雅安藏茶水提醇沉后各组分的物质含量、抗氧化和α-葡萄糖苷酶抑制活性对比分析

为研究藏茶水提物经醇沉后各组分（水提物、醇沉物和上清液）的物质分布情况,对其基本成分、总多酚、总黄酮、茶色素进行全面分析比较,利用高效液相色谱法检测多酚类化合物含量,探究其DPPH · 和ABTS+ · 清除能力以及对α-葡萄糖苷酶消化酶抑制作用差异。结果表明,藏茶水提醇沉物中总糖（17.73 g/100 g）、多糖（16.93 g/100 g）、氨基酸总量（5.89 g/100 g）和茶褐素（49.18 g/100 g）显著（P<0.05）高于上清液,而上清液中总多酚（195.93 mg/g）、总黄酮含量（61.61 mg/g）以及主要的多酚类化合物含量（GA、GC、EGC、C、CA、EC、EGCG、GCG、ECG和CG）均显著（P<0.05）高于醇沉物。体外抗氧化和消化酶抑制活性结果显示藏茶水提醇沉物对DPPH · 和ABTS + · 清除能力低于上清液,但对α-葡萄糖苷酶消化酶抑制作用高于上清液。藏茶水提物经醇沉后上清液具有较强的抗氧化性,而醇沉物具有较强的消化酶（α-葡萄糖苷酶）抑制作用。     

运用高效液相色谱——二极管阵列探测技术与固相萃取法测定啤酒中的多酚物质

由于多酚化合物在啤酒中的含量较低，如果用分光光度法测定其浓度操作比较复杂，啤酒样品要先进行予浓缩。运用固相萃取（SPE）和高效液相色谱（HPLC）——二极管阵列探测技术可分析测定以下多酚类化合物：五倍子、原儿茶素、咖啡酸、对香豆酸、阿魏酸、水杨酸、儿茶素、表儿茶素、五羟黄铜等。这些多酚化合物对啤酒的胶体稳定性和口感稳定性有一定的影响。本方法使用了六种不同的SPE柱和三种不同溶剂洗脱液（乙腈、丙酮、甲醇）。HPLC方法的可行性可通过以下参数如再现性、相对标准偏差（RSD≤10％）、定量限（LOQ）、检出限（LOD）等来进行证实。检测捷克啤酒结果发现其多酚化合物含量变化较大。     

金花藏茶醇提物不同极性部位的多酚成分及体外抗氧化和抗肿瘤活性研究

研究金花藏茶醇提物不同极性部位多酚成分及其抗氧化和抗肿瘤活性。采用液-液萃取金花藏茶醇提物,得到乙酸乙酯层、正丁醇层和水层三个极性部位。采用福林酚法和AlCl3-乙酸钾比色法分别测量醇提物及三个极性部位的总多酚和总黄酮含量,通过高效液相色谱法(HPLC)分析醇提物及三个极性部位的主要多酚类单体含量,并采用DPPH、ABTS⁺自由基清除以及铁离子螯合三种方法比较各类部位的抗氧化作用,通过CCK8法检测不同极性部位对人宫颈癌HeLa细胞的增殖抑制作用。结果表明：金花藏茶乙酸乙酯层含有的多酚和黄酮含量较其它不同极性部位最多,分别为384.65 mg/g和188.82 mg/g,以没食子酸(GA)、没食子儿茶素(GC)和表没食子儿茶素(EGC)为主要酚类成分。抗氧化活性试验显示,对照维生素E,不同极性部位清除DPPH和ABTS⁺自由基能力的大小为,维生素E>乙酸乙酯层>正丁醇层>醇提物>水层,各样品间差异显著(P<0.05);对照EDTA,不同极性部位均有一定的亚铁离子螯和能力,EDTA(IC₅₀为...     

HPLC测定猕猴桃不同部位中的7种多酚类化合物

目的:建立一种能同时测定猕猴桃皮、茎、叶、果肉中7种多酚类化合物的分析方法。方法:多酚类化合物经60%甲醇萃取后,进行HPLC定性定量分析。HPLC检测条件为:流动相A为甲醇,B为0.5%乙酸,检测波长280 nm,采用梯度洗脱程序。结果表明:各多酚类化合物线性相关系数R2≥0.9992,均具有良好线性,加标回收率在95.25%～101.22%,相对标准偏差(RSD)小于2%,方法的检出限在0.002～0.007 mg/g。猕猴桃中含有丰富的多酚类化合物,其中猕猴桃皮、茎、叶、果肉中含量最高的多酚类化合物分别是原儿茶酸、七叶亭、七叶亭、表儿茶素。结论:该方法分离效果好,分析准确度高,重现性好,因此可进一步应用于猕猴桃其他酚类物质的分析;猕猴桃皮中酚类化合物最丰富,可进一步加强利用。     

高效液相色谱法分析中国人参不同部位中多酚类化合物

目的：建立一种同时测定中国人参不同部位中18 种多酚类化合物含量的分析方法,明确多酚类化合物在中国人参不同部位中的分布和含量,为吉林长白山人参资源的深度开发和综合利用提供一定依据。方法：利用高效液相色谱技术,分别对红参根、生晒参根、人参茎、人参叶、人参花和人参须中原儿茶酸、龙胆酸、对羟基苯甲酸、丁香酸、绿原酸、对香豆酸、阿魏酸、间香豆酸、邻香豆酸、肉桂酸、柚皮苷、儿茶素、柚皮素、芒柄花黄素、麦芽酚、橙皮素、甲基香兰素、白藜芦醇18 种多酚化合物和总多酚的含量进行测定分析。结果表明：色谱条件为Symmetry?C18色谱柱（4.6 mm×150 mm,5 μm）,流动相为0.1%磷酸（A）和乙腈（B）,检测波长为230 nm,在此条件下人参样品中18 种多酚化合物可在35 min内得到较好分离,且重复性好（相对标准偏差（relative standard deviation,RSD）≤3.49%）、精密度高（RSD≤3.02%）、稳定性好（RSD≤2.58%）、加标回收结果准确可靠（平均回收率84%～99%,RSD≤5%）。18 种多酚化合物在人参不同部位中的含量差异较大（P＜0.05）,但均呈现出麦芽酚和儿茶素的含量较高。人参不同部位中总多酚含量差异较大（P＜0.05）,红参根、生晒参根、人参茎、人参叶、人参花、人参须中的总多酚含量分别为（69.47±3.25）、（95.04±5.03）、（175.19±3.26）、（256.91±2.81）、（174.40±6.26）、（99.31±2.90） mg/100 g。其中人参叶中的总多酚含量最高（P＜0.05）,红参根中总多酚含量最低。结论：该方法操作简单、高效、准确、可靠,可用于人参多酚的质量控制。     

信阳红红茶的酚类成分及抗氧化能力分析

为探究信阳红红茶的酚类成分及其抗氧化能力,该文采用高效液相色谱（high performance liquid chromatography,HPLC）等方法对9个信阳红红茶中8种儿茶素、6种黄酮类、2种酚酸和水解单宁等酚类成分以及3种嘌呤碱进行定量检测;并采用5种不同方法分别检测分析红茶茶样的体外抗氧化能力。结果表明,在全部或部分信阳红红茶中共检出除没食子儿茶素外的所有酚类成分和3种嘌呤碱。单因素方差分析显示,9个信阳红红茶中部分茶样之间茶多酚、3种茶色素（茶黄素、茶红素和茶褐素）、7种儿茶素、没食子酸、3种黄酮类（花旗松素、槲皮素和山奈酚）、可可碱和水解单宁含量存在极显著性（P＜0.001）差异,以及铁离子还原抗氧化能力（ferric ion reducing antioxidant power,FRAP）、DPPH自由基清除能力和超氧阴离子自由基清除能力（superoxide anion radical scavenging ability,SSA）的体外抗氧化能力存在显著性差异（P＜0.01）。信阳红红茶中表儿茶素没食子酸酯含量最高,其次依次为表没食子儿茶素没食子酸酯、表儿茶素和表没食子儿茶素等儿茶素。芦丁、花旗松素和木犀草素为主要黄酮类化合物,其含量分别为1.39 mg/g～1.79 mg/g、0.59 mg/g～0.74 mg/g和0.53 mg/g～0.75 mg/g。双变量相关性分析显示儿茶素、没食子酸等酚类成分以及茶黄素与FRAP、DPPH自由基清除能力、ABTS+自由基清除能力存在显著（P＜0.05）或高显著（P＜0.01）正相关性,在一定程度上能提高红茶的体外抗氧化能力。     

绞股蓝中6 种多酚化合物的HPLC检测及其醇提液的抗氧化活性

采用高效液相色谱法分析野生（5 叶、7 叶和9 叶3 种生态类型）和人工种植（7 叶）绞股蓝的叶及茎中6 种多酚化合物的含量,并测定样品醇提液的总多酚含量及抗氧化活性。结果表明：色谱条件为色谱柱poroshell 120 PFP（4.6 mm×100 mm,2.7 μm）,流动相1%甲酸（A）和乙腈（B）,检测波长254 nm和350 nm,在此条件下绞股蓝样品中6 种多酚单体可在35 min内得到较好分离,且重复性好（相对标准偏差（relative standard deviation,RSD）≤4.6%）、精密度高（RSD≤2.68%）、稳定性好（RSD≤2.45%）、加标回收结果准确可靠（平均回收率84%～99%,RSD≤4.02%）。6 种多酚单体在不同的绞股蓝样品中含量差异较大,但均呈现出芦丁含量最高,对羟基苯甲酸含量最低。绞股蓝样品醇提液中总多酚及抗氧化活性在不同样品间差异较大,在野生绞股蓝（7 叶）叶中最高（分别为75、39.65、70.48 mg/g）,在其茎中最低（分别为2.81、2.1、3.7 mg/g）。总体而言,绞股蓝的叶中总多酚含量高于茎中,醇提液的抗氧化活性也强于茎。     

回归正交试验优化超声波提取大麦中4 种主要黄酮物质工艺

通过一次回归正交试验,优选出大麦中4 种主要黄酮类物质的最佳超声提取工艺。以儿茶素、杨梅素、槲皮素和山奈酚的含量作为考察指标,以甲醇的体积分数、料液比和超声时间为试验因素,采用本课题组自行优化后的高效液相色谱检测体系对大麦中4 种黄酮类物质的含量进行测定。结果表明：儿茶素、杨梅素、槲皮素和山奈酚在0.005～0.1 μg都呈良好的线性关系,测定方法稳定,可靠。优选超声提取的最佳提取条件为甲醇体积分数50%、料液比1∶20（g/mL）和超声时间60 min。     

溶剂类型对红皮云杉球果多酚类物质的提取及抗氧化能力的影响

利用不同溶剂提取红皮云杉球果中多酚类化合物并测定了三种酚类化合物(总多酚,黄酮和原花青素)的含量和提取物的抗氧化性能力(清除DPPH自由基,清除羟基自由基和还原力)。结果表明,提取溶剂的差异对红皮云杉球果提取物总多酚,黄酮,原花青素含量和抗氧化活性影响显著。红皮云杉球果中含有较高含量的多酚(88.90±1.37)mg/g、原花青素(74.26±0.74)mg/g,和相对较低含量的黄酮类化合物(47.80±0.86)mg/g。原花青素是红皮云杉球果提取物中重要的组成部分,并在红皮云杉球果提取物的抗氧化能力中起到了重要作用。实验中鉴定出的含量较高的绿原酸和儿茶素可以极大地促进了提取物的抗氧化活性。     

HPLC法同时测定白刺果实中8种黄酮成分的含量

建立同时测定白刺果中没食子酸、儿茶素、杨梅素、芦丁、槲皮素、木犀草素、山奈酚和异鼠李素8种黄酮化合物含量的HPLC的方法。采用HYPERSIR C18色谱柱(250 mm×4.6 mm,5μm),柱温35℃,以甲醇-0.1%甲酸水溶液为流动相,进行梯度洗脱,双波长检测(λ1=270 nm,λ2=370 nm),进样量10μL,流速0.8 m L/min。结果:在0~125μg/m L内8种黄酮均有良好的线性关系(R2≥0.999 0),没食子酸、儿茶素、杨梅素、芦丁、槲皮素、木犀草素和山奈酚的平均回收率分别为98.42%,99.19%,90.65%,102.32%,96.51%,98.70%和93.68%,最低检出限依次为0.032,0.052,0.074,0.038,0.059,0.043,0.021和0.036 mg/L。方法精密度RSD≤2.21%(n=6),在此条件下,测得白刺果实中没食子酸、儿茶素、杨梅素、芦丁、槲皮素、木犀草素和山奈酚含量为0.031,0.057,0.064,0.068,0.016和0.038 mg/g。该方法快速简单,重现性好,可为白刺果实质量控制提供定量分析方法。     

基于UPLC/Q-TOF MS/MS的花生油成分分析

采用超高效液相色谱-串联四级杆飞行时间质谱(UPLC/Q-TOF MS/MS)联用仪对花生油甲醇提取液分离检测,分析花生油成分,并通过二级质谱图和标准品确定物质。结果表明:正离子模式下检出86种化合物,鉴定30种物质,其中芥酸、棕榈酰胺、硬酯酰胺、油酸酰胺、11Z-二十二碳二烯酸为已知的花生油成分,亚油酰乙醇胺、亚油酰胺、鞘氨醇、N-油酰乙醇胺、十八碳四烯酸、顺-4-癸二酸等26种物质均为首次被检出;在负离子模式下,共检出27种化合物,鉴定15种物质,其中包括花生油中常见的7种脂肪酸,首次检出(Z)-13-氧-9-十八烯酸、蓖麻油酸、烯油酸、13-羟基十八酸和2(R)-羟基海藻酸5种脂肪酸和其他3种物质。     

食用花卉中的多酚类成分及生物活性研究进展

常见食用花卉中的多酚类化合物主要是黄酮类化合物与酚酸类化合物,这些多酚类化合物具有清除自由基成分的抗氧化活性、抗肿瘤活性、调节心血管疾病,以及防止纤维化、抗炎、防治糖尿病等生物活性。文章对近年来国内外对食用花卉中多酚类成分的相关研究进行了总结梳理和评述。     

超高效液相色谱-串联质谱法测定甘蔗中11种多酚类物质

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)测定甘蔗中11种多酚类物质含量的方法.样品经甲醇超声提取,采用UPLC-MS/MS进行分析检测,电喷雾负离子电离(ESI-),多反应监测(MRM)检测,外标法定量.该方法在5～200μg/L范围内线性良好(r2>0.999),检出限为0.5～17.0μg/kg.在样...     

圆铃1号枣多酚的提取及抗氧化活性分析

以圆铃1号枣为试验材料,通过单因素和正交试验优化其多酚的提取条件,并对其酚酸组成、体外抗氧化能力进行初步研究。结果表明:乙醇体积分数为60%、提取温度为60℃、料液比1∶16(g/mL)、提取时间20 min时,多酚提取量最大,达到(10.69±0.078)mg/g。采用高效液相色谱法鉴定出6种酚酸,分别为芦丁、香豆素、咖啡酸、肉桂酸、(+)-儿茶素、绿原酸,其中芦丁的含量最高,为(17.09±0.48)mg/100 g DW。其多酚提取物的DPPH·清除能力为(17.96±0.95)mg Trolox/g、ABTS+·清除能力为(27.79±3.06)mg Trolox/g、亚铁离子还原力为(32.89±2.17)mg Trolox/g,是一种极具潜力的天然抗氧化剂。     

Isolation and characterization of functional components from peel samples of six potatoes varieties growing in Ontario

Potato processing industry generates high amounts of peel as a byproduct. It is a good source of several beneficial functional ingredients including antioxidant polyphenols. A study was undertaken to estimate the polyphenolic content and antioxidant properties of peel samples from potatoes grown in Ontario, Canada. Peel samples from Vivaldi, Yukon Gold, Dakota Pearl, FL 1533, Siècle and Purple Majesty varieties of potatoes were extracted with methanol and analyzed for their polyphenolic contents and antioxidant properties using Folin–Ciocalteu reagent, ferric-ion reducing antioxidant power (FRAP), Trolox equivalent (6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid) and free radical scavenging activity (FRSA). Specific phenolic compounds present in potato peel samples were measured using HPLC. Results of total phenolic compounds from both spectrophotometric and chromatographic analyses were statistically compared to validate methods of extraction and determination. Red-colored potato varieties; Siècle and Purple Majesty, had the highest antioxidant potential compared to other varieties. Chromatographic data showed differences in the amounts, but not in types of phenolic compounds in the potato peel samples.     

Quantification of Almond Skin Polyphenols by Liquid Chromatography-Mass Spectrometry

ABSTRACT:  Reverse phase HPLC coupled to negative mode electrospray ionization (ESI) mass spectrometry (MS) was used to quantify 16 flavonoids and 2 phenolic acids from almond skin extracts. Calibration curves of standard compounds were run daily and daidzein was used as an internal standard. The inter-day relative standard deviation (RSD) of standard curve slopes ranged from 13% to 25% of the mean. On column (OC) limits of detection (LOD) for polyphenols ranged from 0.013 to 1.4 pmol, and flavonoid glycosides had a 7-fold greater sensitivity than aglycones. Limits of quantification were 0.043 to 2.7 pmol OC, with a mean of 0.58 pmol flavonoid OC. Mean inter-day RSD of polyphenols in almond skin extract was 6.8% with a range of 4% to 11%, and intra-day RSD was 2.4%. Liquid nitrogen (LN₂) or hot water (HW) blanching was used to facilitate removal of the almond skins prior to extraction using assisted solvent extraction (ASE) or steeping with acidified aqueous methanol. Recovery of polyphenols was greatest in HW blanched almond extracts with a mean value of 2.1 mg/g skin. ASE and steeping extracted equivalent polyphenols, although ASE of LN₂ blanched skins yielded 52% more aglycones and 23% less flavonoid glycosides. However, the extraction methods did not alter flavonoid profile of HW blanched almond skins. The recovery of polyphenolic components that were spiked into almond skins before the steeping extraction was 97% on a mass basis. This LC-MS method presents a reliable means of quantifying almond polyphenols.     

Bioactive dietary polyphenols inhibit heme iron absorption in a dose-dependent manner in human intestinal Caco-2 cells

Abstract: Although heme iron is an important form of dietary iron, its intestinal absorption mechanism remains elusive. Our previous study revealed that (‐)‐epigallocatechin‐3‐gallate (EGCG) and grape seed extract (GSE) markedly inhibited intestinal heme iron absorption by reducing the basolateral iron export in Caco‐2 cells. The aim of this study was to examine whether small amounts of EGCG, GSE, and green tea extract (GT) could inhibit heme iron absorption, and to test whether the inhibitory action of polyphenols could be offset by ascorbic acid. A heme‐⁵⁵Fe absorption study was conducted by adding various concentrations of EGCG, GSE, and GT to Caco‐2 cells in the absence and presence of ascorbic acid. Polyphenolic compounds significantly inhibited heme‐⁵⁵Fe absorption in a dose‐dependent manner. The addition of ascorbic acid did not modulate the inhibitory effect of dietary polyphenols on heme iron absorption when the cells were treated with polyphenols at a concentration of 46 mg/L. However, ascorbic acid was able to offset or reverse the inhibitory effects of polyphenolic compounds when lower concentrations of polyphenols were added (≤ 4.6 mg/L). Ascorbic acid modulated the heme iron absorption without changing the apical heme uptake, the expression of the proteins involved in heme metabolism and basolateral iron transport, and heme oxygenase activity, indicating that ascorbic acid may enhance heme iron absorption by modulating the intracellular distribution of ⁵⁵Fe. These results imply that the regular consumption of dietary ascorbic acid can easily counteract the inhibitory effects of low concentrations of dietary polyphenols on heme iron absorption but cannot counteract the inhibitory actions of high concentrations of polyphenols. Practical Application: Bioactive dietary polyphenols inhibit heme iron absorption in a dose‐dependent manner. The small amounts of polyphenolic compounds present in foods are capable of reducing heme iron transport across the intestinal enterocyte. However, the inhibitory effects of dietary polyphenolic compounds on heme iron absorption can be offset by ascorbic acid and can possibly be avoided by decreasing the consumption of polyphenols while simultaneously taking ascorbic acid.     

大麦发芽过程中不同存在形式的酚类物质及其抗氧化活性变化

以甘啤4号为原料,研究发芽过程中4类多酚物质提取物的含量及其抗氧化活性的变化,采用的评价指标为DPPH自由基清除活性、ABTS自由基清除活性和铁还原力,同时利用HPLC法依次检测4类粗多酚中9种单体酚酸的含量及其变化。试验结果表明:发芽显著影响大麦粗多酚、单体酚酸的种类和含量及其抗氧化活性。游离粗多酚在原麦和萌发过程中始终占总粗多酚含量的最大比例,并且其综合抗氧化活力也显著高于其它3类粗多酚提取物。4类粗多酚提取物和各单体酚酸的总含量及抗氧活性总是原麦高于各萌发时期,在浸泡阶段统一显著下降,萌发后期又有显著升高。相关性分析表明,4类粗多酚的铁还原能力、清除DPPH和ABTS自由基的能力均与其含量密切相关,与粗多酚显著相关的单体酚酸,同样显著影响着其抗氧化活性。阿魏酸、儿茶素、对香豆酸是主要的活性酚酸。     

Bioavailability study of a polyphenol‐enriched extract from Hibiscus sabdariffa in rats and associated antioxidant status

The aqueous extracts of Hibiscus sabdariffa have been commonly used in folk medicine. Nevertheless, the compounds or metabolites responsible for its healthy effects have not yet been identified. The major metabolites present in rat plasma after acute ingestion of a polyphenol‐enriched Hibiscus sabdariffa extract were characterized and quantified in order to study their bioavailability. The antioxidant status of the plasma samples was also measured through several complementary antioxidant techniques. High‐performance liquid chromatography coupled to time‐of‐flight mass spectrometry (HPLC‐ESI‐TOF‐MS) was used for the bioavailability study. The antioxidant status was measured by ferric reducing ability of plasma method, thiobarbituric acid reactive substances assay, and superoxide dismutase activity assay. Seventeen polyphenols and metabolites have been detected and quantified. Eleven of these compounds were metabolites. Although phenolic acids were found in plasma without any modification in their structures, most flavonols were found as quercetin or kaempferol glucuronide conjugates. Flavonol glucuronide conjugates, which show longer half‐life elimination values, are proposed to contribute to the observed lipid peroxidation inhibitory activity in the cellular membranes. By contrast, phenolic acids appear to exert their antioxidant activity through ferric ion reduction and superoxide scavenging at shorter times. We propose that flavonol‐conjugated forms (quercetin and kaempferol) may be the compounds responsible for the observed antioxidant effects and contribute to the healthy effects of H. sabdariffa polyphenolic extract.