New quinolinone alkaloids from the heartwood of, Euxylophora paraensis

Abstract

The heartwood of Euxylophora paraensis Hub. (Rutaceae) has given N-methylflindersine (2),spectabiline (3), skimmianine (4) and two new alkaloids, identified from spectroscopic data as 4-hydroxy-2,2,6-trimethyl-3,4,5,6-tetrahydro-2H-pyrano[3,2-c]quinolin-5-one (5) and 4-(2,3-dihydroxy-3-methylbutoxy)-1-methylquinolin-2(1H)-one (6). Five new dimeric quinolinone alkaloids, C₃₀H₃₀N₂O₄, were isolated. The structure of one of these, paraensidimerin D, has now been shown by single-crystal X-ray diffraction methods to be (11), viz. (6aα,7α,14aα)-6,6,9,16- tetramethyl-7-(2-methylprop-1-enyl)-6,6a,7,9,14a,16-hexahydro-8H,15H- quino[3'',4'':5',6'] pyrano [2',3':4,5] pyrano-[3,2-c]quinoline-8,15- dione.