Hybridaphniphyllines A and B, Daphniphyllum alkaloid and iridoid hybrids suggestive of Diels-Alder cycloaddition in Daphniphyllum longeracemosum

Two Daphniphyllum alkaloid and iridoid hybrids, hybridaphniphyllines A (1) and B (2), along with one diamino Daphniphyllum alkaloid, daphnicyclidin I, were isolated from Daphniphyllum longeracemosum. Natural Diels-Alder cycloaddition is suggested in the biogenetic pathway to 1 and 2.