Qualitative and quantitative analysis on the chemical constituents in Orthosiphon stamineus Benth. using ultra high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

A sensitive and efficient method was established and validated for qualitative and quantitative analysis on the chemical constituents in Orthosiphon stamineus Benth. (O. stamineus) using ultra high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Based on the retention time and MS spectra, 61 compounds were detected by using ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry. 52 chemical structures in the O. stamineus extracts including 26 phenolic acids, 11 flavonoids, 6 diterpenoids, 4 fatty acids and 5 tanshinones were tentatively identified without the time-consuming process of isolation. Moreover, five chemical constituents (Danshensu, Caffeic acid, Rosmarinic acid, Sinensetin and Eupatorin) were quantified in three different batches of O. stamineus samples by the developed ultra high-performance liquid chromatography coupled with electrospray ionization triple-quadrupole mass spectrometry method in 10 min. The method validation of the five compounds was performed with acceptable linearity (R2, 0.9930-0.9997), precision (RSD, 1.87-10.36%), repeatability (RSD, 0.59-4.87%) and recovery (105.30-110.53%, RSD ≤ 13.90%).