Daphniphyllum alkaloid and iridoid hybrids
Monday, September 30, 2013

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

Fei Wang*, Mei-Fen Mao, Guo-Zhu Wei, Yuan Gao, Fu-Cai Ren, Ji-Kai Liu*

Phytochemistry, 2013, 95: 428-435

   Two Daphniphyllum alkaloid and iridoid hybrids with the hitherto unknown decacyclic fused skeletons, hybridaphniphyllines A (1) and B (2), along with one diamino Daphniphyllum alkaloid, daphnicyclidin I (3), were isolated from dried stems and leaves of Daphniphyllum longeracemosum. Their structures were elucidated on the basis of extensive spectroscopic analysis, and the absolute configuration of daphnicyclidin I was deduced by the CD exciton chirality method. A biogenetic pathway for 1 and 2 involving natural Diels-Alder cycloaddition is proposed.

   ► Three structurally unusual alkaloids were isolated from Daphniphyllum longeracemosum.

   ► Their structures were determined by extensive spectroscopic analysis.

   ► Hybridaphniphyllines A and B represent a hitherto unknown class of natural product hybrids.

   ► Hybridaphniphyllines A and B were possibly generated via Diels-Alder cycloaddition.