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The Scientific World Journal
Volume 2014, Article ID 947946, 11 pages
http://dx.doi.org/10.1155/2014/947946
Research Article

Characterization of Metabolites of Leonurine (SCM-198) in Rats after Oral Administration by Liquid Chromatography/Tandem Mass Spectrometry and NMR Spectrometry

1School of Medicine, Nantong University, 19 Qixiu Road, Nantong 226001, China
2Department of Pharmacology, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong District, Shanghai 201203, China
3Department of Clinical Pharmacy, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong District, Shanghai 201203, China
4Analytical and Testing Center, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong District, Shanghai 201203, China

Received 25 August 2013; Accepted 31 December 2013; Published 24 February 2014

Academic Editors: J.-T. Cheng and M. W. Jann

Copyright © 2014 Qing Zhu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Leonurine, a major bioactive component from Herba Leonuri, shows therapeutic potential for cardiovascular disease and stroke prevention in some preclinical experiments. The aim of this study is to characterize metabolites of leonurine in rats using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC/MS/MS). The chromatographic separation was performed on an Agilent ZORBAX SB-C18 column using a gradient elution with acetonitrile/ammonium acetate buffer (10 mM, pH 4.0) solvent system. An information dependent acquisition (IDA) method was developed for screening and identifying metabolites of leonurine under positive ion mode. Compared with control, the interesting compound in the extracted ion chromatogram (XIC) of the in vivo samples was chosen and further identified by analyzing their retention times, changes in observed mass (Δm/z), and spectral patterns of product ion utilizing advanced software tool. For the first time, a total of three metabolites were identified, including two phase II metabolites generated by glucuronidation (M1) and sulfation (M2) and one phase I metabolite formed by O-demethylation (M3). Finally, the lead metabolite M1 was isolated from urine and its structure was characterized as leonurine-10-O-β-D-glucuronide by NMR spectroscopy (1H, 13C, HMBC, and HSQC).