Alkaloids from Spathelia excelsa: their chemosystematic significance.

The methanol extract from the leaves of Spathelia excelsa yielded six alkaloids: 2-(12-oxo-tridecanyl)-3-methoxy-4-quinolone, 2-(10-hydroxy-10-methyldodecanyl)-3-methoxy-4-quinolone, 2-(11-hydroxy-11-methyldodecanyl)-3-methoxy-4-quinolone, 2-(12-hydroxytridecanyl)-3-methoxy-4-quinolone, 7-hydroxy-2-(3-hydroxy-3-methylbutyl)-4-quinolone and 6-hydroxy-2-(3-hydroxy-3-methylbutyl)-4-quinolone, in addition to the known 3-O-beta-d-glucopiranosylsitosterol and (-)-epicatechin. The 2-alkyl-4(1H)-quinolones in S. excelsa display strong similarities with those in Dictyolomatoideae, which contains several 2-alkyl-4-quinolones. The data reported herein thus provide firm support for placing Spathelioideae close to or within the Dictyolomatoideae.