取-高效液相色谱(MSPE-HPLC)法。采用磁性Mg-Al层状双金属氢氧化物(Mg-Al LDHs)作为吸附剂,利用磁固相萃取分离富集蒲地口服液中咖啡酸和阿魏酸,并利用高效液相色谱法测定咖啡酸和阿魏酸含量。结果表明咖啡酸的最大富集倍数可达24.9倍,阿魏酸最大富集倍数可达21.9倍。MSPE过程的最佳工艺为:吸附时间6min、萃取温度为35℃、样品溶液pH为7.0,解吸溶液pH为2.0、萃取剂用量为4.0 mg。在最佳室验条件下,样品的回收率分别为咖啡酸97.42%～98.57%,阿魏酸96.32%～97.84%。咖啡酸RSD为1.72%,阿魏酸RSD为2.67%。本文所建立的以磁性双金属氢氧化物为吸附剂的MSPE-HPLC法,前处理快速简便,无需特别装置,试剂用量少,对于环境污染小,可以实现蒲地蓝消炎口服液中咖啡酸和阿魏酸的同时测定。     

Luminol-H2O2-纳米银化学发光体系测定阿魏酸

碱性条件下,阿魏酸对Luminol-H2O2-纳米银化学发光体系有较强的抑制作用,基于此,结合流动注射技术,建立了测定阿魏酸的新方法。研究了影响化学发光强度的各种因素,并初步探讨了可能的发光机理。在最佳实验条件下,阿魏酸浓度在1.0×10-8～4.0×10-5mol/L范围内与相对发光强度呈线性关系,检出限(3σ)为2.0×10-9mol/L。对2.0×10-7mol/L的阿魏酸平行测定9次,相对标准偏差(RSD)为2.3%。将该法应用于太太美容口服液中阿魏酸的测定,结果满意。     

茜素红荷移光度法测定阿魏酸哌嗪

研究了茜素红与阿魏酸哌嗪的显色反应,建立了阿魏酸哌嗪含量测定的分光光度法.在水溶剂中阿魏酸哌嗪与茜素红发生荷移反应生成紫红色的复合物,其最大吸收波长为524nm,表观摩尔吸光系数为1.86×103 L·mol-1·cm-1.阿魏酸哌嗪的浓度在1.60⁴8.0mg·L-1范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.021 07+0.003 93c(mg·L-1,R=0.999 2),方法的检出限为1.19mg·L-1.将此新方法应用于阿魏酸哌嗪片中阿魏酸哌嗪含量的测定,回收率在97.5%48.0mg·L-1范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.021 07+0.003 93c(mg·L-1,R=0.999 2),方法的检出限为1.19mg·L-1.将此新方法应用于阿魏酸哌嗪片中阿魏酸哌嗪含量的测定,回收率在97.5%¹00.9%之间.     

Assay of free ferulic acid and total ferulic acid for quality assessment of Angelica sinensis

Activity of Chinese Danggui (DG), the processed root of Angelica sinensis (Oliv.) Diels, is linked to the ferulic acid content but the stability of ferulic acid during extraction for medicinal use is not known. The stabilities of ferulic acid and coniferyl ferulate were evaluated in the extracts of DG using a variety of extraction solvents. These included various combinations and proportions of methanol, water, formic acid, 1 M aqueous hydrochloric acid and 2% sodium hydrogen carbonate (NaHCO3) in water. Coniferyl ferulate was found liable to hydrolyze into ferulic acid in neutral, strongly acidic and basic solvents, where heat and water could facilitate this hydrolysis. However, the hydrolysis was relatively resisted in weakly organic acid. Based on the stability evaluation, two new terms, namely: free ferulic acid and total ferulic acid, were suggested and defined. Free ferulic acid refers to the natural content of ferulic acid in herbs. Total ferulic acid means the sum of free ferulic acid plus the amount of related hydrolyzed components. Meanwhile, the high-performance liquid chromatographic (HPLC) method was developed to assay free ferulic acid and total ferulic acid in DG using methanol-formic acid (95:5) and methanol-2% NaHCO3 in water (95:5) as extraction solvents, respectively. Ten DG samples were investigated on their contents of free and total ferulic acid. The results indicated that the amount variety of free ferulic acid was larger than that of their counterparts, and the ratio of total ferulic acid to free ferulic acid was 4.07 +/- 2.73 (mean +/- SD, n = 10). The chemical assay of DG using total ferulic acid content would be a better choice to assess the herbal quality and was recommended.     

Photostability of Ferulic Acid and Its Antioxidant Activity Against Linoleic Acid Peroxidation

Ferulic acid (4‐hydroxy‐3‐methoxycinnamic acid), a phenyl‐propenoid derivative of cinnamic acid, can undergo photolysis upon UV irradiation. The photodegradation kinetics of ferulic acid were thus investigated in different systems. The micellar solutions did not protect the acid from photodegradation. On the contrary, they catalyzed its degradation at a variable extent depending on the surfactant structure. The photodegradation of ferulic acid in microemulsions was slower than in micelles and near to that in water. TiO₂, habitually employed as a physical sunscreen, showed photocatalytic action toward ferulic acid degradation especially at higher initial concentration of ferulic acid. The action of ferulic acid on the peroxidation of linoleic acid in micelles and microemulsions also was evaluated. When the ferulic acid is absent the peroxidation is continuous while when it is present an induction time of 40 minutes or higher was observed. Accordingly, it is likely that linoleic acid acts as photosensitizer for ferulic acid, and that in turn ferulic acid acts as an antioxidant for linoleic acid, reducing the rate of peroxidation.     

Chemiluminescence determination of ferulic acid by flow-injection analysis using cerium(IV) sensitized by rhodamine 6G

A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with rhodamine 6G and ceric sulfate in sulphuric acid medium. Strong chemiluminescence signal was observed when ferulic acid was injected into the acidic ceric sulfate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 8.0x10(-6) to 1.0x10(-4)moll(-1) and the detection limit for ferulic acid was 8.7x10(-9)moll(-1). The relative standard deviation was 2.4% for 10 replicate analyses of 1.0x10(-5)moll(-1) ferulic acid. The proposed method was applied to the determination of ferulic acid in Taita Beauty Essence samples with satisfactory results.     

Permanganate-based chemiluminescence analysis of ferulic acid using flow injection.

A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with potassium permanganate in a nitric acid medium. A strong chemiluminescence signal was observed when ferulic acid was injected into an acidic potassium permanganate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 6.0 x 10(-6) to 2.0 x 10(-4) mol l(-1); the detection limit (3sigma) for ferulic acid was 9.6 x 10(-8) mol l(-1). The relative standard deviation was 1.0% for 11 replicate analyses of 2.0 x 10(-4) mol l(-1) ferulic acid. The proposed method was applied to the determination of ferulic acid in real samples with satisfactory results. Moreover, the reaction mechanism of the chemiluminescence system was primarily considered.     

KMnO4-乙二醛化学发光体系测定阿魏酸

酸性介质下,KMnO4氧化阿魏酸产生化学发光,乙二醛对该体系有增敏作用。结合流动注射技术,建立了测定阿魏酸的流动注射化学发光新方法。该方法线性范围为1.0×10-7～2.0×10-5mol/L,检出限为1.0×10-8mol/L,对1.0×10-6mol/L的阿魏酸平行测定11次,相对标准偏差为2.8%。该法用于太太美容口服液中阿魏酸的测定,结果令人满意。     

Corn Fiber: Structure, Composition, and Response to Enzymes for Fermentable Sugars and Coproducts

Corn (Zea mays L.) fiber, which is the seed coat and residual endosperm left after grain processing, is a low-value residue that contains carbohydrates and aromatic compounds that could provide value-added coproducts. Treatment of corn fiber with NaOH and assessment by gas chromatography indicated a prevalence of ferulic acid, with about 90% ester-linked in the cell walls. p-Coumaric acid was much lower at about 10% of the amount of ferulic acid. Histochemical reactions employing acid phloroglucinol and diazotized sulfanilic acid indicated the presence of phenolic acids in cell walls of the pericarp and aleurone layer. Various protocols were tested using milled corn fiber and pretreatment with commercial ferulic acid esterases before cellulase treatment, and dry weight loss and sugars and phenolic acids released into the filtrate were evaluated. Ferulic acid esterases effectively degraded corn fiber and released substantial amounts of ferulic acid and sugars (e.g., glucose and xylose) in the incubation medium. Light microscopy showed that ferulic acid esterase substantially disrupted the aleurone layer but caused little visible damage to the lignified pericarp cell walls. Amounts of compounds released varied with protocols, and one study with various milling methods showed that esterase pretreatment followed by cellulase released about 2.8 to 4.4 and 1.5 to 2.9 times more ferulic acid and glucose, respectively, than cellulase alone. The highest levels for one lot of corn fiber with esterase pretreatment followed by cellulase were 3.9 and 218 mg/g of ferulic acid and glucose, respectively.     

阿魏酸分子结构和振动光谱的理论研究

阿魏酸是一种有效的天然油脂抗氧化剂.采用密度泛函理论(DFT) B3LYP方法和从头算HF两种方法,在6-311++G**基组水平上对阿魏酸分子的几何结构进行全优化,得到其几何结构参数,进一步计算得到阿魏酸的红外和拉曼振动光谱.计算结果表明,采用B3LYP和HF 2种方法优化得到的几何结构及频率值是一致的,对在B3LYP方法下计算得到的红外和拉曼振动频率进行合理的理论归属并与SDBS数据库实验数据进行比较,发现计算得到的红外和拉曼振动频率与实验测定结果符合较好.阿魏酸分子结构和振动光谱的研究,为研究阿魏酸及其衍生物的化学结构与生理活性之间的构效关系提供依据.     

Extraction of ferulic acid from Angelica sinensis with supercritical CO2

Extraction of pharmacologically active ingredient of ferulic acid from the root of Angelica sinensis with supercritical CO2 was investigated. The experimental results show that the extract yields were 0.87-4.06% at temperatures from 45 to 65 degrees Celsius and pressures from 30 to 50 MPa, and the maximum content of ferulic aicd in the extracts was about 0.35-0.37%, which is lower than that of 0.61-0.85% by conventional percolation methods. Ethanol was used as co-solvent in different ratios to raw materials in order to increase the content of ferulic acid in the extracts. The experimental results show that both the extract yields and the content of ferulic acid in the extracts increase greatly compared with pure CO2 extraction. When the ratio of ethanol to the raw material was 1.6, the content of ferulic acid in the extracts was 0.91-1.27%, indicating that supercritical fluid extraction (SFE) with CO2 in the presence of suitable co-solvent is superior to percolation in extracting polar ferulic acid from Angelica sinensis.     

Determination of ferulic acid and adenosine in Angelicae Radix by micellar electrokinetic chromatography

A micellar electrokinetic chromatography for determining ferulic acid and adenosine in Angelicae Radix was developed. A buffer solution composed of 50 mmol L(-1) borax, 10 mmol L(-1) sodium deoxycholate, and 2% methanol was found to be the most suitable electrolyte for the separation. The contents of ferulic acid and adenosine in Angelicae Radix were determined within 20 min. Good linearity between peak area ratio and the concentration was found in the range of approximately 20-320 microg mL(-1) for ferulic acid and about 10-160 microg mL(-1) for adenosine ( r >0.998), respectively. The recoveries were approximately 96.8-97.4% and 93.2-95.0%, and the RSD of this proposed method were 4.4% and 3.2% for ferulic acid and adenosine, respectively ( n=5). The contents of ferulic acid and adenosine in Angelicae Radix from different sources were determined.     

Interactions between bioactive ferulic acid and fumed silica by UV–vis spectroscopy, FT-IR, TPD MS investigation and quantum chemical methods

The interactions of bioactive ferulic acid with fumed silica were studied by UV/vis spectroscopy, FT-IR, TPD MS techniques and quantum chemical methods. It was found that surface complexes may form through phenol or carboxyl group of ferulic acid depending on its coverage value. The structure of surface complexes and mechanisms of the ferulic acid chemosorption on the silica surface are discussed. The kinetic parameters of the chemical reactions on silica surface are calculated. The mechanisms of thermal transformations of the ferulic chemosorbed surface complexes are proposed.