title: The succulent euphorbias of Nigeria. III. Structure and potency of the aromatic ester diterpenes of Euphorbia poissonii Pax.
abstract: The latex of Euphorbia poissonii was found to contain irritant aromatic diterpene esters based upon resiniferonol, 12-deoxy-16-hydroxy-phorbol and 12-deoxyphorbol. Four resiniferonol esters, 9,13,14-ortho-phenylacetyl-resiniferonol-20-0-[p-hydroxy-phenylacetate]; 9,13,14-orthophenylacetyl-resiniferonol-20-0-[m-methoxy-m'-hydroxy-phenylacetate]; 9,13,14-orthophenylacetyl-resiniferonol-20-0-acetate and resiniferonol-14-0-phenylacetate-20-0-[m-methoxy-m'-hydroxy-phenylacetate], were identified. Two further esters were identified as 12-deoxy-16-0-[2-methylbutyroyl]-phorbol-13-0-phenylacetate-20-0-acetate and 12-deoxy-16-0-[2-methylbutyroyl]-phorbol-13-0-phenylacetate. These compounds represent the first aromatic esters of this parent diterpene to be obtained from natural sources. The third group of compounds were identified as 12-deoxyphorbol-13-0-[p-hydroxy-phenylacetate]-20-0-acetate; 12-deoxyphorbol-13-0-[p-acetoxy-phenylacetate]-20-0-acetate; 12-deoxyphorbol-13-0-phenylacetate-20-0-acetate and 12-deoxyphorbol-13-0-phenylacetate. The irritant potency of the ten pure compounds was obtained using a mouse ear method for assessment of the irritant dose 50%.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D004423:Ear / Q000187:drug effects; D005260:Female; D051379:Mice; D009549:Nigeria; D010031:Otitis / Q000139:chemically induced; D010703:Phorbol Esters / Q000302:isolation & purification / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D010947:Plants, Toxic / Q000032:analysis*
chemical_list: D004224:Diterpenes; D010703:Phorbol Esters; D010704:Phorbols