Structure elucidation of erythrosotidienone and erythromotidienone -: Two new isoquinoline alkaloids from Erythrina variegata flowers

Careful examination of the acetone extract of the Erythrina variegata flowers has revealed the presence of five compounds, three of which are identified as stigmasterol (1), cycloartenol (2) and erysotramidine (13). The remaining two compounds are new isoquinolines whose structures have been established on the basis of chemical correlation, derivatization and ir, H-1 nmr, C-13 nmr and mass spectral analysis. They are tentatively named as erythrosotidienone (4) and erythromotidienone (10). Cycloartenol (2) has been isolated for the first time from Erythrina species. The occurrence of the new compounds 4 and 10 is of interest from the biogenetic point of view.