Indole Alkaloids and Quassinoids from the Stems of Brucea mollis

Seven new indole alkaloids, bruceollines H-N (1-7), three new quassinoids, yadanziolides T-V (10-12), and four known analogues, bruceolline E (8), bruceolline F (9), bruceine D (13), and yadanziolide B (14), were isolated from an ethanol extract of the stems of Brucea mollis. The absolute configurations of compounds 2 and 5 were determined by comparison of their experimental and calculated ECD spectra. The absolute configuration of the known compound 9 was determined by using Mo2(OAc)4-induced CD analysis for the first time. Compounds 10, 13, and 14 exhibited cytotoxic activities with IC50 values of 3.00-5.81 μM.