Three new steroidal glycoalkaloids from Solanum pseudoquina A. St.-Hil. (Solanaceae)

Abstract

Three new steroidal glycoalkaloids (SGA) were isolated from green berries of Solanum pseudoquina A. St.-Hil. The extract obtained after treatment with 5% acetic acid aqueous solution was subjected to several chromatographic procedures, leading to an enriched alkaloidal fraction. The enriched alkaloidal fraction was subjected to a semi preparative high performance liquid chromatography (HPLC) leading to the isolation of three new SGA from S. pseudoquina: 3-O-(β-D-glucopyranosyl) (20S,25S)-22,26-epimino-16α-acetyl-cholesta-22(N)-ene, 3-O-(β-D-glucopyranosyl) (20R,25ξ)-23,26-epimino-16α-acetyl-cholesta-5,23(N)-dien-22-one and 3-O-(β-D-glucopyranosyl) (20S,25ξ)-23,26-epimino-16α-acetyl-cholesta-5,23(N)-dien-22-one. The structures of the new compounds were elucidated with the help of 1D and 2D nuclear magnetic resonance (NMR) and infrared spectroscopy together with high resolution electrospray ionization and atmospheric pressure chemical ionization mass spectrometry.