On the reaction of L-ascorbic acid with propylamine under various conditions: quantification of the main products by HPLC/DAD

 The reaction of _L-ascorbic acid (AA) with proteins (protein ascorbylation) has a considerable impact on food processing and health. So far four products have been isolated and identified which can be formed from AA and lysine derivatives. Thus, 2-deoxy-2-(propylamino)ascorbic acid, 3-deoxy-3-(propylamino)ascorbic acid, oxalic acid monopropylamide and oxalic acid dipropylamide were synthesized and an HPLC system for their separation and quantification was developed. Then, mixtures of AA and propylamine, as a model compound for lysine derivatives, were reacted under various conditions and product yields were determined in relation to reaction time, temperature, amine concentration and pH value. The results were discussed in detail and can help to evaluate the contribution of the four products to protein and lysine ascorbylation under different conditions. Received: 2 September 1997 / Revised version: 27 November 1997     

On the reaction of L-ascorbic acid with propylamine under various conditions: quantification of the main products by HPLC/DAD

 The reaction of _L-ascorbic acid (AA) with proteins (protein ascorbylation) has a considerable impact on food processing and health. So far four products have been isolated and identified which can be formed from AA and lysine derivatives. Thus, 2-deoxy-2-(propylamino)ascorbic acid, 3-deoxy-3-(propylamino)ascorbic acid, oxalic acid monopropylamide and oxalic acid dipropylamide were synthesized and an HPLC system for their separation and quantification was developed. Then, mixtures of AA and propylamine, as a model compound for lysine derivatives, were reacted under various conditions and product yields were determined in relation to reaction time, temperature, amine concentration and pH value. The results were discussed in detail and can help to evaluate the contribution of the four products to protein and lysine ascorbylation under different conditions. Received: 2 September 1997 / Revised version: 27 November 1997     

高效液相色谱法测定车厘子中果糖、葡萄糖及蔗糖含量

采用高效液相色谱法(HPLC)测定车厘子中果糖、葡萄糖及蔗糖的含量。测定方法：Shodex SUGAR系列KS-801(钠型)色谱柱(8 mm×300 mm,6 μm)、流动相为超纯水,流速0.8 mL/min,柱温80 ℃,示差折光检测器(RID)温度30 ℃,进样量20 μL,外标法定量。该法对果糖、葡萄糖和蔗糖测定的平均回收率分别为99.96%、100.30%、99.26%,相对标准偏差(RSD)分别为1.54%、0.49%、0.48%,检出限分别为3.50 μg/mL、4.88 μg/mL、7.50 μg/mL,果糖、葡萄糖和蔗糖的标准曲线相关系数均在0.999以上(n=5)。该法可快速准确的对果糖、葡萄糖和蔗糖定性、定量分析。结果表明,车厘子果肉中果糖、葡萄糖、蔗糖的含量分别为5.69%、5.83%、0.24%。     

高效液相色谱法测定盐酸精氨酸葡萄糖注射液中盐酸精氨酸的含量

目的建立测定盐酸精氨酸葡萄糖注射液中盐酸精氨酸含量的方法。方法使用高效液相色谱法,色谱条件为:Shim-Pack-CLC-NH2柱;流动相为乙腈-磷酸盐缓冲液(50:50);流速为1 ml/min;检测波长为200 nm。结果线性范围为0.04-0.2 mg/ml;相关系数R=0.999 8;回收率为99.9%(RSD=0.30%,n=9)。结论此方法重复性好,结果准确,可用于测定盐酸精氨酸葡萄糖注射液中盐酸精氨酸的含量。     

Investigation of proanthocyanidins by HPLC with electrospray ionization mass spectrometry

Received: 1 June 1999     

赖氨酸/葡萄糖美拉德反应产物对丙烯酰胺生成的抑制作用

建立天冬酰胺/葡萄糖模式反应体系,运用高效液相色谱法、自由基清除法等手段研究赖氨酸/葡萄糖美拉德反应产物对该模式体系中丙烯酰胺生成量及体系抗氧化性的影响。结果显示:高、低分子量的赖氨酸/葡萄糖美拉德反应产物(H-LGP和L-LGP)均能显著降低模式反应体系中的丙烯酰胺生成量,其中H-LGP和L-LGP的添加量为10 mg/mL时,对丙烯酰胺生成的抑制率最大,分别为32.0%和31.4%。H-LGP和L-LGP(均为10mg/mL)的添加还可显著提高反应体系清除自由基DPPH和ABTS的能力。结论:赖氨酸/葡萄糖美拉德反应产物(LGP)能够显著抑制天冬酰胺/葡萄糖模式反应体系中丙烯酰胺的生成,且高浓度的LGP能够显著提高反应体系的抗氧化性。     

Identification of the Polyphenols in Barley and Beer by HPLC/MS and HPLC/Electrochemical Detection

Barley polyphenols were isolated using acetone/water (70/30) followed by Sephadex LH-20 chromatography. HPLC/Electrospray mass spectrometry showed the presence of proanthocyanidin dimers, trimers, tetramers, and pentamers. HPLC/electrochemical detection was used to survey the contents of these compounds in a range of barley varieties. Principal components analysis showed that the naked barley varieties Morrell, and to a lesser extent Namoi, were different from the other barley varieties. Beer polyphenol extracts were prepared using Sephadex LH-20 chromatography. A large number of proanthocyanidin dimers and trimers could be detected using HPLC/MS. HPLC/electrochemical detection was used to survey a range of beer types. Compounds detected included catechin, epicatechin, gallocatechin, epigallocatechin, a number of proanthocyanidin dimers and trimers, and a number of phenolic acids. The peaks removed by PVPP have been determined. Principal components analysis was used to identify those compounds which distinguished the beer types. The first principal component was due to prodelphinidin B3, catechin, gallocatechin and two unidentified compounds which were removed by PVPP and the second principal component was due to phenolic acids. Efforts to identify the compounds removed by PVPP have commenced.     

葡萄糖-甘氨酸美拉德反应产物对脂肪氧合酶的抑制作用研究

以葡萄糖和甘氨酸为原料制备美拉德反应产物（Glu/Gly-MRPs）,研究其对大豆脂肪氧合酶（LOX）的抑制作用以及机理。结果表明:随着反应中甘氨酸浓度、反应初始pH、反应温度和反应时间的增大,Glu/Gly-MRPs的褐变程度加深,pH下降,对LOX的抑制作用增强;当甘氨酸浓度大于0.6mol/L、反应体系初始pH高于8.0、反应温度高于110℃、反应时间长于3h时,MRPs对LOX的抑制率均趋于稳定值（80%¹00%）。Glu/Gly-MRPs对LOX酶促反应的迟滞时间具有延长作用,通过Lineweaver-Burk双倒数法确定Glu/Gly-MRPs对LOX的抑制类型为混合型抑制。      

Determination of glycarbylamide residues in chicken tissues by HPLC with post-column reaction

A newly developed HPLC method for determination of glycarbylamide (GB) in chicken liver was applied to other tissues (muscle, fat and kidney). The recoveries of GB in muscle, fat and kidney were 87.2% (CV 0.5), 91.3% (CV 4.7), 79.7% (CV 1.0), respectively. The detection limit of GB was 0.01 ppm. GB concentrations were determined by this method in tissues (muscle, fat, liver and kidney) from chickens sacrificed 5 days after oral administration of GB mixed in feed at 60 mg/kg of feed for 7 days. GB was not detected in these chicken tissues.     

丝素与一氯均三嗪型活性染料反应性的HPLC研究

用异丙胺、对甲酚和甲醇分别模拟蚕丝丝素上氨基、酚羟基和醇羟基,应用高效液相色谱(HPLC)研究一氯均三嗪型活性染料与蚕丝亲核基团的反应性能。结果表明,一氯均三嗪型活性染料与蚕丝上不同亲核基团的反应性能不同,酚羟基在85℃左右,pH值为8~9的条件下最佳,氨基在95℃,pH值为9左右较好,而醇羟基更适合碱性较强的反应条件。结合亲核基团分布状况及含量可以推断,一氯均三嗪型活性染料适宜在pH值为8~9和85~95℃下对蚕丝染色,在此条件下,一氯均三嗪型活性染料主要与蚕丝上的酚羟基反应,氨基起次要作用,而醇羟基的作用甚微。     

Characterization and quantification of anthocyanins in grape juices obtained from the grapes cultivated in Korea by HPLC/DAD, HPLC/MS, and HPLC/MS/MS

The characterization and quantification of anthocyanins in grape cultivars of Oll-Meoru (Vitis coignetiaexVitis labrusca), Neut-Meoru (Vitis coignetiaexVitis labrusca), Muscal Bailey A. (Vitis labruscana), and Campbell Early (Vitis labruscaxV. vinifera) cultivated in Korea were carried out by partial purification through XAD-7 column chromatography followed by C-18 HPLC/diode array detector (DAD), HPLC/MS, and HPLC/MS/MS analyses. The column oven temperature during the reverse phase C-18 HPLC greatly affected the separation of individual anthocyanins. The result showed that the optimum column oven temperature was 35 degrees C. Sixteen different anthocyanins (11 nonacylated and 5 acylated anthocyanins) were identified in the grape juices. Oll-Meoru, Neut-Meoru, and Muscat Bailey A (MBA) grape juices contained only nonacylated anthocyanins. Oll-Meoru and Neut-Meoru grape juices had same anthocyanins, but their proportions were considerably different. Peonidin 3,5-diglucoside and malvidin 3,5-diglucoside were the major anthocyanins in Oll-Meoru grape juice. Delphinidin 3-glucoside was, however, the major anthocyanin in Neut-Meoru grape juice. Peonidin 3-glucoside and malvidin 3-glucoside were the most abundant anthocyanins in Muscal Bailey A grape juice. Campbell Early grape juice contained both nonacylated and acylated anthocyanins. Cyanidin 3-(p-coumaroyl)glucoside-5-glucoside and peonidin 3-(p-coumaroyl)glucoside-5-glucoside were the most abundant anthocyanins in Campbell Early grape juice. Total anthocyanin contents were greatly different in different grape jucies, with the highest in Neut-Meoru juice (1043.5 microg/mL), followed by Oll-Meoru (997.7 microg/mL), MBA (390.2 microg/mL), and Campbell Early (183.9 microg/mL) juices. The total anthocyanin content in Neut-Meoru grape juice was 5.67 times higher than that in Campbell Early grape juice. This represents the 1st report on the systematic characterization and quantification of anthocyanins in the juices of these grapes cultivated in Korea.     

High correlation of methylglyoxal with acrylamide formation in glucose/asparagine Maillard reaction model

α-Dicarbonyl compounds were highly reactive intermediates formed in Maillard reaction (MR), and o-phenylenediamine (OPD) was widely used as a trapping agent for α-dicarbonyl compounds. Both aqueous glucose/asparagine (Glc/Asn) and glucose/asparagine/o-phenylenediamine (Glc/Asn/OPD) model systems were heated at 150 °C for up to 30 min. The α-dicarbonyl compounds formed in MR were identified by HPLC/MS in our particular model system, indicating that 3-deoxy-2-hexosulose, 2,3-butanedione and methylglyoxal (MG) were three main α-dicarbonyl compounds. In this work, MG was chosen as a representative of α-dicarbonyl compound in MR to investigate the influence on the formation of acrylamide (AA). The concentrations of AA, MG and Asn were detected during MR by HPLC method. The results indicated that the formation of AA increased with the heating time, and nearly 80% of AA formed through participation of α-dicarbonyl compounds. These results were consistent with the changes of amounts of MG. The amounts of formation and consumption of MG increased with heating time, and from 9 min of reaction, the consumed amounts of MG accounted for 73–88% on basis of total amounts of MG formed in MR, suggesting that most of MG take part in the next reaction steps. Meanwhile, the Asn concentration decreased with heating time in both models. The formation of AA and consumption of Asn were highly correlated with MG. Indeed, as MG concentration in MG/Asn model system decreased during heating at 150 °C, the concentration of AA significantly increased. The coefficient of correlation between consumed amounts of MG and the formed amounts of AA is 0.931, again demonstrating that MG does play a role in AA formation.     

不同缫丝干蛹酶解液及其葡萄糖反应物的味感比较

为了对不同酶种缫丝干蛹酶解液与葡萄糖反应物的味感变化进行研究。本文以缫丝干蛹为原料,用不同蛋白酶进行水解,将其水解液及相应的葡萄糖反应物,采用高效液相色谱法和感官评定法进行分析,确定氨基酸含量的消长变化与味感的相关性。结果表明:在不同酶解方法中,Alcalase2.4L蛋白酶和Protamex蛋白酶分别与风味蛋白酶共同作用后,水解液鲜甜味氨基酸含量较高,分别达到48.7%和53.88%,鲜甜感强;酶解液与葡萄糖反应后,鲜甜味氨基酸含量分别为32.7%和26.6%,鲜甜味降低。说明缫丝干蛹酶解液鲜甜味氨基酸参与热反应并导致反应物味感降低。      

Determination of dl-alpha-tocopherol acetate and dl-alpha-tocopherol in foods by HPLC using post-column photochemical reaction

A reliable analytical method for the simultaneous determination of dl-alpha-tocopherol acetate and dl-alpha-tocopherol in foods was established by HPLC using post-column photochemical reaction with UV and fluorescence detection. For low-fat food such as fruit juice and vegetable sauce, the tocopherols were extracted with methanol containing 0.1% ascorbic acid and the extract solution was injected into the HPLC. For fatty foods such as butter and margarine, the tocopherols were extracted with a mixed solvent of acetonitrile-2-propanol (9:1) containing ascorbic acid. The extract was cleaned up using a Sep Pak plus C18 cartridge and the eluent from the cartridge was injected into the HPLC. The peaks corresponding to tocopherols on the chromatogram were confirmed by comparing their UV spectra with those of the standard mixture at lamp-on and lamp-off of the photochemical reactor. The recoveries of tocopherols from low-fat foods (orange juice and barbecue sauce) fortified at levels of 10 and 100 microg/kg each were 88.3 to 105.8% (RSD 0.5 to 6.0%) and those from the fatty foods (peanut butter and margarine) fortified at 100 microg/kg each were 57.1 to 88.3% (RSD 3.0 to 6.4%). The determination limits corresponded to 10 microg/kg of the tocopherols in the low-fat foods and 20 microg/kg in the fatty foods.     

液相色谱-二极管阵列检测器测定大蒜中的蒜氨酸

建立液相色谱-二极管阵列检测器测定大蒜中蒜氨酸的分析方法.鲜蒜在脱氧水介质中,经微波灭酶后,用甲醇-水提取其中的蒜氨酸,以C18柱分离、二极管阵列检测器扫描检测.以保留时间和蒜氨酸的二阶导数光谱图定性,以215 nm波长下蒜氨酸峰面积定量.方法的线性范围为5.0～500.0μg/mL,加标回收率为93.2%～101.1%.     

On the monitoring of carotenogenesis by Blakeslea trispora using HPLC

A rapid, isocratic RP-HPLC method for the determination of the carotenoids produced by Blakeslea trispora is described. The mixture of acetone:acetonitrile, 60:40, v/v, found appropriate for the cellular triacylglycerol analysis, was also successfully used for the separation of lycopene, γ-carotene and β-carotene. The method was validated for β-carotene using an olive oil triacylglycerol fraction devoid of carotenoids. Recovery study (300 mg/kg oil) was 99%. RSDr and RSD_L were satisfactory (<4%). The limit of quantification was found to be 4.56 ng/5 μL and the system was linear in the range 2.0–30.0 ng/μL.     

Identification of isomers of resveratrol dimer and their analogues from wine grapes by HPLC/MS and HPLC/DAD-UV

A facile method based on HPLC/(−)ESI-MSⁿ is established for the analysis of seven isomers of resveratrol dimers and three of their analogues in Xinjiang wine grapes. The structures of these compounds are positively or tentatively determined. Among them, three are tentatively identified as new compounds. MSⁿ experiments on the [M−H]⁻ ions provide abundant structural information, especially regarding the relative abundance of the key product ions, m/z 333 and 369 (385 in compound 3), which can be utilised to distinguish whether or not the compound identified contains the scaffold of the isomer of a resveratrol dimer. The relative abundance of key product ions remains unchanged as collision energy varies from 0.60 to 0.95 V. All the trans-, and cis-isomers could be identified by HPLC/DAD-UV spectra. The UV spectra of compounds 2 and 9 tentatively show cis and trans- configurations, respectively.     

HPLC示差折光分析法测定饮料中果糖、葡萄糖、蔗糖含量

本文利用高效液相示差折光分析法测定饮料中果糖、葡萄糖、蔗糖含量。方法采用Agilent Car-bohydrate柱，流动相为乙腈＋水（75：25），流速0．6mL／min．检测器池温度：35℃，柱温25℃，进样量15μL。方法的检出限0．5％，加标回收率92．0％～110．0％．相对标准偏差为4．13％。该法具有样品预处理简单，灵敏度高，分析时间短等优点，可用于饮料样品的直接测定。     

基于高效液相色谱-串联四极杆飞行时间质谱法的大豆油甘油三酯组成特性分析

采用高效液相色谱-串联四极杆飞行时间质谱法研究大豆油甘油三酯组成特性.对大豆油中16种甘油三酯进行了定性和相对含量测定,分别为LLnLn (0.97％ ～4.72％)、LLLn (9.06％ ～14.22％)、LLL(23.19％ ～ 35.57％)、LOLn(4.64％ ～ 7.44％)、PLLn(2.18％～4.48％)、LLO(15.23％ ～ 22.74％)、PLL (9.73％～16.18％)、LOO(3.49％ ～6.48％)、PLO+SLL(2.90％～9.86％)、PPL(0.81％ ～1.06％)、OOO(1.23％ ～2.90％)、OLS(1.56％～4.82％)、POO (0.30％ ～1.06％)、SSL(0.47％～0.96％)和POS(0.15％ ～0.51％).其中,相对含量较高的依次是LLL、LLO、PLL和LLLn,占大豆油总甘油三酯的57.21％ ～ 88.71％.该分析研究可为大豆油品质鉴定及油脂掺伪鉴别提供理论依据.     

HPLC-MS测定白酒中氨基甲酸酯类农药残留

建立了一种同时对白酒中10种氨基甲酸酯类农药残留的HPLC-MS测定方法。色谱条件:色谱柱Phenomenex-LunaCN100A(250mm×4.6mm×5μm),流动相乙腈-水(在40min内乙腈由20%变为80%),流速1.00mL/min,检测波长195nm,柱温25℃,进样量20μL。质谱条件:电喷雾离子源(ESI+源),扫描范围(m/z)为50～350,干燥气温度350℃,干燥气流速8.0mL/min,雾化气压力275.86kPa。样品制备:白酒样品用固相萃取处理后,氮吹浓缩,乙腈定容至2mL。结果表明,10种氨基甲酸酯类农药残留在0.05～3μg范围积线性关系良好,相关系数R2>0.99。平均回收率在72.6%和97.6%,RSD在2.6%～5.9%之间。结论:方法灵敏度高、操作简便、结果准确,可用于酒样中痕量农药残留的含量测定。