黄烷醇类化合物抗氧化性的构效关系研究

本文采用分子力学和量子化学从头计算方法，系统地计算了阿福豆素、儿茶素和培儿茶素等三种黄烷醇类化合物的能量与电子结构，讨论了黄烷醇类化合物各种立体异构体的结构稳定性和酚羟基反应活性问题。另外计算了黄烷醇类化合物在脱氢氧化反应过程中生成自由基和类醌化合物的能量变化和电子结构的变化，根据计算结果阐明了黄烷醇类化合物抗氧化性顺序，并从能量和电子结构的角度给予了理论解释。     

黄烷-3-醇类化合物在体内的吸收、代谢特征与机制研究进展

黄烷-3-醇类化合物是人类饮食中含量最丰富的膳食多酚之一,近年来,黄烷-3-醇类化合物备受关注,这主要是因为许多研究发现其与很多慢性疾病风险的降低和代谢综合征的缓解密切相关,但黄烷-3-醇类化合物在体内发挥的作用一定程度上取决于其被摄入后的吸收和代谢,尤其是肠道微生物的分解代谢。因此,本文将重点探讨黄烷-3-醇类化合物的吸收、代谢及其生物转化的途径,有助于揭示其在体内的生物学作用。     

苹果酒酚类物质研究进展

苹果酒中含有多种酚类物质,主要是酚酸类和类黄酮类化合物,酚酸类包括绿原酸、原儿茶酸和p-香豆酸等,类黄酮类主要是黄烷-3-醇类,包括儿茶素、表儿茶素等.这些成分对苹果酒的风味、颜色和质量起着重要作用.综述了苹果酒中的酚类化合物及其作用机理,并简要介绍了酚类物质的测定方法.     

天然化合物基于Notch通路抑制肿瘤的研究进展

恶性肿瘤是威胁人类健康的全球疾病负担,我国恶性肿瘤新发病例和新发癌症死亡病例均位居全球首位,因此抗肿瘤药物的开发备受关注。Notch信号通路广泛存在于人体各种器官,是影响肿瘤发生与发展的关键信号传导途径之一,关系到肿瘤细胞的多种受体与细胞功能。该信号通路机制复杂,出现异常的激活或阻断将会导致机体紊乱,引起恶性肿瘤的发生。我国植物种类丰富多样,其中不乏食品药品资源,来源植物的天然化合物由于其对于癌症治疗具有积极影响,更是成为近年来抗肿瘤研究及药物开发的热点。已有大量研究表明,天然化合物能够通过靶向Notch通路对多种肿瘤发挥抑制作用。本文就Notch通路与肿瘤的关系、天然化合物基于Notch信号对抗肿瘤的作用机制研究现状进行归纳综述,并对其未来的研究方向进行了展望。旨在为靶向Notch的抗肿瘤药物开发以及植物资源的利用提供理论参考与科学思路。     

陈年生普与熟普的黄烷醇类活性成分分析

采用Folin-Ciocalteu比色法和LC-DAD-ESI-MS法对陈年生普(以下简称APT)和熟普(以下简称YPT)中总多酚(The total phenolic,TPC)和黄烷醇类活性成分进行分析。研究结果表明,从APT和YPT中确定了8种黄烷醇类活性成分,它们分别是儿茶素(C)、表儿茶素(EC)、表儿茶素没食子酸酯(ECG)、表没食子儿茶素(EGC)、表没食子儿茶素没食子酸酯(EGCG)、没食子儿茶素(GC)、没食子儿茶素没食子酸酯(GCG)、儿茶素没食子酸酯(CG)。2种茶中GC含量差异不显著,APT中的TPC和其余7种黄烷醇类化合物含量均显著高于YPT中。不同产地普洱茶的TPC和8种黄烷醇类化合物含量差异不显著,不同年份差异显著。主成分分析法(PCA)和层次聚类分析(HCA)依据TPC和黄烷醇类化合物能将APT和YPT很好的聚类,成功区分出APT和YPT样品;除GC外的其余7种黄烷醇类化合物和TPC均是很好的化学标记。     

芬芳的礼物

生物类黄酮是广泛分布于植物中的一大类衍生化合物,目前已知的类黄酮化合物已有一千多种.它们包括黄酮、黄酮醇、异黄酮、黄烷酮、查耳酮、花色素、色原酮等,其中食品中的主要类黄酮有黄烷酮、黄酮、黄酮醇和异黄酮四类.生物类黄酮具有生物活性和生理作用,特别是其抗氧化、抗自由基及抗癌、防癌的作用.因此,如何有效地提取和分离提纯生物类黄酮对其开发应用越来越关键.     

黄酮类化合物的保健作用

黄酮类化合物(Flavonoids),又称生物类黄酮(Bioflavonoids),早期是指具有乙一苯基吡喃酮结构的一类黄色素,现指具有色酮环与苯环为基本结构的一类化合物的总称。可以分类为:黄酮类、黄酮醇类、异黄酮类、黄烷酮类等,广义的范围还包括查耳酮、嗅酮、异黄烷酮、双黄酮(Biflavonoids)及茶多酚(儿茶素的结构、性质及作用与类黄酮相似,也可归于黄酮类化合物中),其中黄酮醇是重要的一类。一、黄酮类化合物的摄入量及在食物中的含量(一)类黄酮在部分食物中的含量果蔬中黄酮类化合物几乎以配糖体形式存在,且含量较低,如洋葱、土豆、包心菜、芹菜、…     

高车前素抗肿瘤机制的研究进展

高车前素是一种天然黄酮类化合物,生物活性广泛,抗肿瘤活性显著。大量体内外研究表明,高车前素可通过促进肿瘤细胞凋亡,抑制肿瘤细胞增殖、转移和侵袭及肿瘤血管生成等作用对多种恶性肿瘤发挥抗肿瘤功效。本文对高车前素的抗肿瘤作用机制进行综述,为高车前素药物的开发和应用提供参考。     

葡萄浆果中的主要多酚化合物及影响因素

本文综述了葡萄浆果中的酚酸类、黄酮醇类、黄烷醇娄、黄烷酮醇娄、花色苷娄等主要多酚化合物。葡萄中阶类物质的种类和含量随内在因素如不同种、品种以及果实的不同部位而有差异。同时外界因素如光照、温度和栽培措施等也对其产生明显影响。     

大豆制品中腥味形成机理及去腥工艺研究进展

大豆制品含有丰富的优质蛋白、不饱和脂肪酸、钙和B族维生素,经常食用可以增进和保护人体健康。但是大豆中天然存在的豆腥味降低了消费者的接受度,同时也限制了豆制品进一步的开发。该研究结合国内外豆制品的最新研究现状,对醛类、醇类、酮类、酮类等豆腥味相关物质及豆腥味化合物在酶促反应和非酶促反应等形成途径和机理进行了系统阐述。随后从物理、化学、生物等四个方面对已有的大豆去腥工艺进行概括,并比较分析去腥工艺的优缺点,为开发无豆腥味豆制品,推动大豆类产品消费提供理论参考。     

天然植物中原花青素提取和纯化方法研究进展

原花青素属于多酚类化合物,与植物多糖、生物黄酮等活性物质一样广泛存在于各种植物之中。近年来针对植物中原花青素活性功能研究逐渐增多,研究发现其具有很强的生物活性,如清除自由基、抗癌、抗突变、预防和治疗心血管疾病等,且安全无毒。现在原花青素已广泛应用于临床医学、化妆品、保健食品和食品工业等领域。目前天然植物中原花青素的提取和纯化研究已经成为热门课题,本文主要总结归纳了原花青素溶剂浸提法、超声辅助提取法、微波辅助提取法、离子液体提取法、超临界流体提取法、酶提取法6种提取工艺和大孔树脂吸附法、高速逆流色谱法、膜过滤法、凝胶色谱法4种纯化方法,简要介绍了其基本原理,同时分析了各方法的优缺点,以期为以后的相关科研工作提供一定的参考。     

Preservation of Cocoa Antioxidant Activity, Total Polyphenols, Flavan-3-ols, and Procyanidin Content in Foods Prepared with Cocoa Powder

ABSTRACT:  Little is known about the effects of common cooking processes on cocoa flavanols. Antioxidant activity, total polyphenols (TP), flavanol monomers, and procyanidin oligomers were determined in chocolate frosting, a hot cocoa drink, chocolate cookies, and chocolate cake made with natural cocoa powder. Recoveries of antioxidant activity, TP, flavanol monomers, and procyanidins ranged from 86% to over 100% in the chocolate frosting, hot cocoa drink, and chocolate cookies. Losses were greatest in the chocolate cake with recoveries ranging from 5% for epicatechin to 54% for antioxidant activity. The causes of losses in baked chocolate cakes were investigated by exchanging baking soda with baking powder or combinations of the 2 leavening agents. Use of baking soda as a leavening agent was associated with increased pH and darkening color of cakes. Losses of antioxidant activity, TP, flavanol monomers, and procyanidins were associated with an increased extractable pH of the baked cakes. Chocolate cakes made with baking powder for leavening resulted in an average extractable pH of 6.2 with essentially complete retention of antioxidant activity and flavanol content, but with reduced cake heights and lighter cake color. Commercially available chocolate cake mixes had final pHs above 8.3 and contained no detectable monomeric flavanols after baking. These results suggest that baking soda causes an increase in pH and subsequent destruction of flavanol compounds and antioxidant activity. Use of an appropriate leavening agent to moderate the final cake pH to approximately 7.25 or less results in both good leavening and preservation of cocoa flavanols and procyanidins.     

绿茶中多酚物质的抗氧化活性及其在肉制品中的应用研究进展

绿茶自古以来就是人类的重要饮料,在亚洲很多国家广泛饮用并被认为对人体健康具有益处。绿茶酚类化合物作为天然抗氧化剂在食品工业中尤其在肉制品中应用十分广泛且意义重大,加入绿茶提取物产品的抗氧化能力得到有效增强,并且减少了加工和储存保藏期间因氧化反应造成的不良变化,从而延长了保质期。本文首先综述了绿茶中酚类化合物的组成,其次简述了酚类化合物发挥抗氧化活性的抗氧化机制以及其产生的生物活性对人体健康的潜在益处,最后阐述了酚类化合物在肉制品中起到抗氧化、抑菌、护色等作用,并对今后的发展趋势进行了展望。     

植物中白藜芦醇提取和检测方法研究进展

白藜芦醇是一种天然非黄酮类多酚化合物,主要存在于虎杖、花生、葡萄等植物中。因为白藜芦醇具有抗癌、抑菌、保护肝脏等生理功能。所以成为近年来医学和食品行业共同关注的焦点。本文在对植物中白藜芦醇相关文献统计分析的基础上,综述了植物中白藜芦醇的结构与理化性质,重点介绍了白藜芦醇的提取、纯化、检测等最新方法的研究进展,以期为将来植物中白藜芦醇的高值化利用提供依据。     

Mass spectrometry fragmentation pattern of coloured flavanol‐anthocyanin and anthocyanin‐flavanol derivatives in aged red wines of Rioja

Background and Aims: During wine ageing, a great variety of reactions take place, resulting in an immense variety of products whose structure sometimes remains unknown. The aim of this work is the study of different fragmentation patterns of flavanol‐anthocyanin derivatives formed along the wine ageing; these patterns are useful for elucidating the different structures of these compounds and other new related ones. Methods and Results: Several wines from the Protected Denomination of Origin Rioja have been studied by an analytical method that combines column chromatography and high‐performance liquid chromatography with diode array and mass and tandem mass spectrometric detections. Thirty‐five coloured flavanol‐anthocyanin compounds formed by direct reaction or by acetaldehyde‐mediated condensation have been identified. For direct reaction derivatives, two different fragmentation patterns (one of them not previously reported) have been observed depending on the position of flavanol in the coloured derivative. Several compounds have been identified in aged wines for the first time to the authors' knowledge, like (+)‐gallocatechin‐cyanidin‐3‐glucoside and (+)‐catechin‐cyanidin‐3‐glucoside Conclusions: The developed analytical procedure has allowed the identification of some compounds for the first time, and two different fragmentation patterns have been observed depending on the position of flavanol in the pigment. Significance of the Study: The establishment of different fragmentation patterns allows the structural elucidation of unknown compounds.     

微生物法生产虾青素的研究进展

虾青素是一种萜烯类不饱和化合物,具有很强的抗氧化活性,同时还具有抗癌、增强免疫、护眼、保护心脑血管等其他诸多生理功能。天然虾青素主要来源于藻类、酵母以及海洋生物中。目前应用于市场的虾青素主要包括雨生红球藻虾青素、酵母虾青素以及化学合成虾青素。雨生红球藻的培养时间长,生长条件要求苛刻,使得虾青素价格昂贵;化学合成虾青素为混合构型虾青素,抗氧化能力低于天然虾青素,安全性较差。该文介绍了虾青素的结构性质、虾青素来源和生产方法,着重讲述红法夫酵母（Phaffia rhodozyma）生产虾青素的生物合成途径、发酵培养条件以及虾青素的破壁提取和纯化方法,为虾青素工业化生产提供一定理论基础。     

蔬菜纸型化制浆技术

以保护蔬菜原有天然营养成分,保持蔬菜膳食纤维形态为基础,试验分析适宜蔬菜纸型化生产的制浆设备、匀质成浆、产业化等因素,改进完善蔬菜纸型化制浆技术,为今后蔬菜纸型化生产的标准参数提供参考。     

天然多糖的硫酸化修饰对其生物活性影响研究进展

多糖是广泛存在于生物体内的一类生物活性大分子,因其具有多种生物活性,已引起国内外学者的高度关注。近年来研究发现,通过硫酸化修饰,可以改善多糖的生物活性,使其具有其他天然多糖无法比拟的生物活性。本文对多糖的硫酸化修饰方法及其生物活性进行综述,为今后开展硫酸化多糖的深入研究及开发应用提供参考。     

Oak barrel maturation vs. micro-oxygenation: Effect on the formation of anthocyanin-derived pigments and wine colour

The objective of this study was to check whether micro-oxygenation (MO) could mimic oak barrel ageing as regard the effect on wine colour. A red wine was submitted to micro-oxygenation for three months while another lot from the same wine was matured in oak barrels for three or six months. After these times, oak-matured and micro-oxygenated wines were bottled and analyzed six months later. The chromatic characteristics of these wines were also compared with those of a control wine that remained in a stainless steel tank all the time. Anthocyanins and anthocyanin-derived compounds were studied by LC–ESI-MS. Monomeric anthocyanins and other compounds including direct anthocyanin–flavanol adducts, ethyl-linked anthocyanin–flavanol compounds, and pyranoanthocyanins were detected. The application of MO for three months produced wines with a lower concentration of monomeric anthocyanins and a higher concentration of vitisin-related pigments than the control wine, the oak mature wines showing similar results than MO wines when aged for the same period of time. Differences were also observed in the chromatic characteristics, the micro-oxygenated and the oak matured wines showing a higher colour intensity than control wine. However, after six months in bottle differences were found between the micro-oxygenated wines and oak matured wines, the latter showing a more stable colour, probably due to the beneficial effects of compounds extracted from the wood (e.g. ellagitannins or wood aldehydes).