New mirsinane-type diterpenes from Euphorbia microsciadia Boiss. with inhibitory effect on VEGF-induced angiogenesis

Euphorbia microsciadia (Euphorbiaceae) is a perennial plant growing in Iran. Two new cyclomyrsinol esters, 3-O-propionyl-5, 10, 14-O-triacetyl-8-O-(2'-methyl-butanoyl)-cyclomyrsinol (1) and 3, 5, 10, 14, 15-O-pentaacetyl-8-O-isobutanoyl-cyclomyrsinol (2) were isolated from the methanolic extract of its dried aerial parts. The structures were elucidated based on (13)C- and (1)H-NMR as well as 2D-NMR, IR and different MS spectra. Anti-angiogenic activity was also evaluated on vascular endothelium growth factor (VEGF)-induced angiogenesis in cultured human umbilical vein endothelial cells in vitro by assessing capillary-like tube network formation.