Structures of paraensidimerins B, E, F, and G, four new dimeric quinolinone alkaloids from Euxylophora paraensis

Abstract

Paraensidimerins E and F, two new alkaloids from the heartwood of Euxylophora paraensis(Rutaceae), have been shown to be the heptacyclic bis-quinolin-2-one derivatives(1c)and (1d); they are stereoisomers of paraensidimerins A (1a) and C (1b) which have previously been isolated from the same plant, and form part of a new group of alkaloids isolated from this plant, the other two members of which are paraensidimerins G (2) and B (3).