In our continuing phytochemical screening program aimed at finding major constituents. of endemic Madagascar plants as potential templates for semisynthesis, we investigated the ethyl acetate extract of stem bark of Garcinia verrucosa. Fractionation of the extract led to the isolation of the major compound named garcicosin. -Its structure was elucidated by spectroscopic methods including ID and 2D homo- and heteronuclear NMR techniques (COSY, HSQC, HMBC and NOESY), and HR-mass spectromnetry.