罗布麻苷提取和检测条件优化及其年限累积效应分析

Optimization of Cymarin Extraction and Detection Conditions and Analysis of Its Cumulative Effects over Multiple Years

为优化罗布麻中罗布麻苷的提取和检测条件,明确种植年限对罗布麻苷累积的影响,本试验利用超声波法提取罗布麻苷,用3,5-二硝基苯甲酸-氢氧化钠显色法测定其含量,用铁离子还原/抗氧化能力法(FRAP)和1,1-二苯基-2-三硝基苯肼(DPPH)法检测其抗氧化能力。结果表明:罗布麻苷标准品显色反应液在540 nm下的吸光度与其含量呈良好的线性关系,线性范围为0~1.0 mg/mL(R^(2)=0.992),样品回收率为99.218%,相对标准偏差(RSD)为1.909%。在考察范围内,对提取试剂乙醇浓度、超声时间和料液比进行分析发现,待测样品与95%乙醇的料液比为1∶10(g/mL)、超声提取30 min时,罗布麻苷含量最高,达到639.34μg/g。种植3、7、10年的罗布麻不同部位罗布麻苷含量差异显著,依次为7年叶>3年叶>10年叶>3年茎>7年根>10年根>3年茎>7年根>10年茎。年限间比较,种植7年的罗布麻具有较高的罗布麻苷含量,为626.25μg/g,抗氧化能力表现为7年>3年>10年,且3个种植年限间均有较强的DPPH自由基清除能力。相关性分析表明,种植7年的罗布麻中罗布麻苷含量与抗氧化能力呈正相关。本研究结论可为罗布麻苷提取及相关功能性产品开发提供依据。

To optimize the extraction and detection conditions of cymarin in Apocynum venetum L.(AV)and clarify the influence of planting years on its cumulative effect,ultrasonic extraction was used to extract cy-marin,and its content was determined by the 3,5-dinitrobenzoic acid-sodium hydroxide colorimetric method.Its antioxidant capacity was detected by ferric reducing/antioxidant power(FRAP)and 1,1-diphenyl-2-trini-trophenylhydrazine(DPPH)methods.The results showed that the absorbance of cymarin standard solution at 540 nm had a good linear relationship with its concentration in the range of 0~1.0 mg/mL(R^(2)=0.992)with sample recovery rate as 99.218%and relative standard deviation(RSD)as 1.909%.Within the investigating range,the analysis results of ethanol concentration,ultrasonic time and liquid-to-solid ratio showed that the highest cymarin content of 639.34μg/g could be obtained when using 95%ethanol as extraction reagent,the ratio of sample to extraction reagent as 1∶10 g/mL,and ultrasonic extraction for 30 minutes.The distribution of cymarin content in different parts of AV was significantly different among different planting years(3,7 and 10 years),which were sequenced in the order of 7-year leaves>3-year leaves>10-year leaves>3-year stems>7-year roots>10-year roots>3-year stems>7-year roots>10-year stems.Comparing between planting years,the AV with 7 planting years had higher cymarin content as 626.25μg/g;the antioxidant capacity showed 7 years>3 years>10 years,and stronger DPPH free radical scavenging ability was found among the three kinds of planting years.Correlation analysis showed that the cymarin content of 7-year AV was positively correlated with the antioxidant capacity.These results could provide bases for cymarin extraction and related functional product development.