Isolation and Determination by HPLC of Polar Constituents from Scrophularia ningpoensis
JER-HUEI LIN, YOE-RAY KU, YUHN-SHENG HUANG, FANG-MEIR YARN, KUO-CHING WEN AND *WENG-FONG HUANG
National Laboratories of Foods and Drugs,Department of Health, Executive Yuan 161-2, Kuen Yang Street, Nankang, Taipei, Taiwan, R.O.C
*Graduate Institute of Health & Welfare Policy, National Yang-Ming University, Shih-Pai, Taipei 11221, Taiwan, R.O.C
ABSTRACT
Three polar constituents, 2-(3-hydroxy-4-methoxyphenyl) ethyl 1-O-[α -L-arabinopyranosyl (1→6)]-feruloyl(1→4)]- α-L-rhamnopyranosyl(1→ 3)- β-D-glucopyranoside(SN-A), harpagoside(SN-B) and cinnamic acid(SN-C) have been isolated from Scrophularia ningpoensis by a modified isolation method. These constituents were used as marker substances for quality analysis of Scrophulariae Radix. In this study we have also developed a high performance liquid chromatographic method for simultaneous determination of above marker substances in Scrophulariae Radix. This performance was done by using a gradient elution with a solution of acetonitrile in 1.0% acetic acid on a ODS column. The linear calibration ranges were SN-A 20-150μg/ml ( r=0.9907 ), SN-B 5-50 ug/ml ( r=0.9994 ) and SN-C 20-200μg/ml ( r=0.9981 ). Recoveries were SN-A 100.47± 3.23%, SN-B 98.49± 2.62% and SN-C 96.15± 4.39%. The relative standard deviations of three marker substances for intraday and interday analyses were 0.93-1.01% and 0.28-1.97%.. The contents of three marker substances in 24 crude drugs of Scrophulariae Radix were SN-A 0.05%~1.71%, SN-B non detected~0.17%, and SN-C 0.06%~0.53%, respectively.
Key words : Scrophulariae Radix, Scrophularia ningpoensis, harpagoside, HPLC