Cytotoxicity of Triterpenoid Alkaloids from Buxus microphylla against Human Tumor Cell Lines

Abstract

Three Three new new triterpenoid triterpenoid alkaloids, alkaloids, namely namely buxmicrophyllines buxmicrophyllines P-R P-R (1-3), (1-3), were were isolated isolated from from the the twigs twigs and and leaves leaves of of Buxus Buxus microphylla. microphylla. Their Their structures structures were were elucidated elucidated on on the the basis basis of NMR of NMR and and MS MS spectroscopic spectroscopic analyses. analyses. Structurally, Structurally, compounds compounds 1-3 1-3 belong belong to to the the 9,10-cycloartane 9,10-cycloartane type type alkaloids. alkaloids. In In addition, addition, compound compound 3 exhibited exhibited moderate moderate cytotoxic cytotoxic activities activities in in vitro vitro against against HL-60, HL-60, SMMC-7221, SMMC-7221, A-549, A-549, MCF-7, MCF-7, and and SW480 SW480 cell cell lines lines (with (with IC50 values ranging from 4.51 to 15.58 μM). IC50 values ranging from 4.51 to 15.58 μM).