HPLC同时测定猫豆中左旋多巴及其衍生物含量

Simultaneous Determination of L-dopa and Its Derivates in Seeds of Mucuna Pruriens Var. Utilis by HPLC

关键词:  猫豆  左旋多巴  四氢异喹啉  高效液相色谱法

Key words:  Mucuna pruriens var. utilis  L-dopa  tetrahydroisoquinoline  HPLC

摘要:

目的 建立同时测定猫豆中左旋多巴(2)及其3种衍生物含量的高效液相色谱法。方法 从猫豆中分离获得3-羧基-6,7-二羟基-1,2,3,4-四氢异喹啉(1)、1-甲基-3-羧基-6,7-二羟基-1,2,3,4-四氢异喹啉(3)、1,1二甲基-3-羧基-6,7-二羟基-1,2,3,4-四氢异喹啉(4)等3种成分；含量测定采用Cosmosil C₁₈-PAQ色谱柱(4.6 mm×250 mm，5 mm)，流动相1%乙酸等度洗脱，流速0.5 mL·min^-1，柱温30 ℃，检测波长280 nm。结果 左旋多巴(2)和3个化合物色谱分离良好，分别在0.298 4~5.968 mg (1)，6.554~131.1 mg (2)，0.262 6~5.252 mg (3)，0.256 8~5.136 mg (4)线性关系良好(r>0.999)，平均加样回收率依次为97.7%，99.1%，98.7%，97.9%。结论 本方法简便、准确，可用于同时测定猫豆中的左旋多巴及其四氢异喹啉类衍生物含量，为其质量控制方法提供参考。

Abstract:

OBJECTIVE To establish a method for simultaneous determination of both L-dopa(2) and its derivates in seeds of Mucuna pruriens var. utilis Burck by HPLC. METHODS Three ingredients, 3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline(1), 1-methyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline(3) and 1,1-dimethyl-3-carboxy- 6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline(4) were isolated from the herb. Chromatographic separation was performed on a Cosmosil C₁₈-PAQ analytical column (4.6 mm×250 mm, 5 mm) with 1% acetic acid as the mobile phase at 30 ℃. The detection wavelength was 280 nm and the flow rate was 0.5 mL·min^-1. RESULTS The 4 components were separated with satisfaction. Their linearity ranges were between 0.298 4-5.968 mg (1), 6.554-131.1 mg (2, L-dopa), 0.262 6-5.252 mg (3) and 0.256 8-5.136 mg (4), respectively with their correlation coefficients all >0.999. Their average recovery rates were 97.7%, 99.1%, 98.7% and 97.9%. CONCLUSION The method is accurate and selective for simultaneous determination of 4 ingredients in seeds of Mucuna pruriens, which could be applied for the quality control of this herb.