Identification of chemical composition and metabolic analysis of flavonoids in flowers of Tilia miqueliana Maxim.

Abstract

Abstract [Objective] To lay a foundation for the use of multi-omics methods to explore the metabolic pathways and regulatory mechanisms of important medicinal compounds of Tilia miqueliana Maxim. and to provide a basis for the harvesting of flowers, the chemical composition of T . miqueliana flowers, the content changes of its signature components (flavonoids) at different growing stages were investigated. [Methods] The 10-year-old T . miqueliana was used as the test material. The experiments were conducted to analyze chemical components of flowers and differences in flavonoid contents using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). [Results] (1) A total of 46 compounds were identified, including 13 organic acids and their derivatives, 4 coumarins and their derivatives, 1 ester, and 28 flavonoids. (2) Flower opening stage was the cut-off point for significant changes in metabolites. Compared with the bud stage, the metabolites changed more significantly during flowering. (3) Multiple comparison analysis showed that the content of 26 flavonoids differed significantly (P <0.05) in flowers at different phenological stages. Afzelin, kaempferitrin, quercitrin, hesperidin, taxifolin, and apigenin 7-O-glucuronide were higher at flower opening stage. Final bud stage had higher concentration of proanthocyanidin A2 and three proanthocyanidin trimers. [Conclusion] The development status may be an important factor in determining the content of secondary metabolites in the flowers of T . miqueliana. The signature compound at the final bud stage was proanthocyanidin A2 and at full bloom stage was apigenin-7- O-glucuronide, both of them were valuable for harvesting.

Keywords

• tilia miqueliana maxim.
• linden flowers
• metabolomics
• flavonoids
• uplc-ms/ms