Rapid characterization of chemical constituents of Platycodon grandiflorum and its adulterant Adenophora stricta by UPLC-QTOF-MS/MS

Platycodon grandiflorum (PG) is extensively used for treating cough, excessive phlegm, sore throat, bronchitis and asthma, whereas Adenophora stricta (AS) is commonly used to reduce phlegm, clear lung and tonify stomach. Due to similar appearances, PG is sometimes adulterated with cheap AS so as to gain profits. And this will inevitably result in different pharmacological property. In order to further clarify the differences in the chemical composition of these two Chinese herbs, the ultra-high performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry coupled with UNIFI platform was used to establish a reliable, simple, sensitive and rapid analytical method. Seventy-five compounds, including triterpenoid saponins, organic acids, flavonoids, steroids, phenols, etc., were identified from PG based on MSE data and retention time under the optimized conditions. Meanwhile, 57 compounds including triterpenoid saponins, organic acids, steroids, phenols, alkaloids, etc. were identified from AS. Among all the identified compounds, there were only 14 common components (mainly organic acids) existing in two herbs, and most of the other chemical compositions are totally different between the two herbs. Based on the results, AS cannot substitute for PG. In addition, PG adulterated with AS will lead a poor efficacy in clinical application. In addition, the systematic comparison of similarities and differences between two Chinese herbs will provide reliable characterization profiles to clarify the pharmacological fundamental substances.