A new prenylated isoflavone and triterpenoids from Erythrina eriotriocha

In addition to known triterpenoids maniladiol [6] and serrat-14-ene-3 beta,21 alpha-diol [7], two new compounds, one oleanane derivative designated as 28-acetoxyerythrodiol [1] and one isoflavone designated as 5,4'-dimethoxy-3'-prenylbiochanin A [5], have been isolated and characterized from the CHCl3 extract of the stem bark of Erythrina eriotriocha. Their structures have been established on the basis of the spectrocopic techniques (ir, nmr, uv, ms) and chemical evidence.