A new C22 polyacetylene and seven isoprenylated pterocarpans from Erythrina subumbrans.

A new C22 polyacetylene, erysectol A (1), and seven isoprenylated pterocarpans, phaseollin (2), phaseollidin (3), cristacarpin (4), (3'R)-erythribyssin D/(3'S)-erythribyssin D (5a/5b) and dolichina A/dolichina B (6a/6b) were isolated from the twigs and leaves of Erythrina subumbrans. Their structures were determined based on their NMR spectral data. Except for 2-4, all the other compounds were isolated from this plant for the first time. Erysectol A was the first reported C22 polyacetylene from plants. Polyacetylene was isolated from Erythrina plants for the first time.