Screening and analyzing the potential bioactive components from rhubarb, using a multivariate data processing approach and ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry

The root of Rheum palmatum L., known as rhubarb, has been widely used in the treatment of obstipation, gastrointestinal indigestion and other diseases in China and other Asian countries for thousands of years. However, the constituents absorbed into the blood after oral administration of rhubarb remain unknown. Here, a sensitive and rapid method using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS) technology combined with a multivariate data processing approach (MDPA) was established to investigate the absorbed constituents in rats after oral administration of rhubarb. Chromatographic fingerprints of the rhubarb samples were firstly established in the negative mode in vitro and in vivo, with 80 compounds found in rhubarb and 41 compounds found in rat plasma after oral administration of rhubarb. Of the 80 compounds detected in vitro, 78 were tentatively characterized. Of the 41 compounds identified in rat plasma, 19 were the original form of compounds absorbed from the 30 compounds detected in vitro, and 11 were the metabolites of compounds that existed in rhubarb. The integrative UPLC/Q-TOF-MS/MS and MDPA method were successfully applied for the rapid determination of multiple components from rhubarb. Based on the significance of these results, this method demonstrated that this method was a useful technique for rapid screening and identifying bioactive components from complex herbal medicines.