Minor ent-abietane diterpenoids from Euphorbia guyoniana.

Three new abietane-type diterpenoids: ent-abieta-8,11,13-trien-16-ol (1), ent-abieta-8,11,13-trien-11,16-diol (2) and 11,12-dihydroxy-7-oxo-ent-abieta-8,11,13-trien-16-oic acid methyl ester (3), in addition to three known triterpenoids: euphol (4), 24,25-epoxycycloartanol (5) and beta-sitosterol O-beta-D-glucoside (6) were isolated from the chloroform extract of the roots of Euphorbia guyoniana. Structures of the isolated compounds were established on the basis of spectroscopic analyses, including 1D and 2D homo and heteronuclear NMR experiments and ESIMS, and comparison with literature data.