HPLC-Q-TOF-MS-MS测定桑椹中多酚类物质

采用高效液相色谱与四极杆飞行时间串联质谱（high performance liquid chromatography of quadrupole time of flight-tandem mass spectrometry,HPLC-Q-TOF-MS-MS）联用技术定性检测桑椹中多酚类物质,新鲜桑椹样品经体积分数80%丙酮溶液超声辅助提取15 min后,采用C18固相萃取小柱分离纯化,纯化后的样品进行质谱鉴定。采用HPLC-Q-TOF-MS-MS对多酚进行分析：初步鉴定了桑椹中存在14 种多酚类物质,主要以酚酸、花色苷和黄酮的形式存在。其中6 种酚酸：3-O-咖啡酰奎宁酸、4-O-咖啡酰奎宁酸、二聚绿原酸、二聚4-O-咖啡酰奎宁酸、绿原酸顺式异构体、3,5-O-二咖啡酰基奎宁酸。4 种花色苷：飞燕草-3-半乳糖苷、飞燕草-3-葡萄糖苷、矢车菊-3-葡萄糖苷、矢车菊-3-芸香糖苷;3 种黄酮：芦丁、鞣花酸己糖苷和槲皮素3-O-（6’-O-丙二酰）葡萄糖苷,1 种白藜芦醇衍生物。HPLC-Q-TOF-MS-MS可以鉴定出桑椹的多酚类物质。     

桂花酶解物中酚类物质及其抗氧化活性研究

运用LC-MS/MS对桂花酶解物中的酚类物质进行研究,发现桂花酶解物中含有36种酚类物质,包括单咖啡酰基奎宁酸、咖啡酸4-O-葡萄糖苷、5-O-对香豆酰基奎宁酸、4-O-对香豆酰基奎宁酸、木犀草素-7-O-6″-丙二酰基葡萄糖苷、麦角甾苷、异麦角甾苷等物质。抗氧化活性研究发现,桂花酶解物浓度大于0.8 mg/m L时,对ABTS+、DPPH·自由基清除率达90%以上,均显著高于芦丁(p0.05),略低于Trolox;桂花酶解物的还原力为3.0左右,显著高于芦丁的1.0左右(p0.05),稍高于Trolox;桂花酶解物的TEAC和ORAC值分别为648.66μmol Trolox/g和813.53μmol Trolox/g,均显著高于芦丁(p0.05);桂花酶解物的ABTS+、DPPH·自由基清除能力和还原力与总酚含量均呈显著的线性正相关。     

采用HPLC-DAD-ESIMS技术鉴定紫山药中的花色苷成分

采用大孔树酯对浙江台州黄岩紫山药中的花色苷进行分离,并用高压液相色谱-二极管阵列检测-质谱检测技术对其中的主要花色苷进行结构鉴定。通过差异pH法分析紫山药中花色苷的含量为28.8mg/kg。紫山药中4种主要的花色苷可能是:矢车菊素-3-葡萄糖苷或半乳糖苷的双咖啡酸酰化物,矢车菊素-3-二糖苷的芥子酸酰化物,矢车菊素-3-二糖苷阿魏酸的酰化物,芍药色素-3-二糖苷的芥子酸酰化物。     

紫色马铃薯皮花色苷的结构鉴定

为纯化、鉴定紫色马铃薯(Solanum tuberosum L.)皮中的花色苷组分,采用2%柠檬酸水和D101大孔树脂对紫色马铃薯皮花色苷进行提取分离,利用高效液相色谱外标峰面积法测定花色苷的含量为207.33 mg/g冻干粉,并通过HPLC-DAD-ESI-MS/MS联用技术鉴定紫色马铃薯皮花色苷的组成。紫色马铃薯皮花色苷冻干粉共检出14种花色苷,以矮牵牛素-3-O-对香豆酰芸香糖苷-5-O-葡萄糖苷含量最为丰富。所有花色苷中,4种花色苷以花色素-3-O-芸香糖苷-5-O-葡萄糖苷形式存在,9种花色苷以花色素-3-O-对香豆酰(或咖啡酰或阿魏酰)芸香糖苷-5-O-葡萄糖苷的形式存在,除此之外,存在一种花色苷可能采取C3,C7-位双糖基取代。紫色马铃薯皮中所含花色苷绝大多数为酰化双糖基取代花色苷,结构稳定,因而紫色马铃薯皮作为一种食品加工副产物具有良好的开发前景和利用价值。     

高效液柑色谱-串联质谱测定砀山酥梨中的酚类物质

本文研究了高效液相色谱．电喷雾串联质谱定性、定量检测砀山酥梨及其制品中的酚类物质。样品中的酚类物质在70min内得到分离，酚类物质由色谱的保留时间、质谱信息和参考文献确定。质谱检测在负离子模式下，利用全扫描模式、多反应检测模式和中性丢失模式进行。本研究在砀山酥梨中共检出酚类27种，主要酚类物质是绿原酸，含量为180mg／L，其次为熊果苷、没食子酸、咖啡酸、咖啡奎宁酸、表儿茶素、儿茶素、柚（皮）苷、芦丁、槲皮素．葡萄糖苷、槲皮素-半乳糖苷、槲皮素-鼠李糖苷、香豆酸-葡萄糖苷、槲皮紊-戊糖苷、鼠李糖素-葡萄糖苷、槲皮索等。     

高效液相色谱-串联质谱测定砀山酥梨中的酚类物质

本文研究了高效液相色谱-电喷雾串联质谱定性、定量检测砀山酥梨及其制品中的酚类物质。样品中的酚类物质在70min内得到分离,酚类物质由色谱的保留时间、质谱信息和参考文献确定。质谱检测在负离子模式下,利用全扫描模式、多反应检测模式和中性丢失模式进行。本研究在砀山酥梨中共检出酚类27种,主要酚类物质是绿原酸,含量为180mg/L,其次为熊果苷、没食子酸、咖啡酸、咖啡奎宁酸、表儿茶素、儿茶素、柚(皮)苷、芦丁、槲皮素-葡萄糖苷、槲皮素-半乳糖苷、槲皮素-鼠李糖苷、香豆酸-葡萄糖苷、槲皮素-戊糖苷、鼠李糖素-葡萄糖苷、槲皮素等。     

不同花色苷代表性成分的分离鉴定及体外抗氧化活性

本实验以紫甘薯、黑枸杞、黑加仑和桑葚花色苷提取物为原料,制备其单体花色苷组分并研究其体外抗氧化性质。选取每种花色苷中含量较高,分子量居中,具有代表性的单体化合物作为目标组分,采用高速逆流色谱制备分离四种来源的花色苷。选用甲基叔丁基醚-正丁醇-乙腈-水-三氟乙酸作为溶剂体系,流速设定为5 mL/min,转速为850 r/min,分离得到高纯度花色苷单体化合物。采用分光光度法、HPLC-MS法分析测定花色苷含量及主要组成,用DPPH自由基、羟自由基清除能力和总还原力的测定分析其体外抗氧化活性。结果表明,四种来源的花色苷中代表性的成分依次为芍药素-3-咖啡酰-阿魏酰槐糖苷-5-葡萄糖苷、矮牵牛素-3-O-对香豆酰芸香糖苷-5-O-葡萄糖苷、矢车菊-3-芸香糖苷和矢车菊-3-O-葡萄糖苷,它们均具有良好的体外抗氧化活性。     

高效液相色谱-串联质谱法测定各生长期紫苏中酚类物质的含量

目的：建立一种简单、快速、准确的高效液相色谱-串联质谱法,同时分离与检测紫苏叶、茎和根中酚类化合物含量,探讨紫苏各部位酚类物质的累积规律,为确定紫苏各部位最佳采收时期提供依据。方法：对紫苏进行人工栽培,样品分期采集,采集后的样品经乙醇提取,采用高效液相色谱-串联质谱法进行分析,对影响色谱、质谱的重要参数进行优化,通过对照标准物质的保留时间及质谱分析,确定相应的化合物;通过标准曲线法定量,以其中13 种酚类化合物为主要参考指标,观察它们在各部位的动态含量变化。结果：鉴定出化合物：咖啡酸、咖啡酸-3-O-葡萄糖苷、迷迭香酸、迷迭香酸-3-O-葡萄糖苷、木犀草素、木犀草素-7-O-葡萄糖苷、木犀草素-7-O-葡萄糖苷酸、木犀草素-7-O-二葡萄糖苷酸、芹菜素、芹菜素-7-咖啡酰基葡萄糖苷、芹菜素-7-O-二葡萄糖苷、野黄岑素-7-O-二葡萄糖苷、迷迭香酸甲酯,以上化合物中酚酸及其糖苷化合物含量呈先降低,至结果期急剧上升达到最大,黄酮及其糖苷化合物含量则递增至结果期达到最大。其中鉴定出迷迭香酸和木犀草素-7-O-葡萄糖苷酸分别在结果期达到最大,含量分别为21.41 mg/g和19.89 mg/g,结果期叶部位总酚类含量达到最大,含量为47.50 mg/g。结论：通过对紫苏各个部位不同采收时期黄酮、黄酮糖基化、酚酸的动态变化、总含量变化和部位成分分布的研究,对紫苏酚类资源的利用提供参考依据。     

野生黑枸杞果实中酚类物质的组成分析

以产自宁夏的野生黑枸杞鲜果为实验材料,采用高效液相色谱-三重四极杆串联质谱联用仪对黑枸杞果实中的酚类物质组成进行定性、定量分析。结果显示,黑枸杞果实富含酚类物质,共鉴定到花色苷类物质20 种,非花色苷酚类物质16 种。其中,最主要的花色苷为甲基花翠素-3,5-O-双葡萄糖苷和一些6-O-香豆酰化衍生的3-O-单糖苷花色苷,而最主要的非花色苷酚类物质为绿原酸等一系列羟基肉桂酸,与葡萄、蓝莓等富含酚类物质的深色水果有极大不同,具有典型的种属特异性。本研究将为黑枸杞的鲜果消费以及产品开发提供一定的理论基础。     

‘紫娟’茶花色苷的分离鉴定

依次以MCI gel CPH 20P(75~150μm)树脂和Sephadex~(TM) LH-20葡聚糖凝胶为层析柱填料,对‘紫娟’茶花色苷进行分离纯化,采用5%乙酸-甲醇溶液和5%乙酸溶液对花色苷提取液梯度洗脱,得到6种花色苷组分。采用薄层层析、高效液相色谱及高效液相色谱-电喷雾-串联质谱对‘紫娟’茶花色苷组成成分进行研究。结果表明:从‘紫娟’茶鲜叶中分离出的花色苷为飞燕草素-3-O-半乳糖苷、矢车菊素-3-O-半乳糖苷、飞燕草素-3-O-(6-(Z)对香豆酸)吡喃半乳糖苷、矢车菊素-3-O-(6-(Z)对香豆酸)吡喃半乳糖苷、飞燕草素-3-O-(6-(E)对香豆酸)吡喃半乳糖苷、矢车菊素-3-O-(6-(E)对香豆酸)吡喃半乳糖苷。     

Phenolic compounds in Chinese purple yam and changes during vacuum frying

Phenolic compounds and their changes during vacuum frying were investigated for a Chinese purple yam. Three cyanidin derivatives and one peonidin derivative were tentatively identified by HPLC–DAD–ESIMS analysis; sinapic acid and ferulic acid were identified by HPLC–DAD analysis with authentic chemicals. There were 31.0 mg/100 g (dry weight, DW) of total anthocyanin (ACN) and 478 mg/100 g DW of total phenolic content (TPC) in the fresh yam. Sinapic acid and ferulic acid were 135 and 31.3 mg/100 g DW respectively. The blanching process caused about 60% of ACN, and 30–50% of phenolic acids and TPC to be lost, which showed that anthocyanins were most vulnerable during blanching. The retention rate of the phenolic compounds during vacuum frying was 60–69%, indicating it was a practical technology for purple yam processing, on account of its impact on the phenolic compounds stability.     

De-oiled rapeseed and a protein isolate: characterization of sinapic acid derivatives by HPLC–DAD and LC–MS

De-oiled rapeseed is a rich source of proteins and phenolic compounds. The phenolic compounds, namely sinapic acid derivatives (SAD), could occur as free sinapic acid, esterified (as sinapine, the choline ester of sinapic acid) and decarboxylated (as canolol) forms. Rapeseed protein preparations containing very low phenolic compounds have been the focus of our ongoing research. A precipitated rapeseed protein isolate is investigated for SAD such as sinapine, sinapoyl glucose, canolol using HPLC–DAD and LC–MS. Profile of the phenolic compounds of de-oiled rapeseed, press cakes and the precipitated protein isolate are compared. HPLC–DAD analysis indicated SAD; particularly sinapine is the main phenolic compound of all the substrates. The protein derivation process did not remarkably alter the profile of the investigated protein isolate.     

超声-微波协同萃取紫参薯花青素工艺

以海南产紫参薯为原料,采用Box-Behnken中心组合试验设计优化紫参薯花青素的超声-微波协同萃取工艺。分别采用时间模式与恒温模式两种方法,在单因素试验基础上,以花青素提取率为响应值,采用三因素三水平的响应面分析法进行试验。结果表明：恒温模式时,在额定超声功率50W、料液比1:48(g/mL)、萃取时间283s、微波控制温度46℃工艺条件下,紫参薯提取率达79.38%,较时间模式下高10.63%,超声-微波协同萃取的总花青素质量浓度为48.42mg/L,即4.37mg/g。     

LC–MS analysis of anthocyanins from purple corn cob

Liquid chromatography coupled with diode array spectrophotometry and mass spectrometry detection (LC–DAS–MS) has been applied to the study of the anthocyanin composition of a commercial extract from purple corn cob used as a colourant additive in the food industry. Nine different anthocyanins were isolated using semipreparative HPLC and identified by LC–MS and hydrolytic techniques. Useful information for the identification of compounds was also obtained from their fragmentation patterns (MS–MS spectra). Six of these anthocyanins seem to be present in the original cob, namely cyanidin‐3‐glucoside, pelargonidin‐3‐glucoside, peonidin‐3‐glucoside and their respective malonyl derivatives. The other three are produced during the industrial extraction process and have been identified as the corresponding ethylmalonyl derivatives. © 2002 Society of Chemical Industry     

HD/GC-MS法测定辣木树不同部位挥发性香气成分的研究

采用水蒸汽蒸馏(HD)结合气相色谱-质谱(GC-MS)分析辣木叶、茎和根的挥发性香气成分,用峰面积归一化法计算各组分的相对含量。辣木叶中共鉴定出43种化合物,主要成分为苯乙醛(14.52%)、苯甲醛(1.9%)、2-己烯醛(1.52%)、棕榈酸甲酯(3.41%)、异硫氰酸甲氧基甲酯(2.03%)、邻苯二甲酸正丁异辛酯(1.57%)、二氢猕猴桃内酯(1.41%)、棕榈酸(13.91%)。辣木茎中共鉴定出16种化合物,主要成分为苯甲醛(15.69%)、棕榈酸(9.47%)和亚油酸(7.91%)。辣木根中共鉴定出13种化合物,主要成分为苯乙腈(36.94%)、苯甲醛(18.21%)和异硫氰酸苄酯(15.96%)。     

响应面法优化紫山药花青苷提取工艺及其抗氧化活性

以紫山药为实验材料,以酸性乙醇为提取溶剂,通过Box-Behnken响应面法及Design-Expert 8.0.6分析软件建立二次多项式数学模型,优化紫山药花青苷的提取工艺。同时,对紫山药花青苷清除·OH和O2－·的能力进行分析研究。结果表明,5 种单因素对花青苷得率影响大小的顺序为盐酸质量分数＞提取时间＞乙醇体积分数＞液料比＞提取温度,紫山药花青苷最佳提取工艺参数为提取温度80 ℃、提取时间3.5 h、液料比25∶1（mL/g）、乙醇体积分数70%、盐酸质量分数18‰。在上述最佳条件下,紫山药花青苷平均得率达到4.966 mg/g,相对标准偏差为0.29%,与数学模型理论得率的相对误差小于1.0%。抗氧化实验结果表明,紫山药花青苷对·OH及O2－·具有较好的清除能力,其抗氧化能力强于VC。     

Phenolic compound profiles in selected Queensland red wines at all stages of the wine-making process

The phenolic profiles of Queensland red wines (two Cabernet Sauvignons and one Shiraz) from different stages of wine-making were studied. Samples were taken at crush, after the primary and malolactic fermentations, post-oaking, and post-bottling, and then extracted and separated into aqueous and organic fractions using liquid–liquid extraction and solid-phase extraction, and analysed by HPLC-DAD-MS. About 75% of the phenolic compounds were extracted into the aqueous fraction, with malvidin-3-glucoside and derivatives as the main components. The major non-anthocyanin phenolic compounds (∼25%) included gallic acid, syringic acid, ethyl gallate, caftaric acid, coutaric acid, caffeic acid, coumaric acid, catechin, and quercetin. The polymerisation of anthocyanins was shown to occur progressively throughout the wine-making process. Most of the 25 identified phenolic compounds had highest concentrations during the fermentation stage, and stabilised or slowly decreased thereafter. There were weak and insignificant correlations (P > 0.05) between individual phenolic compounds and the total antioxidant activities (ORAC). Four groups of phenolic compounds (anthocyanins, hydroxybenzoic acids, flavanols and hydroxycinnamic acids) each showed some correlation with the total antioxidant activity, as did the total polyphenol content, suggesting that the antioxidant properties of red wine are due to a complex mixture of phenolic compounds that vary in composition throughout the wine-making process.     

Simultaneous evaluation of intact glucosinolates and phenolic compounds by UPLC-DAD-MS/MS in Brassica oleracea L. var. botrytis

A method for the simultaneous determination of intact glucosinolates and main phenolic compounds (flavonoids and sinapic acid derivatives) in Brassica oleracea L. var. botrytis was proposed. A simplified sample extraction procedure and a UPLC separation were carried out to reduce the total time of analysis. B. oleracea samples were added with internal standards (glucotropaeolin and rutin), and extracted with boiling methanol. Crude extracts were evaporated under nitrogen, redissolved in mobile phase and analysed by UPLC with double detection (ESI⁻-MRM for glucosinolates and flavonoids, and DAD for main sinapic acid derivatives). The proposed method allowed a satisfactory quantification of main native sinapic acid derivatives, flavonoids and glucosinolates with a reduced time of analysis.     

提高黑米花色苷颜色稳定性辅色剂的筛选及其作用机制

选用7 种酚类化合物和有机酸（表儿茶素、咖啡酸、迷迭香酸、绿原酸、草酸、苹果酸、丁香酸）,评价其在pH 3.0和5.0条件下对黑米花色苷颜色稳定性的影响,以辅色效果和热稳定性为指标筛选最佳辅色剂,并在pH 3.0条件下探究其最佳添加浓度,随后借助红外光谱、分子对接及分子动力学分析其保护作用机制。结果表明,除苹果酸外,其余6 种辅色剂均在pH 3.0和pH 5.0时对黑米花色苷具有辅色效果并能提高其热稳定性,其中在pH 3.0条件下添加迷迭香酸的效果最佳;在所添加质量浓度范围内（0.1～4.0 mg/mL）,迷迭香酸质量浓度越高对黑米花色苷的辅色效果越好。当迷迭香酸质量浓度为2.0 mg/mL时对黑米花色苷的热稳定性的保护作用最好。傅里叶红外光谱、分子对接及分子动力学结果表明,迷迭香酸可通过氢键和π-π堆积相互作用力与花色苷结合,从而提高黑米花色苷的稳定性。因此,在实际应用中可通过添加迷迭香酸提高黑米花色苷的颜色稳定性。     

Optimisation,characterisation and quantification of phenolic compounds in olive cake

The phenolic compounds in extracts from pressed olive cake were investigated. Free phenolic compounds were extracted from olive cake using methanol. To liberate bound phenolic compounds, the olive cake was subjected to basic and acidic hydrolysis followed by methanol extraction. The individual phenolic compounds and antioxidant activity of the extracts were determined. The highest total phenolic content and antioxidant activity were obtained using methanol extraction for 12 h at 70 °C. The RP-HPLC profiles for full-fat and defatted olive cake showed that protocatechuic acid, hydroxybenzoic acid, sinapic acid, p-coumaric acid, rutin and hesperidin were the predominant free phenolic compounds. Meanwhile, syringic acid, sinapic acid, caffeic acid and protocatechuic acid were the predominant bound phenolic acids. A positive correlation was observed between total phenolic content and antioxidant activity. The results indicated that most of the phenolic compounds in olive products were present in their free forms (75–90% of total phenolic content), while bound phenolic compounds were only a small proportion (10–25%) of total phenolic content.