A rapid assay for angiotensin‐converting enzyme activity using ultra‐performance liquid chromatography–mass spectrometry |
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Authors: | Fang Geng Yuqi He Li Yang Zhengtao Wang |
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Institution: | 1. The MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Zhangjiang Hi‐tech Park, Shanghai 201210, China;2. The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201210, China;3. Shanghai R&D Center for Standardization of Traditional Chinese Medicines,199 Guoshoujing Road, Zhangjiang Hi‐tech Park, Shanghai 201203, China |
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Abstract: | Angiotensin‐converting enzyme (ACE) plays an important role in the renin–angiotensin system and ACE activity is usually assayed in vitro by monitoring the transformation from a substrate to the product catalyzed by ACE. A rapid and sensitive analysis method or ACE activity by quantifying simultaneously the substrate hippuryl–histidyl–leucine and its product hippuric acid using an ultra‐performance liquid chromatography coupled with electrospray ionization‐mass spectrometry (UPLC‐MS) was first developed and applied to assay the inhibitory activities against ACE of several natural phenolic compounds. The established UPLC‐MS method showed obvious advantages over the conventional HPLC analysis in shortened running time (3.5 min), lower limit of detection (5 pg) and limit of quantification (18 pg), and high selectivity aided by MS detection in selected ion monitoring (SIM) mode. Among the six natural products screened, five compounds, caffeic acid, caffeoyl acetate, ferulic acid, chlorogenic acid and resveratrol indicated potent in vitro ACE inhibitory activity with IC50 values of 2.527 ± 0.032, 3.129 ± 0.016, 10.898 ± 0.430, 15.076 ± 1.211 and 6.359 ± 0.086 mm , respectively. A structure–activity relationship estimation suggested that the number and the situation of the hydroxyls on the benzene rings and the acrylic acid groups may play the most predominant role in their ACE inhibitory activity. Copyright © 2009 John Wiley & Sons, Ltd. |
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Keywords: | UPLC‐MS angiotensin‐converting enzyme phenoles hippuric acid hippuryl– histidyl– leucine |
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