(±)-Bocconarborines A and B, Novel 1,3-Bis-Benzo[c]phenanthridinyl Acetone Alkaloids from Bocconia arborea

Chemical examination of the aerial parts of Bocconia arborea (Papaveraceae), a plant used in traditional medicine, led to the characterization of (±)-6-acetonyldihydrosanguinarine (1), (±)-6acetonyldihydrochelerythrine (2), (±)-6-methoxydihydrochelerythrine (3), (±)-sanguidimerine (4), chelidimerine (5), and the novel constituents (±)-bocconarborine A ((6R,6’S + 6S ,6’R)-13-(6-hydrosanguinarinyl)-15-(6’-hydrochelerythrinyl)-acetone, 6) and (±)-bocconarborine B ((6R,6’R + 6S,6’S)-13-(6-hydrosanguinarinyl)-15-(6’hydrochelerythrinyl)-acetone, 7). The structure and stereochemistry of the novel structures were determined by analyzing the preferred conformations and the spectroscopic data. Antimicrobial evaluations revealed that 3 exhibited activity against S. aureus, S. faecalis and C. albicans.