Nine known alkaloids [(+)-isodomesticine (1), (+)-norisodomesticine (2), (+)-nantenine ( 3), (+)-neolitsine (4), (+)-lirioferine (5), (+)-N-methyllaurotetanine (6), (+)-norlirioferine (7), (+)-isoboldine (8) and (+)-reticuline (9)] were isolated from young leaves of Guatteria dumetorum. Their