New tetracyclic sesterterpenes from Cydonia vulgaris

The CHCl 3 -MeOH extract of Cydonia vulgaris Pers. (Rosaceae) was shown to contain four new sesterterpene esters, namely 24,25-O-diacetylvulgaroside (1), 25-O-acetylvulgaroside (2), 24-O-acetyl-25-O-cinnamoylvulgaroside (3), and 25-O-cinnamoylvulgaroside (4). The structure elucidation of these compounds was accomplished using homonuclear and heteronuclear 2D-NMR experiments and FABMS.