Amygdaloidins A–L, twelve new 13 α-OH jatrophane diterpenes from Euphorbia amygdaloides L.

Abstract Twelve new diterpenes, named amygdaloidins A–L ( 1 – 12 ), possessing a unique substitution pattern of the jatrophane skeleton, have been isolated from the wood spurge, Euphorbia amygdaloides L. (Euphorbiaceae). The chemical structures of amygdaloidins A–L have been established through a combination of extensive nuclear magnetic resonance and mass spectrometry methods. To deeper investigate the conformations adopted by such compounds in solution, we have carried out a molecular mechanic and dynamics calculation on amygdaloidin A and on the previously isolated euphodendroidin I. The data obtained gave further information on the endo - and exo -type conformations, the two main orientations of the jatrophane diterpenes.