Tirucallane-type triterpenoids from Dysoxylum lenticellatum.

Ten new tirucallane-type triterpenoids, represented by a rearranged skeleton dysolenticin A (1), dysolenticin B (2), a rare trinortriterpenoid dysolenticin C (3), three tirucallane triterpenoid derivatives with a hemiketal moiety dysolenticins D-F (4-6), dysolenticins G-I (7, 9, 10), and the new alkaloid dysolenticin J (12), together with seven known analogues were isolated from the twigs and leaves of Dysoxylum lenticellatum. Their structures were elucidated by extensive spectroscopic methods, and those of compounds 1, 3, 4, 6, and 10 were confirmed by single-crystal X-ray diffraction experiments. Dysolenticin J (12) showed significant vasodilative effects on intact rat aortic rings with a diastolic degree of 87.4% at 10 μg/mL.