Sesquiterpenoids from the barks and roots of Michelia alba collected in Xuan Mai town, Hanoi City, Viet Nam

AbstractEight sesquiterpenoids including costunolide (1), parthenolide (2), 11α,13‐dihydroparthenolide (3), 9β‐hydroxy‐dihydroparthenolide (4), (‐)‐bisparthenolidine (5), 11α,13‐dihydro‐β‐cyclocostunolide (6), α‐cadinol (7), magnograndiolide (8) were isolated from the barks and roots of Michelia alba. The structures of these compounds were elucidated by spectroscopic methods (MS, 1D and 2D NMR) and comparison with the reported data. Compounds 5‐8 have been isolated for the first time from Michelia alba.