Azaphenanthrene Alkaloids with Antitumoral Activity from Anaxagorea dolichocarpa Sprague & Sandwith (Annonaceae)

Phytochemical investigation of Anaxagorea dolichocarpa Sprague & Sandwith led to isolation of three azaphenanthrene alkaloids: eupolauramine, sampangine and imbiline 1. Their chemical structures were established on the basis of spectroscopic data from IR, HR-ESI-MS, NMR (including 2D experiments) and comparison with the literature. Sampangine and imbiline 1 are being described in the Anaxagorea genus for the first time. Eupolauramine and sampangine show concentration-dependent antitumoral activity in leukemic cells K562 with IC50 of 18.97 and 10.95 μg/mL, respectively.