Flavonoids from roots of Ephedra sinica / 中草药

ABSTRACT

Objective: To study the flavonoids from the roots of Ephedra sinica in Ephedra Tourn. ex L. Methods: The roots of E. sinica were extracted with 90% ethanol, and isolated and purified by silica gel, Sephadex LH-20, and RP-18 gel column chromatography. All the compounds were identified based on spectral analyses (including MS, 1H-NMR, and 13C-NMR). Results: Thirteen flavonoids were isolated from the roots of E. sinica and were characterized as ephedrannin A (1), mahuannin A (2), mahuannin B (3), mahuannin D (4), apigenin (5), kaempferol (6), quercetin (7), dihydroquercetin (8), 3′, 4′, 5, 7-tetrahydroxy flavanone (9), (+)-catechin (10), (-)-epi-catechin (11), afzelechin (12), and (-)-epi-afzelechin (13), respectively. Conclusion: Compounds 7-13 are obtained from this plant for the first time.