A Sensitive Reversed-Phase High-Performance Liquid Chromatography Method for the Quantitative Determination of Milk Xanthine Oxidase Activity

A new reversed-phase high performance liquid chromatography method was developed to quantitate the activity of xanthine oxidase involved in milk fat globule membrane with xanthine as the substrate and the separation of product (uric acid). The increment of uric acid in the reaction system was used to calculate the total activity of XO. The optimized assay conditions, linearity of detection, recovery of uric acid and chromatogram were developed in text, indicating this method is simple, rapid and efficient. It is an alternative potential method for the determination of the activity of XO in milk.

PHENOLIC ANTIOXIDANTS DETERMINATION IN FOOD ITEMS USING REVERSED-PHASE HPLC

The determination of synthetic phenolic antioxidants （SPAs） including propyl gallate （PG）, tertiary butyl hydroquinone （TI3HQ）, butylated hydroxyanisole （BHA） and butylated hydroxytoluene （BHT） in food items is reported using high performance liquid chromatography （HPLC）. A Cls column is used as the stationary phase, acetonltrile and water：Acetic acid （1%） is used as the mobile phase of gradient elution and the UV detec- tor is set at 280 nm. Under the above conditions, four antioxidents is completely separated within 8 rain. The limit of detection, linear range, and reproducibility of HPLC are evaluated. Isolation parameters of SPAs from different types of food items （cooking oil, margarine and butter, and cheese） are optimized. SPAs are extracted from food items through extraction with methanol/acetonitrile （1 ： 1, in volume）, vortex, ultrasonic treatment and precipitation in a freezer （2 h）. For cooking oil margarine, butter and cheese at 50 and 200 rag/L, recoveries of SPAs are 93.3%0--108.3% （PG）, 85.3~^--108.3~~ （TBHQ）, 96.7~^--101.2~/6 （BHA）, and 73.9^-- 94.6% （BHT）. The method is applied to the determination of SPAs in 38 food items （16 cooking oils, 8 mar- garine, 6 butter and 6 cheese samples）. The levels of SPAs in positive samples are all below the legal limits of China.

Determination of synthetic phenolic antioxidants in essence perfume by high performance liquid chromatography with vortex-assisted,cloud-point extraction using AEO-9

This study aimed to establish a rapid analytical method to determine antioxidants in essence. A simple,efficient and practical, vortex-assisted, cloud-point extraction（VACPE） procedure is proposed for extracting and pre-concentrating four different of synthetic phenolic antioxidants（SPAs）, propyl gallate（PG）, tert-butylhydroquinone（TBHQ）, butylated hydroxyanisole（BHA）, butylated hydroxytoluene（BHT） in essence prior to high performance liquid chromatography（HPLC） analysis. The non-ionic surfactant, fatty alcohol polyoxyethylene ether-9（AEO-9）, was used as extractant and vortex-mixing was utilized to reduce extraction time and improve extraction efficiency. The effective parameters of the extraction process, such as volume of extraction solvent, pH, vortex-mixing time, equilibration temperature and time, were optimized. Under the optimum conditions, the linear range of PG, TBHQ,BHA and BHT was 8.0–800 ng/mL. All correlation coefficients of the calibration curves were higher than0.996 and relative standard deviations（RSD, n = 5） were 2.36%–5.46%. The proposed method was successfully applied to the extraction and determination of antioxidants in essence samples with satisfactory relative recoveries of 89.4%–103.5%. The results confirmed the SPAs of essence could be effectively monitored by this method and also established good reference criteria for essence.

A highly sensitive SPE-liquid/liquid extraction-RPLC analytical method for the determination of 6β-hydroxycortisol and cortisol in cancer patients' urine

A highly sensitive SPE-liquid/liquid extraction RPLC method has been developed for the analysis of 6β-hydroxycortisol and cortisol in the urine of cancer patients. Methods： After SPE column purification and liquid-liquid extraction, the sample test solutions were analyzed with RPLC using a C18 analytical column. This improved analytical method has been validated for linearity, accuracy （recovery from urine）, repeatability （within-day and between-day precision）, specificity, sensitivity, and stability. This SPE-liquid/liquid extraction-RPLC is rapid, simple, accurate and reproducible. The technique is particularly useful for monitoring the CYP3A activity of cancer patients in clinical settings. The results are expressed as the ratio of 6β-hydroxycortisol to cortisol. Results： The CYP3A activity from a total of 153 samples was measured using this improved method. Considerable variation in the CYP3A activity of different cancer patients has been documented. Thus, personalized medical treatment based on the individual metabolic enzyme activity level is necessary. Conclusion： This new analytical method facilitates such individualized medical treatments.

A systematic study on mycochemical profiles, antioxidant, and anti-inflammatory activities of 30 varieties of Jew’s ear(Auricularia auricula-judae)

The health-promoting properties and chemical profiles of 30 Jew’s ear mushroom varieties were investigated. The antioxidant properties were determined by ferric reducing antioxidant power(FRAP), 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging, 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) free radical scavenging, and metal chelating ability(MCA) assays, while phenolic profiles were determined by total phenol content(TPC) and total flavonoid content(TFC) colorimetric assays. Total carbohydrate, β-glucan, and melanin contents were determined by colorimetric methods. 5’-Nucleotides, vitamin D_(2), ergosterol, and ergothioneine contents were determined by high performance liquid chromatography(HPLC). Anti-inflammation activities of Jew’s ear were evaluated by the colorimetric protease inhibitory method. The results showed that Jew’s ear mushrooms possessed substantial phenolics and antioxidant properties. All the Jew’s ear varieties contain high amount of total carbohydrate, β-glucan, reducing sugar, melanin, pectin, vitamin D2, ergosterol, and ergothioneine. The current findings could provide scientific information for breeders to nurture desired varieties and for food industry to develop new health promoting products.

Quantification of phenolic compounds and antioxidant capacity of an underutilized Indian fruit:Rayan[Manilkara hexandra(Roxb.)Dubard]

The fruit of Manilkara hexandra(Roxb.)Dubard is one of the most underutilized fruits of India and in Gujarat state.It is popularly known as‘Rayan’.The fruit and seed of Rayan were analysed for their total phenolic and flavonoid content,phenolic compounds and total antioxidant capacity with six different assay methods.The results indicated that the methanolic extract of Rayan fruit being a good source of phenolic(811.3 mg GAE/100 g fw)and flavonoid(485.56 mg RE/100 g fw)content.Also,eleven known phenolic compounds were tentatively identified for the first time from the fruit and seed of Rayan.The LC–MS/MS analysis of fruit revealed the presence of major phenolic compounds such as gallic acid,quercetin and kaempferol,while quercetin,gallic acid and vanillic acid in seed.The presence of quercetin suggests health benefits.The fruit of Rayan was also proved to be a better source of antioxidants as measured by FRAP,RPA,DPPHRSA,ABTSRSA and HRSA except NORSA in comparison with that of seed.The current study explains that M.hexandra is a relatively good source of antioxidants such as phenols and flavonoids for diet.

Antioxidant compounds and capacities of Gac (Momordica cochinchinensis Spreng) fruits

Objective: To identify and determine the composition of antioxidant compounds, and to evaluate the antioxidant abilities of Gac fruit parts(peel, pulp, seed and aril) grown in Malaysia. Methods: LC-MS/MS was used for identification of antioxidant compounds and UV-Vis for estimation of the contents of phenolics, flavonoids, and carotenoids. Lycopene and β-carotene were quantified using high-performance liquid chromatography. DPPH(2, 2-diphenyl-1-picrylhydrazyl) and ferric reducing antioxidant power assays were employed to evaluate antioxidant capacities. Results: Phytochemicals were found amongst all the fruit parts. Notably, significant amounts of carotenoids [(107.4 ± 4.5),(85.7 ± 4.4),(110.6 ± 2.1) mg/100 g dry weight(DW)], and relatively high levels of both phenolics [(27.3 ± 1.7),(28.9 ± 2.4),(30.8 ± 2.7) mg/100 g DW] and flavonoids [(38.1 ± 2.2),(8.8 ± 1.3),(24.5 ± 3.3) mg/100 g DW] were found in the fruit's peel, pulp and aril, respectively. Seed part also showed a relatively high level of flavonoids [(18.1 ± 2.3) mg/100 g DW]. Lycopene and β-carotene were found to be significantly high(P < 0.05) in aril [(579.3 ± 22.7) and(621.0 ± 35.0) μg/g DW], followed by peel [(51.0 ± 7.5) and(210.0 ± 12.5) μg/g DW] and pulp [(37.6 ± 10.9) and(205.6 ± 22.1) μg/g DW)]. Antioxidant assays revealed that aril possessed the highest scavenging activity(IC_(50) = 865 μg/mL), while the peel possessed the highest ferric reducing power of 140 μmol FeSO4/μg. Conclusions: The current results demonstrate that Gac fruit grown in Malaysia is a rich source of phytochemicals, especially carotenoids, and possesses antioxidant activities. Thus, such findings suggest Gac fruit as a source of an antioxidant plant.

Phenolic Antioxidants in Cypriot Wines as a Tool for Their Varietal Discrimination： Preliminary Results

A total of 56 wines from different vintages and wine-growing regions of Cyprus were used to analyze six biologically interesting phenolic antioxidants （gallic acid, catechin, vanillic acid, epicatechin, coumaric and feroulic acid） by high performance liquid chromatography. The study includes red and white Cypriot authentic wines from local and imported varieties that were produced under the same vinification conditions at a Model Winery. Results extracted after the chemometric analysis of the measured concentrations show a strong relationship of the phenolic antioxidative capacity with the variety of the wines and gallic acid followed by vanillic acid found in the highest concentrations of the other antioxidants studied. Comparing the concentrations found with bibliographic data for wines from other countries, it was found that, the concentration levels of vanillic and ferulic acid were significantly higher for Cypriot wines.

淡竹叶多酚的提取纯化工艺优化、组分分析及体外抗氧化活性研究

目的确定淡竹叶多酚提取纯化工艺,分析主要成分及体外抗氧化活性。方法采用超声辅助提取淡竹叶多酚,通过响应面实验确定最佳提取条件。选取适合淡竹叶多酚纯化的大孔树脂,对纯化工艺参数进行优化。通过高效液相色谱-质谱法(high performance liquid chromatography-mass spectrometry,HPLC-MS)鉴定淡竹叶多酚的主要成分,并评价其体外抗氧化活性。结果淡竹叶多酚的最佳提取工艺参数为:乙醇体积分数60%、超声功率500 W、料液比1:25(g/mL)、超声时间24 min及超声温度59℃,该条件下淡竹叶多酚提取量为8.01 mg/g。淡竹叶多酚纯化工艺参数为:上样质量浓度6 mg/mL、pH 4、流速2 mL/min、解吸液为70%乙醇、解吸体积90 mL,纯化后的淡竹叶多酚纯度由12.86%提高到76.18%。通过HPLC-MS鉴定出16种酚类成分,且纯化后多酚有较高的抗氧化活性。结论本研究得到了淡竹叶多酚提取纯化工艺,得到的多酚纯化物有明显的抗氧化活性。

山栀子不同部位活性成分含量及抗氧化活性

为比较山栀子不同部位活性成分并评价各部位体外抗氧化活性,本文用超声辅助提取法提取山栀子不同部位有效成分,并测定得率;使用紫外-可见分光光度法测定总环烯醚萜、总藏红花素、总黄酮和总酚含量;利用高效液相色谱法测定山栀子不同部位活性成分单体;采用DPPH、ABTS+自由基清除试验评估其体外抗氧化能力,并进行活性成分与抗氧化活性的相关性分析。结果表明,山栀子叶中的总环烯醚萜和总酚含量最高,分别为244.87±5.89 mg·g^(-1)和16.71±0.55 mg·g^(-1);山栀子果中的总藏红花素(16.18±1.40 mg·g^(-1))相较于其余部分存在显著性差异(P<0.05),其中藏红花素-Ⅰ为藏红花苷主要形式,约占总藏红花素的60%;山栀子花中的总黄酮含量最高43.61±1.01 mg·g^(-1)。根据DPPH自由基、ABTS+自由基清除率试验,山栀子叶的抗氧化活性最好,IC50分别为36.00±2.70和31.96±3.87μg·mL-1;经相关性分析发现环烯醚萜类化合物与酚类化合物与抗氧化能力呈强相关性。采用超声辅助提取法提取得到的山栀子不同部位活性成分,发现不同部位均具有一定抗氧化能力,同时叶具有超越果的抗氧化活性,为天然抗氧化剂的开发提供了理论来源。

花生红衣中反式白藜芦醇对HEK293T细胞抗氧化的影响

目的:分析花生红衣中的白藜芦醇成分,探究其主要成分反式白藜芦醇(RES)对人胚胎肾细胞293(HEK293T)抗氧化的影响及其潜在的分子机制。方法:采用超声波辅助酶法提取花生红衣中的白藜芦醇,采用高效液相色谱-质谱联用(HPLC-MS)技术分析花生红衣中白藜芦醇粗提液的组成成分。通过测定细胞活力,检测RES对HEK293T细胞的最高毒性。通过荧光素酶报告基因试验及免疫印迹试验检测其对Keap1-Nrf2-ARE抗氧化信号通路的影响,以DPPH自由基清除率评价其体外抗氧化能力。结果:HPLC-MS结果表明,花生红衣中含有白藜芦醇苷、白皮杉醇和RES。由于白藜芦醇在自然界中主要以反式白藜芦醇形式存在,因此选择RES进行后续试验。细胞存活力检测结果表明,RES对HEK293T细胞的最高无毒浓度为50μmol/L,体外抗氧化作用呈浓度依赖性。荧光素酶报告基因分析表明,RES显著诱导了ARE介导的转录激活。免疫印迹结果显示,RES能诱导Nrf2介导的3个抗氧化蛋白表达【血红素氧合酶1(HO-1)、醌氧化还原酶1(NQO1)和谷氨酸半胱氨酸连接酶(GCLM)】表达。此外,DPPH自由基清除率测定结果表明,RES能有效清除DPPH自由基,具有体外抗氧化能力。结论:花生红衣中白藜芦醇的主要成分RES对HEK293T细胞有抗氧化作用,可通过Keap1-Nrf2-ARE信号通路激活潜在的抗氧化活性。

通过式固相萃取-高效液相色谱法测定糕点中15种抗氧化成分

目的建立通过式固相萃取-高效液相色谱法同时测定糕点中7种天然抗氧化成分和8种合成抗氧化剂的定量分析方法。方法目标物采用1%乙酸乙腈溶液提取,用通过式亲水亲油平衡(hydrophilic and oleophilic balance,HLB)固相萃取柱净化,净化液浓缩处理后供高效液相色谱仪分析,15种目标物以0.5%甲酸溶液-甲醇为流动相梯度洗脱,C18色谱柱分离,二极管阵列检测器280 nm处测定。结果15种抗氧化成分在1~50μg/mL范围内有良好的线性关系,表没食子酸儿茶素的检出限(limit of detection,LOD)为2 mg/kg,定量限(limit of quantification,LOQ)为5 mg/kg,其余14种化合物的LOD为0.2 mg/kg,LOQ为0.5 mg/kg;各组分的平均回收率为88.10%~94.73%,相对标准偏差(relative standard deviations,RSDs)≤5.2%。结论本方法具有快速简单、高灵敏度、重现性好等优点,对糕点中抗氧化剂含量的检测具有很好的实用价值,同时为糕点的质量安全提供了有效的技术支持。

基于HPLC-ECD测定鱼腥草叶多酚含量及抗氧化活性

目的:建立高效液相色谱-电化学检测法(High performance liquid chromatography-electrochemical detection,HPLC-ECD)测定鱼腥草叶中多酚类化合物,并采用相关性分析方法明确不同多酚单体化合物对于抗氧化活性的贡献。方法:鱼腥草叶经80%(v/v)甲醇超声提取,基于建立的HPLC-ECD检测方法测定12种多酚化合物含量。采用福林酚法测定鱼腥草叶总酚含量,以自由基清除能力和铁离子还原能力进行抗氧化活性评价,采用聚类热图和灰色关联分析法进行多元统计分析。结果:建立的HPLC-ECD方法线性、精密度、重复性、稳定性均良好,平均加样回收率为93.25%~103.97%,RSD为1.99%~4.47%。不同来源的鱼腥草叶的总酚含量为5.98~52.86 mg GAE/g,其含量与ABTS+、DPPH自由基清除能力和铁离子还原能力显著性相关(P<0.05)。鱼腥草中含量较高的多酚类化合物为咖啡酸和槲皮素的衍生物,12种酚类化合物均与抗氧化活性有较高的关联度,其中异槲皮苷、槲皮苷、异绿原酸A、金丝桃苷、芦丁的相关性最高。本研究明确了鱼腥草叶抗氧化的主要活性成分,可以为鱼腥草质量评价和资源开发提供参考。

继代培养对冬虫夏草菌品质及抗氧化活性的影响

为探究继代培养对冬虫夏草菌品质及抗氧化活性的影响,对冬虫夏草CS17菌株进行继代培养,并测定其在不同继代培养过程中菌丝生物量、核苷类物质组成及含量、抗氧化活性的变化差异。结果表明:冬虫夏草CS17菌株连续培养6代所得菌丝生物量为0.47~0.79 g,在第3代积累量最高,为0.79 g;冬虫夏草CS17菌株连续培养6代所得菌丝体中腺苷、肌苷、鸟苷、胞苷、尿苷总含量为1.005~6.516 mg/g,在第2代样品积累量最高,为6.516 mg/g。不同继代培养代数培养过程中,冬虫夏草菌丝体DPPH自由基、ABTS+自由基清除能力及总还原力均表现为先上升后下降趋势,第2代样品DPPH自由基、ABTS+自由基清除能力及总还原力最强,第3代至第6代逐渐降低。冬虫夏草CS17菌株连续培养6代所得菌丝体中,菌丝生物量在第3代达到最高,5种核苷类总含量在第2代样品中积累量最高,抗氧化活性在第2代样品中表现较好。

基于不同极性部位指纹图谱及理化性质对明矾加工栀子的质量评价研究

目的建立栀子不同极性部位HPLC指纹图谱,系统研究栀子化学成分分布情况,并以此为基础结合色价及抗氧化活性实验,探究明矾水煮炮制栀子的合理性与必要性,为全面评价栀子质量及合理临床用药提供参考.方法采用水浴加热回流法提取样品,分别采集明矾水煮栀子和水煮栀子不同极性部位的HPLC指纹图谱,检测不同炮制方法栀子色价及其抗氧化活性,运用聚类分析、主成分分析等多种化学计量学方法进行综合比对研究.结果石油醚部位共标定11个共有峰,氯仿部位共标定9个共有峰,乙酸乙酯部位共标定9个共有峰,正丁醇部位共标定17个共有峰.明矾水煮栀子色价明显高于直接水煮,但抗氧化活性无明显差异,综合化学计量学分析结果,明矾水煮与直接水煮栀子各极性部位的化学成分差异均较小.结论明矾处理栀子主要在大工业生产中起固色及增加色泽的作用,对栀子饮片药用质量无明显影响,可以考虑用水煮处理方法直接替代明矾水煮处理,以减少潜在的明矾中毒风险,增加药物使用的安全性;本研究作者所建立的不同极性部位HPLC指纹图谱色谱信息丰富,峰型和分离度均较好,可以全面反映栀子化学成分分布,为栀子的整体质量评价提供参考.

灯笼果叶片、宿萼和果实化学成分分析及抗氧化活性评价

为全面评估分析酸浆属(Physalis)国内栽培最广的灯笼果(Physalis peruviana L.)化学成分及抗氧化活性,该研究采用紫外分光光度法测定了灯笼果叶片、宿萼和果实提取物总酚、总黄酮含量,应用超高效液相色谱质谱联用技术鉴定其化合物,并检测主要化合物含量,分别应用DPPH自由基、ABTS阳离子自由基、羟自由基清除和铁离子还原法测试提取物体外抗氧化活性。结果表明,灯笼果叶片提取物总酚(8.15 mg GAE/g DW)和总黄酮(30.43 mg RT/g DW)含量最高,宿萼提取物次之,果实提取物总含量最低。从3个部位中共鉴定4种黄酮、3种脂肪酸、1种醉茄内酯、1种二苯并呋喃类和1种羟基肉桂酸类化合物。叶片和宿萼提取物化合物种类丰富,其中叶片提取物紫云英苷(492.03μg/g DW)含量最高,宿萼提取物金丝桃苷(162.10μg/g DW)含量最高,果实提取物仅检测到阿魏酸-4′-O-葡萄糖苷化合物(137.37μg/g DW)。叶片提取物有良好的清除羟自由基能力(SC_(50)=0.61 mg/mL),宿萼提取物清除DPPH自由基(SC_(50)=0.19 mg/mL)、ABTS阳离子自由基能力(0.13 mmol TE/g)和铁离子还原能力(0.16 mmol Fe^(2+)/g)最优。研究结果丰富了灯笼果次级代谢产物数据,为充分利用灯笼果资源、开发天然抗氧化产品提供了科学依据。

食品接触用橡胶中防老剂6PPD检测方法建立及适用性

建立食品接触用橡胶制品中防老剂6PPD的色谱和光谱分析方法,并明晰各方法的实用性。以食品接触用橡胶奶管为研究对象,采用恒温超声萃取和模拟实际工况的迁移实验,预处理橡胶制品获取含6PPD样品溶液;通过氢火焰离子化检测器辅助气相色谱法、二极管阵列检测器辅助高效液相色谱法、紫外分光光度法协同分析样品溶液中的6PPD。与GB/T 33078-2016相比(保留时间10.50 min),气相色谱法和液相色谱法的保留时间缩短至7.58 min和2.15 min;此外,它们具有较高的灵敏度(定量限:8.7μg·L^(-1),20.0μg·L^(-1))和选择性,可以分析复杂基质中的超痕量6PPD。紫外可见分光光度法不具备分离功能且定量限高(270.6μg·L^(-1)),适合橡胶样品的较高初始含量的6PPD测定。本研究成功建立了分析橡胶制品中6PPD的三种分析方法,比较分析了各自的优缺点及适用范围,为进一步研究环境或食物链中6PPD的风险评估提供强有力的技术支持。

不同采收期疏花蔷薇果成分积累及抗氧化活性研究

研究不同采收期疏花蔷薇果(Fructus Rosae Laxae,FRL)中主要化学成分的积累量与其体外抗氧化活性的相关性,确定其最佳采收期。采用高效液相色谱法(HPLC)测定不同采收期FRL中5种主要成分的含量,并考察其体外抗氧化活性,通过聚类分析、相关性分析和主成分分析对数据进行统计分析。结果表明:不同采收期FRL中椴树苷、紫云英苷、异槲皮苷、鞣花酸、没食子酸的质量分数范围依次为51.54〜854.10μg/g、11.39〜255.67μg/g、0.23〜1.18 mg/g、0.08〜5.53 mg/g和3.13〜8.29 mg/g,其均具有较好的抗氧化作用。相关性分析显示,紫云英苷、异槲皮苷、没食子酸和鞣花酸的含量与清除DPPH自由基和还原Fe^(3+)活性显著相关(P<0.05);主成分分析结果表明,不同采收期FRL的综合评分为S2>S1>S3>S4>S5>S6>S7;聚类分析结果与主成分分析结果一致,其最佳采收期为7月中旬。

露水草中β-蜕皮甾酮提取工艺优化及其体外抗氧化能力研究

为探究露水草β-蜕皮甾酮的最佳提取工艺,分别考察提取方式和提取温度对β-蜕皮甾酮含量的影响;使用高效液相色谱法检测含量,利用DPPH和ABTS方法评价最佳提取工艺得到β-蜕皮甾酮的抗氧化能力。使用温浸提取和加热回流两种提取方式,分别考察了60、80、100℃下溶剂为水的提取物中β-蜕皮甾酮的含量;选择最佳提取工艺进行提取,进行方法学考察;利用DPPH和ABTS体外自由基清除实验测定其抗氧化活性。结果表明,以水为溶剂,100℃加热回流的提取方式得到的β-蜕皮甾酮的含量最高;在该液相条件下,露水草样品可快速检出并且峰型良好,分离度高。通过自由基清除实验表明其具有体外抗氧化能力并呈一定浓度依赖型。

竹叶提取物中7种黄酮成分含量测定及抗氧化分析

为研究不同竹叶提取物中黄酮成分含量及其与抗氧化活性之间的关系,以2种市售竹叶提取物以及以毛竹等7种竹种的竹叶为材料制备的竹叶提取物共9个样品为研究对象,建立了同时测定竹叶提取物中7种黄酮成分(荭草苷、异荭草苷、牡荆苷、异牡荆苷、苜蓿素、木犀草素和木犀草苷)的高效液相色谱(HPLC)方法,采用SymmetryShield TM RP8色谱柱(250 mm×4.6 mm,5μm),以乙腈为流动相A,0.5%(v/v)乙酸水溶液为流动相B进行梯度洗脱。采用1,1-二苯基-2-三硝基苯肼(DPPH)和羟基自由基清除试验评价竹叶提取物的抗氧化活性,以半抑制浓度(IC_(50))为评价指标,以抗氧化剂2,6-二叔丁基对甲酚(BHT)和叔丁基对苯二酚(TBHQ)为阳性对照,并利用Person相关性分析各黄酮成分含量与抗氧化的关系。结果表明:建立的HPLC测定方法准确可靠,适用于竹叶提取物中黄酮含量的测定。竹叶提取物中7种黄酮含量在14.97~183.94 mg/g范围内,毛竹中7种黄酮总含量最高,为183.94 mg/g。不同竹种间7种黄酮成分的含量存在显著差异,荭草苷、异荭草苷和牡荆苷含量均在毛竹中最高,分别为38.45、101.30和9.42 mg/g。竹叶提取物清除DPPH自由基的IC_(50)值在78.23~179.41 mg/L范围内,清除羟基自由基的IC_(50)值在203.48~1250.81 mg/L范围内。毛竹叶提取物清除DPPH和羟基自由基的IC_(50)值分别为78.23 mg/L和203.48 mg/L,其抗氧化活性最强,具有开发应用价值。相关性分析结果表明,荭草苷、异荭草苷含量与竹叶提取物抗氧化活性密切相关。