UHPLC-DAD-ESI-MS/MS法分析紫山药块根和茎叶中酚类物质

Identification of Phenolic Components in the Root and Leaf of Purple Yam (Dioscorea alata) by UHPLC-DAD-ESI-MS/MS

摘要:

本文采用微波辅助法，以80%甲醇作为溶剂提取经冻干后紫山药块根和地上茎叶中的多酚类物质，提取物经超高效液相色谱分离、电喷雾串联三重四级杆质谱正和负离子方式检测分析。根据液相保留时间、紫外吸收、相对分子质量和二级碎片离子等信息，结果表明，紫山药块根和茎叶中酚类物质主要为酚酸、花色苷及黄酮类化合物。分析得到的29种酚类化合物中，5-O-咖啡酰奎宁酸、阿魏酰奎宁酸（tR：12.289）、迷迭香酸、芦丁和槲皮素为块根和茎叶共有组分，块根中另含有芥子酸、芥子酸葡萄糖苷、丁香酸衍生物、香豆酸衍生物、阿魏酸衍生物、芥子酸二葡萄糖苷和花色苷等11种酚类物质。茎叶中除5种共有组分，还含有咖啡酸、咖啡酰奎宁酸甲酯、咖啡酰莽草酸、对香豆酰奎宁酸、香豆酰奎宁酸甲酯、山奈酚-3-O-芦丁糖苷与迷迭香酸甲酯等13种酚类化合物。

Abstract:

Total polyphenols were obtained from the freeze-dried root and leaf of Dioscorea alata by microwave-assisted extraction using 80% methanol as the extraction solvent. The extract was analyzed by ultra-high-performance liquid chromatography with diode array detector coupled with electrospray ionization-tandem mass spectrometry (UHPLC-DAD-ESI-MS/MS) in the positive/negative ion mode. Based on the retention time, ultraviolet absorption, relative molecular weight, and MS2 fragmentation pattern in LC-MS chromatography, the main phenols in the root and leaf of Dioscorea alata were phenolic acids, anthocyanins, and flavonoids. Twenty-nine phenolic compounds were identified in the purple yam, and 5-O-caffeoylquinic acid, feruloylquinic acid (tR: 12.289), rosmarinic acid, rutin, and quercetin were the common components in both root and leaf. Eleven further phenolic compounds were identified from the root of purple yam, including sinapic acid, sinapic acid-glucosides, syringic acid derivatives, coumaric acid derivatives, ferulic acid derivatives, sinapic acid-diglucoside, and anthocyanins. Furthermore,13 phenolic compounds were found in the leaf of purple yam, including caffeic acid, caffeoylquinic acid methyl ester, caffeoyl shikimic acid, p-coumaroylquinic acid, coumaroylquinic acid methyl ester, kaempferol -3-O-rutinoside, and rosmarinic acid methyl ester.