Plumeran Alkaloids and Glycosides from the Seeds of Aspidosperma pyrifolium Mart

The residual aqueous fraction of the liquid-liquid partition of the ethanol extract from seeds of Aspidosperma pyrifolium showed antinociceptive and anti-inflammatory activities in the formalin test, abdominal writhing induced by acetic acid, and paw edema induced by carrageenan. Its phytochemical analysis led to the isolation of a new alkaloid with a rearranged plumeran skeleton, the (-)-(3S,7S,21R)-rel-(3αH)-15(14→3)-abeo-2,16,17,20,6,7-hexahydro-15H,8aH,16a,20a-ethano-1H-indolizino[3,1-cd]carbazole, in addition to six other known plumeran alkaloids, one tetrahydro-β-carboline alkaloid, and the glycosides of two iridoids and of salycilic acid, that are being reported for the first time for A. pyrifolium. One of the known alkaloids is being reported for the first time from a natural source. The nuclear magnetic resonance (NMR) data, and the correspondent assignments, of some alkaloids already reported in the literature are suggested to be revised. Structures of all compounds were characterized by 1D and 2D NMR and Fourier transform infrared (FT-IR) spectroscopies and high-resolution electrospray ionization mass spectrometry (HRESIMS), and comparison with data from literature.