Quinolizidine alkaloid composition in different organs of Lupinus aschenbornii

ABSTRACT

Lupinus aschenbornii S. Schauer, Fabaceae, grows in the Central Highlands of Mexico, at altitudes between 2800 to 4300 m above sea level. The alkaloid patterns in organs of L. aschenbornii were analyzed by Gas-Liquid Chromatography-Mass Spectrometry (GLC-MS). Quinolizidine alkaloids (QA) were identified according to their mass fragmentation patterns, in combination with their Kovats retention indeces. Total QA content in organs differed substantially seed contained 3.3 mg/g dry weight, flowers 2.8 mg/g DW, leaves 1.9 mg/g DW, stems 1.5 mg/g DW, and pods 1.4 mg/g DW. Roots do not accumulate QA and their profiles differed considerably while seed stored N-formylangustifoline (17 percent), 17-oxolupanine (16 percent), multiflorine (11 percent) and an unidentified alkaloid (n.i.) 2869 (11 percent) as main QA, sparteine was absent. In flowers, sparteine reached 73 percent, in leaves up to 80 percent, in stems up to 32 percent and in pods up to 96 percent. Other QA present were lupanine (32 percent in stem, 9 percent in flower and 7 percent in seed); N-formylangustifoline (9 percent in stem and 4 percent in flower); multiflorine (6 percent in stem and 3 percent in flower). Differences in QA profile might be a strategy of lupins to avoid adaptation of possible predators because the different QA have different pharmacological properties.