The occurrence of osthol in Leionema ellipticum supports its assignment to the genus Leionema (Rutaceae)

From the above ground parts of Leionema ellipticum (Rutaceae), the new flavonoid 3,4′,5-trimethoxyflavone-7- O-α-rhamnoside, the 8-prenylated coumarin osthol, and the cinnamyl alcohol derivative boropinol-B were isolated and identified. Osthol is of systematic significance as coumarins with this substitution pattern have proved to be very common in species now assigned to Leionema. The presence of osthol in L. ellipticum is, therefore, supportive of a close relationship with other species of Leionema, despite the presence of a number of anomalous morphological features in the flowers.