Chemical constituents from barks of Eucommia ulmoides / 中草药

ABSTRACT

Objective: To study the chemical constituents of barks of Eucommia ulmoides. Methods: Compounds were isolated by means of normal phase silical gel, reverse phase ODS, Sephadex LH-20 column chromatography, and preparative-HPLC, and their structures were identified on the basis of various spectroscopic analyses, including NMR and HR-ESI-MS. Results: Nine known compounds, including seven flavonoids and two phenylpropanoids, were isolated from the 95% EtOH extract of barks of E. ulmoides. Their structures were identified as licoflavone B (1), 3,5,4’-trihydroxy-7,3’-dimethoxyflavone (2), liquiritigenin (3), formononetine (4), (+)-4’-O-methylglabridin (5), paratocarpin E (6), loureirin C (7), threo-1-(4-hydroxy-3-methoxyphenyl)-1-methoxy-2-{4-[1-formyl- (E)-vinyl]-2-methoxyphenoxy}-3-propanol (8), and diospyrosin (9). Conclusion: Compounds 1-9 are obtained from the genus of Eucommia for the first time.