原花青素分离鉴定方法的研究进展

随着原花青素生理、药理活性被初步揭示,原花青素分离鉴定的研究正成为一个新的研究重点.主要就纸色谱法、薄层色谱法、HPLC分析鉴定、毛细管电泳分离鉴定等方法对原花青素进行分离鉴定的研究近况予以综述.     

酒花原花青素抗氧化性能研究

将酒花中原花青素提纯并进行聚合度分级,获得不同平均聚合度(DP)的七种原花青素.对七种原花青素聚合物在水相和油相中的抗氧化性能进行研究.与(+)-儿茶素和抗坏血酸相比较,(DP)为1.5～4.0的原花青素还原能力较(+)-儿茶素和抗坏血酸强,而(DP)为5.55的原花青素还原能力最弱.不同聚合度的酒花原花青素对脂质体的氧化过程的抑制作用具有一定的浓度效应,在高浓度时,(DP)为2.97和3.50的原花青素在人工脂质体体系中的抗氧化效果较好.同时,研究发现低聚合度的原花青素在亚油酸体系中具有较好的抗氧化作用.     

原花青素分级分离

原花青素由(+)-儿茶素、(-)-表儿茶素、(-)-表儿茶素没食子酸酯聚合而成,聚合度、单体及连接键的不同使得原花青素具有多种异构体,造成分离分析困难.原花青素的抗氧化活性受聚合度影响,按聚合度大小对原花青素分级分离,对产品性能进行评价.用10％～ 40％和60％乙醇溶液对吸附在AB-8大孔树脂上的原花青素梯度洗脱,原花青素洗脱收率达到98.63％.分析各乙醇洗脱液中原花青素平均聚合度和抗氧化活性,0％ ～ 12％乙醇洗脱液中为单体,12％ ～32％洗脱液中主要为低聚体,32％～60％洗脱液中为高聚体,12％ ～ 32％洗脱液原花青素抗氧化活性最高,自由基清除率为44.85％,维生素C当量浓度为19.38 μg/mL.     

葡萄籽原花青素的聚合度与抗氧化活性关系

采用亚油酸体系和脂质体体系研究葡萄籽原花青素不同聚合度组分的抗氧化活性。结果表明,葡萄籽原花青素具有很强的抗氧化能力,在亚油酸及脂质体体系中,原花青素的抗氧化活性高于VC和VE,并且随着浓度的增加其抗氧化能力与合成抗氧化剂BHT相近。聚合度对原花青素抗氧化作用的影响较大,单体对脂质体体系的抗氧化活性低于二聚体,对于聚合体而言,原花青素对亚油酸体系和脂质体体系的抗氧化作用均随着聚合度的升高而降低。     

地榆原花青素聚合度对抗氧化活性影响的研究

采用醋酸水解法在不同条件下制备不同平均聚合度的地榆原花青素.通过DPPH法、羟基自由基法以及核黄素光化学氧化-偶氮显色分光光度法测定地榆原花青素抗氧化、清除自由基能力,实验表明聚合度和清除DPPH自由基无关,而对HO·,O_2~-·清除能力随聚合度降低而增强.原花青素的自由基捕捉能力随着聚合度的降低而增强.     

高压微射流处理对原花青素平均聚合度和抗氧化性能的影响

为提高原花青素的生物利用度,本研究采用高压微射流技术处理原花青素溶液,探究其对原花青素平均 聚合度及其抗氧化能力的影响。将原花青素在不同处理压力（100、140、180、220 MPa和260 MPa）下分别进行 1、2、3、4 次循环处理,结果表明：随着处理压力的升高,原花青素的平均聚合度基本不存在显著差异,220 MPa 下平均聚合度相对较低;处理次数为4条件下的平均聚合度相对较小。固定处理次数为4,选择不同处理压力的样 品进行抗氧化能力分析,抗氧化能力（包括铁还原力和清除1,1-二苯基-2-三硝基苯肼自由基能力）由大到小为： 220 MPa＞180 MPa＞140 MPa＞100 MPa＞260 MPa＞对照组＞VC;半抑制浓度的变化趋势与抗氧化能力大小顺序 相反,说明处理压力为220 MPa下的原花青素抗氧化能力最强。     

黏度法测定原花青素聚合度

原花青素是一大类天然多酚化合物的总称,具有很强的抗氧化活性和清除自由基的能力。原花青素的生物活性与聚合度密切相关,为充分发挥原花青素生物活性,找到一种方便、准确、稳定测定聚合度的方法具有重要的意义。本文讨论了黏度法测定原花青素聚合度,利用乌氏黏度计测定不同原花青素样品的流出时间,得到各样品的特性黏度,结合Mark-Houwink方程,确定比例系数K和扩张因子α,求得各样品聚合度。分别利用黏度法和香草醛法对梯度洗脱得到的原花青素样品聚合度进行测定,证明黏度法测定原花青素聚合度是可行的。     

沙棘籽粕低聚原花青素的制备及结构与抗氧化活性分析

目的:以沙棘籽粕为原料，采用超高压前处理、超声波提取工艺制备低聚原花青素并进行结构分析和抗氧化性能测定。方法:通过单因素实验和响应面试验优化沙棘籽粕低聚原花青素制备工艺，采用红外光谱和超高效液相色谱-电喷雾-质谱分析其结构，并以DPPH、ABTS、FRAP法测定其抗氧化性。结果:最优工艺参数为料液比1∶15(g/mL)、超声时间28 min、温度45 ℃、体系pH 2.85，沙棘籽粕原花青素得率为6.556%，平均聚合度为3.35，主要为二聚体、三聚体原花青素及部分黄酮类物质，二聚体包括3类B型二聚体和1类A型二聚体。低聚沙棘籽粕原花青素显示出良好的抗氧化活性，其DPPH、ABTS、FRAP值分别为2.205，1.307和0.8143 mmol Trolox/g DW。结论:低聚沙棘籽粕原花青素有较强抗氧化性，其结构与葡萄籽粕原花青素存在差异。     

不同聚合度葡萄皮原花青素的抗氧化活性

以葡萄皮原花青素为原料,采用溶剂沉淀法根据聚合度进行分级处理。分光光度法测定了不同聚合度葡萄皮原花青素对DPPH.自由基和亚硝酸钠的清除能力,并与VC、BHT进行了比较。结果表明:葡萄皮原花青素对DPPH.自由基和NaNO2清除率与其浓度成正相关,其最大清除率分别为94.61%,92.56%。随着聚合度的增加,其清除能力下降。     

高聚原花青素降解技术研究进展

原花青素是一类广泛存在于自然界中的黄烷-3-醇类化合物,由于大多数从自然界获得的原花青素为带有苯环或长碳链的高聚原花青素,导致其生理活性较弱.通过降解,可以增强原花青素的生理活性以及应用范围.因此,高聚原花青素降解技术成为国内外研究的热点.本文详细整理了国内外有关原花青素高聚体降解技术的文献报道,对化学、生物以及物理降...     

Antioxidant properties of polymeric proanthocyanidins from fruit stones and pericarps of Litchi chinensis Sonn

Fruit stones and pericarps of Litchi chinensis, waste products of the food, were studied as a source of polymeric proanthocyanidins. The structures of the polymeric proanthocyanidins isolated from Litchi chinensis were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) coupled with high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis. The spectra obtained through MALDI-TOF MS analysis revealed that the dominant A-type procyanidin polymers occurred in each polymer length with one or more A-type linkages. The polymeric proanthocyanidins of litchi fruit stones exhibited longer polymer length than those of fruit pericarps, with polymerization degrees up to 20 and 11 for fruit stones and pericarps, respectively. After depolymerization with toluene-??-thiol, HPLC-ESI-MS analysis showed that epicatechin and A-type dimer were the major constituent units, and the mean polymerization degrees were 15.4 and 5.8 for polymeric proanthocyanidins of fruit stones and pericarps, respectively. The antioxidant properties investigated using DPPH, ABTS and FRAP methods showed that the higher polymerization degree of polymeric proanthocyanidins from litchi fruit stones exhibited higher antioxidant activities than those from litchi pericarps.     

不同聚合度板栗壳原花青素的体外抗氧化活性、抑菌活性及其组成分析

为了充分利用板栗壳资源,本文以新鲜板栗壳为原料,分别提取四种不同聚合度的板栗壳原花青素样品F1(70%乙醇粗提物)、F2(AB-8大孔树脂纯化物)、F3(乙酸乙酯萃取物)及F4(水相萃取物),对其进行平均聚合度的测定,分析其体外抗氧化活性和抑菌活性,并采用高效液相色谱和高分辨质谱技术对活性最高级分进行组成分析。结果表明:样品F1、F2、F3及F4的平均聚合度分别为9.42±0.41、4.14±1.06、3.32±0.34、5.07±0.75,最小聚合度样品F3具有最大的抗氧化活性,其对ABTS自由基、羟基自由基与超氧阴离子自由基清除率最大,IC₅₀值分别为11.24、1.18和93.98 μg/mL。抑菌圈试验初筛结果显示,F1对金黄色葡萄球菌表现出抑制作用,对沙门氏菌和大肠杆菌抑制作用不明显。以金黄色葡萄球菌为指示菌,研究四种不同聚合度板栗壳原花青素抑菌效果,结果显示,最小聚合度样品F3对金黄色葡萄球菌抑制作用最大,最小抑菌浓度(MIC)为0.31 mg/mL。高效液相色谱和高分辨质谱结果显示,样品F3中含有没食子酸、儿茶素/表儿茶素和原花青素B型二聚体。实验结果表明,板栗壳原花青素具有较好的抗氧化活性和抑菌活性,且低聚合度原花青素的抗氧化和抑菌效果更为显著,可作为天然抗氧化剂和抑菌剂的原料。     

Air classification of barley flours to produce phenolic enriched ingredients: Comparative study among MEKC-UV, RP-HPLC-DAD-MS and spectrophotometric determinations

The aim of this paper was to use the air classification technology to produce barley flours enriched in phenolic compounds and to obtain naturally enriched ingredients for pasta and bakery industry.Phenolic compounds in barley have been described in literature using different methodologies that are not easily comparable. This paper describes a comparative study between different separative and spectrophotometric methods to determine free and bound phenolic compounds in barley flours and their air classified fractions from three different cultivars grown in the same experimental field.To this end, reversed phase-high performance liquid chromatography, micellar electrokinetic chromatography, and spectrophotometric determinations were applied.The barley phenolic compounds analyzed included mainly catechins and proanthocyanidins as free phenols, and hydroxycinnamic acids and their derivatives as bound phenols.The enriched fractions obtained by air classification showed an increase of free flavan-3-ols of 157-173% compared to whole flour. The same fractions also reported larger concentration of bound phenolic compounds (160-236%) with respect to whole flours. Air classification results a good technique to enrich the flours and to utilize the barley co-products.     

香草醛法测定原花青素物质的量浓度

原花青素的抗氧化活性受聚合度的影响,其平均聚合度可由质量浓度与物质的量浓度计算得出,对原花青素质量浓度的测定方法研究已较为充分,而对原花青素物质的量浓度的测定方法研究较少。原花青素物质的量浓度的测定采用改良香草醛法,即以乙酸作溶剂,香草醛只与原花青素末端黄烷-3-醇发生缩合反应生成红色产物,由红色产物吸光度测得原花青素物质的量浓度。本文通过单因素实验和正交实验考察了硫酸香草醛法测定原花青素物质的量浓度的影响因素,确定了稳定的比色条件,硫酸浓度30％,香草醛浓度1％,反应温度30℃,反应时间15min。在适宜测定条件下,以儿茶素标准品绘制的物质的量浓度的标准曲线为y=3.9593x-0.0737,R2=0.9989,在物质的量浓度为0.025～0.25μmol·mL-1的范围内线性相关性良好。     

黑、红花生衣中原花色素的分析

对黑、红花生衣中的原花色素成分进行考察。通过乙醇溶液提取、有机溶剂萃取分离以及大孔树脂纯化的方法对花生衣色素成分进行分离制备,采用高效液相色谱法对色素中原花色素的含量进行测定,并应用高效液相色谱-质谱联用技术对原花色素成分的组成进行鉴定。黑、红花生衣色素中原花色素的含量分别为29.19%和43.04%。依据质谱信息初步鉴定出红花生衣中含有4 种原花色素二聚体和4 种原花色素三聚体,黑花生衣中含有3 种原花色素二聚体和4 种原花色素三聚体。该法测定原花色素含量简便、快捷,可以较好的鉴定花生衣中原花色素的主要成分。     

Rethinking the Mechanism of the Health Benefits of Proanthocyanidins: Absorption,Metabolism, and Interaction with Gut Microbiota

Proanthocyanidins, as the oligomers or polymers of flavan‐3‐ol, are widely discovered in plants such as fruits, vegetables, cereals, nuts, and leaves, presenting a major part of dietary polyphenols. Although proanthocyanidins exert several types of bioactivities, such as antioxidant, antimicrobial, cardioprotective, and neuroprotective activity, their exact mechanisms remain unclear. Due to the complexity of the structure of proanthocyanidins, such as their various monomers, different linkages and isomers, investigation of their bioavailability and metabolism is limited, which further hinders the explanation of their bioactivities. Since the large molecular weight and degree of polymerization limit the bioavailability of proanthocyanidins, the major effective site of proanthocyanidins is proposed to be in the gut. Many studies have revealed the effects of proanthocyanidins from different sources on changing the composition of gut microbiota based on in vitro and in vivo models and the bioactivities of their metabolites. However, the metabolic routes of proanthocyanidins by gut microbiota and their mutual interactions are still sparse. Thus, this review summarizes the chemistry, absorption, and metabolic pathways of proanthocyanidins ranging from monomers to polymers, as well as the mutual interactions between proanthocyanidins and gut microbiota, in order to better understand how proanthocyanidins exert their health‐promoting functions.     

磁场对新鲜干红葡萄酒原花色素的影响研究

为了缩短葡萄酒陈酿时间,使其品质在较短时间内得到改善,本文通过反相高效液相色谱法分析,研究了葡萄酒经磁场催陈和自然陈酿后,其原花色素的含量和组成单元的变化情况,结果表明,经一定条件的磁场处理后,原花色素的含量、平均聚合度及其组成单元都发生了显著变化,且变化趋势基本符合自然陈酿效果.因此,磁场处理对于加速葡萄酒陈酿、提高葡萄酒品质是具有一定效果的.