OLIGOCYCLIC AND MACROCYCLIC DITERPENES IN THYMELAEACEAE AND EUPHORBIACEAE OCCURRING AND UTILIZED IN YUNNAN (SOUTHWEST CHINA) .6. TIGLIANE TYPE DITERPENE ESTERS FROM LATEX OF EUPHORBIA-PROLIFERA

Five tigliane type diterpene esters were isolated from the latex of Eu phorbia prolifera Buch-Hom by means of Craig distribution followed by thin layer chromatography. Structural elucidations were done by spectr oscopic methods (MS, NMR) and revealed the following Euphorbia factors : Pr1 to be a 12,13-diester of 4,20-dideoxyphorbol (12-benzoate-13-iso butyrate), Pr2, Pr3: to be 12,13-diesters of 4,20-dideoxy-5xi-hydroxyp horbol (12-benzoate-13-isobutyrate and 12,13-diisobutyrate, respective ly), Pr4/Pr5: to be a mixture of 12,13-diesters of 4-deoxyphorbol buty rate/12-(2,4,6-decatrienoate)-13-isobutyrate]. All compounds were assa yed on the mouse ear for irritant activity: Pr1 was weakly and the mix ture Pr4/Pr5 was highly active, Pr2 and Pr3 were practically inactive.