Diprenylated flavanones dorspoinsettifolin

Diprenyleriodictyol (83), the simplest diprenylated flavanone, is a citotoxic compound first reported by Harborne et al in 1993 from Vellozia coronata and V. nanuzae [66]. The structure of dorsmanine E (84) was established from analysis of the spectroscopic data for the presumed natural product as well by synthesizing it from 6, 8-diprenyleriodictyol (83) upon treatment of the latter with methanolic HC1. Dorsmanin B (85) [39] as dorspoinsettifolin (79) and 78 lack the 5-hydroxyl functionality that is common in most of the flavonoids isolated so far from Dorstenia spp and the range of compounds isolated from D. 

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