Isolation of new neolignans and an unusual meroterpenoid from Piper cabagranum

A novel meroterpenoid cabagranin D was isolated with related neolignans cabagranins A–C from the leaves of Piper cabagranum (Costa Rica). Cabagranins A–C represent the first examples of 3,3′-neolignans isolated from the plant genus Piper , and the meroterpenoid cabagranin D displays an unprecedented Diels–Alder conjugate of an unsubstituted phenylpropenone and α-phellandrene. Details of the full structural elucidation of these compounds and a discussion of their potential biosynthetic relationships are presented.