Chemical profiles and quality evaluation of Buddleja officinalis flowers by HPLC-DAD and HPLC-Q-TOF-MS/MS

The dried flowers and inflorescences of Buddleja officinalis Maxim are used as traditional medicines in China, and aqueous extracts of the flowers have also been used since ancient times as a yellow rice colorant at local festivals. In this study, HPLC-Q-TOF-MS/MS was used to determine the overall chemical composition of this medicine-food plant. A total of 54 compounds, including 23 flavonoids, 19 phenylethanoid glycosides, 7 alkaloids and 5 other compounds, were detected in the methanol extracts of the herb using this method. Among them, 35 compounds were found firstly in this herb. HPLC fingerprints were also developed, together with a method for the simultaneous quantification of 11 constituents that could be used for quality evaluation of B. officinalis. Fingerprint analysis, using 28 characteristic fingerprint peaks, was used to assess the similarities among 12 samples collected from different geographic areas and showed that the similarity was >0.900. Simultaneous quantification of 11 markers in B. officinalis was then performed to determine consistency of quality. Additionally, the total phenolic content and antioxidant capacity of extracts of the 12 samples of B. officinalis flowers were measured using spectroscopic methods. B. officinalis was found to have good antioxidant capacity and to be a potential natural antioxidant. The highest antioxidant capacity was found in the samples from Guizhou, Sichuan and Guangxi Province. Our results provide valuable information for further understanding and exploiting the herb.