Rapid differentiation of herbal medicines by matrix-assisted laser desorption/ionization mass spectrometry

Abstract

A matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)-based approach has been developed and demonstrated for rapid differentiation of herbal medicines in this study. This approach typically involved a brief extraction to a small amount of herbal powder followed by MALDI-MS analysis. The MALDI-MS spectra obtained were characteristic of the herbal species and thus could act as the fingerprints of the species. This approach was used to differentiate between Panax ginseng (Asian ginseng) and Panax quinquefolius (American ginseng), between Schisandrae sphenanthera (southern magnoliavine fruit, Nan-Wuweizi) and Schisandrae chinensis (northern magnoliavine fruit, Bei-Wuweizi), and among Angelica sinensis (Chinese Danggui), Angelica acutiloba (Japanese Danggui), Angelica gigas (Korean Danggui) and Angelica archangelica L. (Europe Danggui). The results revealed that unambiguous differentiation could be achieved in each case, based on the mass patterns or principal component analysis of their respective MALDI spectra. Direct analysis of herbal powder or small pieces of raw samples by MALDI-MS, which avoids the extraction and/or homogenization procedures, was attempted and the acquired spectra also allowed differentiation of the herbal medicines. The approach developed in this study is simple, rapid, robust, and can be used for analysis of other herbal medicines.