Study on Chemical Components and Anti inflammatory Activities of Red Bean Tree Branches
The red bean tree (Ormosia hosiei. Hemsl.&E.H. Wilson) is a Fabaceae plant belonging to the Ormosia genus, also known as the He’s red bean tree or the Western Hubei red bean tree. It is mainly distributed in Fujian, Guangdong, Guangxi, Yunnan, and other places, and is a precious local tree species promoted in Fujian Province. It has a large artificial planting area, abundant resources, and high medicinal value. Its roots, stems, leaves, and seeds can all be used as medicine, which can be used to treat injuries caused by falls, rheumatoid arthritis, and blood stasis and amenorrhea. In She ethnic settlements such as Longyan and Ningde in Fujian, the use of red bean branch and leaf decoction for the prevention and treatment of cardiovascular and cerebrovascular diseases is common. However, there are few reports on the research related to these pharmacological effects. In terms of chemical composition research, scholars at home and abroad have isolated and identified various types of components including alkaloids, terpenes, flavonoids, lignans, and volatile oil components from red bean trees and their related plants. The research group has been committed to the development and utilization of medicinal value of red bean trees. In the early stage, various active ingredients with antibacterial and anti-tumor properties have been isolated and identified from the roots, seeds, and branches of red bean trees. This article continues to study the chemical composition of red bean tree branches, and separates, purifies, and identifies 11 flavonoids and their glycosides. Using a mouse BV-2 microglial cell model induced by lipopolysaccharide (LPS), the secretion of inflammatory cytokine interleukin-6 (IL-6) is measured to explore the anti-inflammatory activity of the compounds, in order to provide theoretical basis for the further development of the medicinal value of this plant.

This article isolated and identified 11 flavonoids and their glycosides from red bean twigs, belonging to flavonoids (1-6), flavonoids (7,8), and dihydroflavonoids (9-11). Compound 1 is a new compound, and the hydrogen and carbon spectra data of compound 2 are provided for the first time.

Natural flavonoids have a wide range of pharmacological activities such as antioxidant, anti-inflammatory, anti-tumor, cardiovascular system protection, antibacterial, and neuroprotective. Compounds 4, 9, and 10 have been reported to have good antioxidant activity, compound 6 has anti-inflammatory and anti-tumor activity, and compound 8 has anti-inflammatory, uric acid lowering, and antioxidant activity. This article reports for the first time the activity of compounds 3, 4, and 9 from the branches of red bean trees in inhibiting the inflammatory factor IL-6. The results show potential anti-inflammatory activity and validate the folk anti-inflammatory effect of red bean trees, laying the foundation for further development of anti-inflammatory active ingredients of red bean trees.