Liriodenine, structure

An investigation of the alkaloidal content of the Australian Eupomatia laurina R. Br. (Eupomatiaceae), yielded a number of alkaloids, among which are the oxoaporphine liriodenine and the 7-hydroxynoraporphine norushinsunine. A new minor alkaloid from this source is eupolauridine (48) whose structure was proven conclusively by total synthesis (Scheme 6). ... 

These data, together with the observation that members of the Magnoliaceae are known to produce benzyhsoquinoline alkaloids, were sufficient for Taylor to propose the now accepted structure for the alkaloid. As final confirmation Taylor synthesized liriodenine by an unambiguous route starting with the known dibydroisoquinoline Ic, Scheme 1 (9). 

Sixty-eight oxoaporphines were isolated from various Annonaceous plants, liriodenine (XI. 18) being ubiquitous. From the structural point of view, these oxoaporphines are rarely substituted at positions 4, 5, 8, and 11. 

The leaves of this plant, native to New South Wales, yielded the known liriodenine and the ubiquitous choline. Also present A (mp 247°) B, C28H15O4N (mp 175°) BHI (mp 192°) C (mp 251°) D (mp 159°) doryafranine, C19H21O3N (mp 94°), which was shown to have structure XXX by a synthesis of the dl-iovm and doryanine, C11H9O3N (mp 162°), also prepared synthetically and shown to have structure XXXI (82). 

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