Flavonoids in leaves of Alstonia scholaris

Objective: To investigate the flavonoids in leaves of Alstonia scholaris,an ethno-remedy of Dai People in Yunnan.Method: The chemical constituents were isolated and purified by column chromatography.Their structures were elucidated on the basis of spectroscopic evidences and physicochemical properties.Result: Eight flavonoids were isolated and identified as kaempferol(1),quercetin(2),isorhamnetin(3),kaempferol-3-O-β-D-galactopyranoside(4),quercetin-3-O-β-D-galactopyranoside(5),isorhamnetin-3-O-β-D-galactopyranoside(6),kaempferol-3-O-β-D-xylopyranosyl-(2-1)-O-β-D-galactopyranoside(7),quercetin-3-O-β-D-xylopyranosyl-(2-1)-O-β-D-galactopyranoside(8).Conclusion: Flavonoids 1-7 were isolated from A.scholaris for the first time.