结构预测及分子对接方法研究几种水解产物对新阿魏酸酯酶的抑制作用

应用基于生物信息学的蛋白质结构预测方法, 探讨了来源于荷斯坦奶牛瘤胃宏基因组文库的一个新型阿魏酸酯酶(FAE-SH1)的结构及可能的催化机制. 同时通过对该酶的预测结构与4种模式底物的对接研究发现, 实验所测得酶促反应动力参数V_max与对接的亲和能存在线性关系, 底物与酶形成的氢键可能是影响催化效率的关键因素. 同时, 本研究发现D-木糖、 L-阿拉伯糖、 D-葡萄糖及阿魏酸能够对FAE-SH1的水解反应产生抑制作用, 并对其进行了验证.     

Maniplating the phenolic acid content and digestibility of italian ryegrass (Lolium multiflorum)b y vacuolar-targeted epession of a fungal ferulic acid esterase

In grass cell walls, ferulic acid esters linked to arabinosyl residues in arabinoxylans play a key role in crosslinking hemicellulose. Although such crosslinks have a number of important roles in the cell wall, they also hinder the rate and extent of cell wall degradation by ruminant microbes and by fungal glycohydrolyase enzymes. Ferulic acid esterase (FAE) can release both monomeric and dimeric ferulic acids from arabinoxylans making the cell wall more susceptible to further enzymatic attack. Transgenic plants of Lolium multiflorum expressing a ferulic acid esterase gene from Aspergillus niger, targeted to the vacuole under a constitutive rice actin promoter, have been produced following microprojectile bombardment of embryogenic cell cultures. The level of FAE activity was found to vary with leaf age and was highest in young leaves. FAE expression resulted in the release of monomeric and dimeric ferulic acids from cell walls on cell death and this was enhanced severalfold by the addition of exogenous β-1,4-endoxylanase. We also show that a number of plants expressing FAE had reduced levels of cell wall esterified monomeric and dimeric ferulates and increased in vitro dry-matter digestibility compared with nontransformed plants.     

具酯酶活性的温敏型分子印迹微凝胶

以双醛葡聚糖-组氨酸偶连物(PAD-His)为功能大单体、过渡态类似物p-硝基苯磷酸酯(NPP)为模板分子、Co2+为中心离子,采用油包水反相乳液法首次制得具有酯酶活性的温敏型分子印迹微凝胶(MIGs).催化水解实验表明,MIGs催化活性受模板分子用量的影响,并可通过温度进行有效调控.MIGs催化p-硝基乙酸苯酯(NPA)水解反应行为可用Michaelis-Menten方程进行描述,其最大催化水解反应速率和Michaelis-Menten常数分别为2.04×10-8mol/h和2.2×10-5mol/L,且具有较好的催化选择性.     

Temperature-sensitive molecularly imprinted microgels with esterase activity

Temperature-sensitive molecularly imprinted microgels(MIGs)exhibiting esterase activity were prepared by a reverse emulsion method using dialdehyde dextran-histidine conjugate(PAD-His)as the functional macromonomer and p-nitrophenyl phosphate(NPP)as the stable transition state analogue(TSA)as well as Co2+as the coordination center.The catalytic activity of MIGs was greatly influenced by the amount of the template,and could be modulated by temperature.The hydrolysis kinetics of p-nitrophenyl acetate(NPA)in t...     

Selection of cholesterol esterase aptamers using a dual‐partitioning approach

Non‐systematic evolution of ligands by exponential enrichment and other capillary‐based methods have grown in popularity for selection of aptamers since they provide a fast and efficient partitioning method when compared to classical techniques. Despite promising developments in these techniques, a major obstacle needs to be overcome for capillary‐based selections to be widely accepted. Due to the small injection volumes associated with CE, only a small proportion of the nucleic acid library can be partitioned at any one time. In this paper, we propose a new two‐step method for the selection of aptamers which firstly incorporates a nitrocellulose membrane filter followed by CE. This technique allows for nonbinding sequences to be eliminated, reducing the library size before subsequent capillary‐based partitioning, while still reducing the time taken for aptamers to be selected. We demonstrated this technique on the selection of aptamers for cholesterol esterase and the highest binding truncated aptamer CES 4T displayed a K_D of 203 ± 14 nM. In addition, an increase in the number of sequences partitioned was estimated using spectrophotometry and capillary injection volumes. The results suggested that for successful selection a two‐step approach is needed. This hybrid technique could be used to select aptamers that bind to targets both in solution and immobilized onto a stationary phase, allowing the aptamers to be used in different binding environments.     

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。     

FRET-based fluorescence probes for hydrolysis study and pig liver esterase activity

New fluorescent probes based on simple organic synthesis were designed and synthesized, and their hydrolysis catalyzed via base and pig liver esterase (PLE) was studied using FRET (fluorescence resonant energy transfer), with 1-naphthylacetic group as a donor and dansyl group as an acceptor. By simultaneous recording of changes of the donor fluorescence intensities, kinetic parameters for base-catalyzed and PLE-catalyzed hydrolysis can be determined. The presented FRET assay is a convenient and simple method and both fluorescent probes are good real-time indicators for the analysis of ester hydrolysis such as PLE activities.     

Anticholine esterase activity of phosphonium bis-zwitterions based on 2-cyanoacrylates

Phosphonium bis-zwitterions based on bis-2-cyanoacrylates are weak reversible inhibitors of choline esterases with a diverse anticholine esterase effect. This can find use in additional classification of choline esterases. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2192–2194, November, 1999.     

Amperometric cholesterol biosensor based on immobilized cholesterol esterase and cholesterol oxidase on conducting polypyrrole films

Fabrication of an amperometric cholesterol biosensor by co-immobilization of cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) onto conducting polypyrrole (PPY) films using electrochemical entrapment technique is described. Electrochemical polymerization was carried out using a two-electrode cell configuration at 0.8 V. Characterization of resulting amperometric biosensor for the estimation of cholesterol has been experimentally determined in terms of linear response range, optimum pH, applied potential, temperature, and shelf-life. These PPY/ChEt/ChOx electrodes can be used for cholesterol ester estimation from 1 to 8 mM and have shelf-life of about 4 weeks at 4 °C during which about 15 estimations of cholesterol ester could be made. The sensitivity of PPY/ChEt/ChOx electrode has been found to be 0.15 μA/mM and the apparent K_m value for this electrode is 9.8 mM. Conductivity of the polymer films found to be about 3×10⁻³ S/cm.     

Pharmacological Insights into Halophyte Bioactive Extract Action on Anti-Inflammatory,Pain Relief and Antibiotics-Type Mechanisms

The pharmacological activities in bioactive plant extracts play an increasing role in sustainable resources for valorization and biomedical applications. Bioactive phytochemicals, including natural compounds, secondary metabolites and their derivatives, have attracted significant attention for use in both medicinal products and cosmetic products. Our review highlights the pharmacological mode-of-action and current biomedical applications of key bioactive compounds applied as anti-inflammatory, bactericidal with antibiotics effects, and pain relief purposes in controlled clinical studies or preclinical studies. In this systematic review, the availability of bioactive compounds from several salt-tolerant plant species, mainly focusing on the three promising species Aster tripolium, Crithmum maritimum and Salicornia europaea, are summarized and discussed. All three of them have been widely used in natural folk medicines and are now in the focus for future nutraceutical and pharmacological applications.     

阿魏酸的合成和应用

介绍了阿魏酸的结构、性质、合成方法,其中生物合成法具有广阔的开发和应用前景。阿魏酸因其独特而优良的药理活性在食品、保键品、化妆品、医药等方面有着广泛的用途。     

Complexation of Caffeic and Ferulic Acids by Transition-Metal Ions

Potentiometric titration and IR and UV spectroscopies are used to study complexation of caffeic and ferulic acids by metal ions. Caffeic and ferulic acids, which occur in lignin, are shown to react with metal ions mainly through an ionic mechanism. However, coordination bonding is also possible depending on the nature of the ligand and metal ion and the ratio of starting components. The strongest complex forms between caffeic acid and CuCl ₂ (2:1 ratio)     

Facile Amidation of Non-Protected Hydroxycinnamic Acids for the Synthesis of Natural Phenol Amides

Phenol amides are bioactive compounds naturally present in many plants. This class of compounds is known for antioxidant, anti-inflammatory, and anticancer activities. To better understand the reactivity and structure–bioactivity relationships of phenol amides, a large set of structurally diverse pure compounds are needed, however purification from plants is inefficient and laborious. Existing syntheses require multiple steps, including protection of functional groups and are generally overly complicated and only suitable for specific combinations of hydroxycinnamic acid and amine. Thus, to facilitate further studies on these promising compounds, we aimed to develop a facile general synthetic route to obtain phenol amides with a wide structural diversity. The result is a protocol for straightforward one-pot synthesis of phenol amides at room temperature within 25 h using equimolar amounts of N,N′-dicyclohexylcarbodiimide (DCC), amine, hydroxycinnamic acid, and sodium bicarbonate in aqueous acetone. Eight structurally diverse phenol amides were synthesized and fully chemically characterized. The facile synthetic route described in this work is suitable for a wide variety of biologically relevant phenol amides, consisting of different hydroxycinnamic acid subunits (coumaric acid, ferulic acid, and sinapic acid) and amine subunits (agmatine, anthranilic acid, putrescine, serotonin, tyramine, and tryptamine) with yields ranging between 14% and 24%.     

Immobilization of cholesterol esterase and cholesterol oxidase onto sol-gel films for application to cholesterol biosensor

Cholesterol oxidase (ChOx) and cholesterol esterase (ChEt) have been covalently immobilized onto tetraethylorthosilicate (TEOS) sol-gel films. The tetraethylorthosilicate sol-gel/ChEt/ChOx enzyme films thus prepared have been characterized using scanning electron microscopic (SEM), UV-vis spectroscopic, Fourier-transform-infrared (FTIR) spectroscopic and amperometric techniques, respectively. The results of photometric measurements carried out on tetraethylorthosilicate sol-gel/ChEt/ChOx reveal thermal stability up to 55 °C, response time as 180 s, linearity up to 780 mg dL⁻¹ (12 mM), shelf life of 1 month, detection limit of 12 mg dL⁻¹ and sensitivity as 5.4 × 10⁻⁵ Abs. mg⁻¹ dL⁻¹.     

Use of Ferulic Acid in the Management of Diabetes Mellitus and Its Complications

Diabetes mellitus, a metabolic disease mainly characterized by hyperglycemia, is becoming a serious social health problem worldwide with growing prevalence. Many natural compounds have been found to be effective in the prevention and treatment of diabetes, with negligible toxic effects. Ferulic acid (FA), a phenolic compound commonly found in medicinal herbs and the daily diet, was proved to have several pharmacological effects such as antihyperglycemic, antihyperlipidemic and antioxidant actions, which are beneficial to the management of diabetes and its complications. Data from PubMed, EM-BASE, Web of Science and CNKI were searched with the keywords ferulic acid and diabetes mellitus. Finally, 28 articles were identified after literature screening, and the research progress of FA for the management of DM and its complications was summarized in the review, in order to provide references for further research and medical applications of FA.     

HPLC法测定浓缩当归丸中阿魏酸的含量

建立了浓缩当归丸中阿魏酸的HPLC测定方法.采用C18色谱柱(TSK-GEL,4.6×150 mm,5μm),以甲醇-水-磷酸(30∶70∶0.3,V/V/V)为流动相,流速1.0 mL/min,检测波长320 nm.结果阿魏酸在0.006~0.15μg范围内线性关系良好,r为0.9999,平均加样回收率为96.91%.本方法可用于浓缩当归丸中阿魏酸的含量监控.     

Ferulic Acid: A Natural Phenol That Inhibits Neoplastic Events through Modulation of Oncogenic Signaling

Despite the immense therapeutic advances in the field of health sciences, cancer is still to be found among the global leading causes of morbidity and mortality. Ethnomedicinally, natural bioactive compounds isolated from various plant sources have been used for the treatment of several cancer types and have gained notable attention. Ferulic acid, a natural compound derived from various seeds, nuts, leaves, and fruits, exhibits a variety of pharmacological effects in cancer, including its proapoptotic, cell-cycle-arresting, anti-metastatic, and anti-inflammatory activities. This review study presents a thorough overview of the molecular targets and cellular signaling pathways modulated by ferulic acid in diverse malignancies, showing high potential for this phenolic acid to be developed as a candidate agent for novel anticancer therapeutics. In addition, current investigations to develop promising synergistic formulations are also discussed.     

米糠中阿魏酸的提取及荧光分光光度法检测

确定了新鲜米糠中阿魏酸的最佳提取工艺。用高效液相色谱法对提取产品作定性检测,用荧光分光光度法对提取产品作定量检测。阿魏酸在0.2~2.2μg/mL浓度范围内呈良好的线性关系,相关系数为0.99958,平均回收率为99.0%。此法具有准确、简便、快速、灵敏等优点。     

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。