Oligo‐ and macrocyclic diterpenes in thymelaeaceae and euphorbiaceae occurring and utilized in Yunnan (Southwest China). 2. Ingenane type diterpene esters from Euphorbia nematocypha Hand.‐Mazz

Abstract The highly irritant new Euphorbia factors N 1 and N 2 were isolated as a mixture from latex of E. nematocypha Hand.‐Mazz., by a combination of counter current distribution and chromatographic methods. Spectroscopic and chemical analyses revealed their structures to be 3‐0‐(2,4,6,8‐tetradecatetraenoyl)ingenol (1) and 3‐0‐(2,4,6,8‐pentadecatetraenoyl)ingenol (2), respectively.