New Rotenoids from the Root Bark of Jamaican Dogwood (Piscidia erythrina L.)

Abstract
A further investigation of the root bark constituents of Jamaican dogwood (Piscidia erythrina) has revealed two new pyrano-rotenoids, (+)-erythynone and (+)-12a-hydroxyerythy-none. Both compounds co-occur with (-)-rotenone, and two additional rotenoids [(-)-12a -hydroxyrotenone and (-)-villosinol] not previously isolated from P. erythrina. Root extracts were also found to contain the rare isoflavone durmillone. The stereochemistry of all five Piscidia rotenoids was examined by ORD and CD spectrometry. These studies indicated that erythynone and 12 a-hydroxyerythynone were antipodal to naturally occurring (-) -6 aS; 12 aS-rotenone at the B/C ring junction.