Pentacyclic triterpenoid esters from the fruits of Bruguiera cylindrica

Six new pentacyclic triterpenoid esters (1-6) together with 3alpha- and 3beta-taraxerol were isolated from the fruits of Bruguiera cylindrica. The structures of the new compounds were characterized as 3alpha-E-feruloyltaraxerol (1), 3alpha-Z-feruloyltaraxerol (2), 3beta-E-feruloyltaraxerol (3), 3beta-Z-feruloyltaraxerol (4), 3alpha-E-coumaroyltaraxerol (5), and 3alpha-Z-coumaroyltaraxerol (6), respectively. Compounds 2 and 6 exhibited weak cytotoxicity against the NCI-H187 cell line.