Quinolizidine alkaloid status of Acosmium s.s., Guianodendron and Leptolobium, the segregate genera of Acosmium s.l.

Extracts of leaves of five species of Leptolobium, the monospecific Guianodendron and all three species of Acosmium s.s. were examined for the presence of quinolizidine alkaloids by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. The species of Leptolobium all contained one or more of the quinolizidine alkaloids panacosmine, lupanacosmine or isomeric forms, while leaves of Guianodendron praeclarum accumulated guianodendrine, a previously unreported quinolizidine alkaloid with a novel skeleton. Quinolizidine alkaloids could not be detected in leaves of any of the three species of Acosmium s.s., which were found to accumulate stachydrine. The quinolizidine alkaloid status of Acosmium s.s, Guianodendron and Leptolobium agrees with their segregation from Acosmium s.l. and the exclusion of Acosmium s.s. from the genistoid clade of legumes, as suggested by morphological characters and molecular phylogenies.