THE ALKALOID PATTERN OF PLAGIOCARPUS-AXILLARIS (FABACEAE, BRONGNIARTIEAE)

As part of a detailed survey of alkaloids in the tribe Brongniartieae, the alkaloid pattern of the monotypic genus Plagiocarpus has been inv estigated. All extracts contained the quinolizidine alkaloids spartein e and cytisine as major compounds. Moreover beta-isosparteine, 11,12-d ehydrosparteine, 17-oxosparteine and anagyrine represented major alkal oids in some extracts. A group of sparteine derivatives, especially re markable amongst them three different hydroxysparteines, and the bicyc lic alkaloid lupinine contributed to the alkaloid profile as minor con stituents. The co-occurrence of lupinine- and alpha-pyridone-type alka loids connects this genus with the other Australian members of the Bro ngniartieae and confirms the monophyly of this tribe. The alkaloidal d ata support the idea that Plagiocarpus is more closely related to Temp letonia incana, T. biloba and Lamprolobium than it is to Hovea and the remaining species of Templetonia. The presence of hydroxysparteines i n both taxa could point to an especially close link of Plagiocarpus an d T. incana.