Four new daphnane-type diterpene esters (4~ 7) with 5/J, 12/J-dihydroxyresiniferonol-6a, 7a- oxide as a parent alcohol were isolated from the roots of Daphne odora Thunb., together with odoracin (1), odoratrin (2) and gniditrin (3). As a result of the examination of ornithine decarboxylase-inducing activity in mouse skin, both the 9, 13, 14-orthoester formation and the acylation of the hydroxy group at C-12 were necessary for the activity. Furthermore, the ...
