| 摘要: |
| 【目的】探明枇杷叶次生代谢物在生长过程中的变化规律，为枇杷叶的有效利用提供理论依据。【方法】以枇杷夏梢为试验材料，从新叶停止伸长生长(7月4日)开始，每3个月采样1次，以甲醇作为提取溶剂，采用超高效液相色谱 质谱法（UHPLC-MS），测定枇杷叶中的酚酸类、有机酸类、单宁类、黄酮类、萜类、生物碱类、香豆素类等次生代谢成分，分析其在不同时期的变化规律。【结果】在枇杷叶甲醇提取物中共分离鉴定出8类71种化合物，包括酚酸类8种，有机酸类5种，单宁类3种，黄酮类28种，萜类18种，生物碱类2种，香豆素类3种，其他类4种。酚酸类主要成分为绿原酸和新绿原酸，黄酮类主要成分为儿茶素和2″-O-对香豆酰基牡荆素，萜类主要成分为积雪草酸、山楂酸和皂皮酸。在枇杷夏梢周年生长中，各类次生代谢物质的化合物数量和总含量呈现出规律变化：从化合物数量看，除单宁类、生物碱类和其他类次生代谢物数量基本不变外，其余5类次生代谢物的化合物数量均呈增加趋势，而且化合物数量增加都在生长初期的6个月内完成；从每类物质总含量看，萜类和其他类物质含量呈逐渐上升趋势，酚酸、黄酮和香豆素3类物质含量呈先上升后下降趋势，单宁类物质含量变化不大，有机酸类与生物碱类物质含量总体呈下降趋势。【结论】以萜类为利用目标原料时，应在枇杷叶老熟并即将掉落时采集；而以酚酸、黄酮类物质为利用目标原料时，应在1月份采集。 |
| 关键词: 枇杷叶 超高效液相色谱 质谱法 次生代谢物 |
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| 基金项目:财政部“以大学为依托的农业科技推广模式建设”项目（XTG2021-23） |
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| Annual variation of secondary metabolites in loquat leaves based on UHPLC-MS technology |
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WANG Zengbin,SONG Xue,WANG Yang,et al
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| Abstract: |
| 【Objective】This study explored variations of secondary metabolites of loquat leaves during growth process to provide theoretical basis for effective utilization of loquat leaves.【Method】Summer shoots of loquat were collected once every three months since elongation of new leaves ended on July 4.With methanol as extraction solvent,UHPLC-MS was used to determine secondary metabolites of phenolic acids,organic acids,tannins,flavonoids,terpenoids,alkaloids and coumarins,and their changes in different stages were analyzed.【Result】A total of 71 compounds in 8 categories were isolated and identified from methanol extract of loquat leaves,including 8 phenolic acids,5 organic acids,3 tannins,28 flavonoids,18 terpenoids,2 alkaloids,3 coumarins and 4 other compounds.Main phenolic acids were chlorogenic acid and neochlorogenic acid,main flavonoids were catechin and vitexin 2″-O-p-coumarate,while main terpenoids were asiatic acid,maslinic acid and quillaic acid.In annual growth of loquat summer shoots,number and total contents of all secondary metabolites showed regular changes.In terms of compounds number,secondary metabolites exhibited an increasing trend during the annual growth of loquat leaves,and the growth completed within the first 6 months of growth,except for tannins,alkaloids and other secondary metabolites.In terms of total content,terpenoids and other compounds accumulated gradually during growth,phenolic acids,flavonoids and coumarins increased firstly and then decreased,tannins changed insignificantly during growth,while organic acids and alkaloids showed a decreasing trend overall.【Conclusion】Samples should be collected when loquat leaves were ripe to drop to utilize terpenoids,while samples should be collected in January to utilize phenolic acids and flavonoids. |
| Key words: loquat leaves UHPLC-MS secondary metabolites |
