3-Aminofurostane Alkaloids from Solanum paniculatum (“Jurubeba Verdadeira”) Roots

Abstract

The roots of Solanum paniculatum (Solanaceae) have extensively been used in folk medicine to treat liver infections and as a diuretic. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) were used for the profiling and structural characterization of alkaloids from the roots of S. paniculatum. Sixteen 3-aminofurostane alkaloids were characterized as novel compounds. In this study, three principal alkaloids were isolated in mixture, and their structures were established by different spectroscopic methods, including 1D, 2D nuclear magnetic resonance (NMR) experiments, and the high-resolution electrospray ionization (HR-ESI)-MS analysis. The isolated alkaloids were used to explore fragmentation pathways. Compound identification was based on the exact mass and fragmentation behaviors. Two compounds were identified as new natural compounds as: (25R)-3β-amino-furost-5-en-22α,26-diol O(26)-β-D-glucopyranoside (fatimagraine) and (25R)-3β-amino-furost-22-en,26-ol O(26)-β-D-glucopyranoside (bhattacharyyaine). The unambiguous assignments of 1H and 13C NMR data and chemical correction of the structure alkaloid jurubine are reported for the first time.