Characterization and rapid identification of chemical constituents of NaoXinTong capsules by UHPLC-linear ion trap/Orbitrap mass spectrometry

Abstract

The BuChang NaoXinTong (BNC) capsule is a well-known, traditional, prescribed Chinese medication for the treatment of cardiovascular and cerebrovascular diseases. Nevertheless, the chemical profile of BNC has not been established. In the present study, ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap) has been developed for rapid and high-throughput screening of the preliminary chemical profile of BNC in both positive and negative ion modes. Twenty-five compounds were identified as the standard available compounds by comparing the retention time and high-resolution accurate mass. For the standard unavailable compounds, the structures were presumed based on high-accuracy protonated precursors and multi-stage mass spectrometry (MSn) using the proposed strategy. In particular, flavones, isoflavones, and tanshinones had the same skeleton. Therefore, the standards were utilized to characterize the fragment pathways and diagnostic fragment ions that could be applied for structural elucidation of their derivatives. Meanwhile, all the constituent groups of the compounds were detected in the individual herbs comprising BNC. Finally, a total of 178 components were identified or tentatively characterized in BNC, including 21 flavones and 6 flavone glycosides, 18 phenanthraquinones, and 22 terpenoids. The identification and structure elucidation of these chemicals provide essential data for further phytochemical studies, quality control, and pharmacological studies of BNC.