Monoglycerol ester, galloylglucoside and phenolic derivatives from Gymnosporia senegalensis leaves

Abstract

Phytochemical investigation of the leaves of Gymnosporia senegalensis (Lam.) Loes. led to the isolation and characterization of eighteen compounds: one new polyunsaturated fatty acid-derived monoglyceride, (2S)-1-O-(4′Z,7′Z,10′Z-octadecatrienoyl) glycerol (1); four galloylglucoside derivatives (2–5), including one new named (2R)-methyl [(6′-O-galloyl)-β-D-glucopyranosyloxy]phenylacetate (2), eleven phenolics (6–16), and two sterols (17–18). The structures of the isolates were determined by means of spectroscopic and spectrometric data, as well as by comparison with literature data. Galloylglucosides, especially cyanogenic constituents (3, 4) are described here for the first time in the genus. Antibacterial and cytotoxic activities of isolated compounds were investigated. None of the tested compounds showed growth inhibition against Staphylococcus aureus NBRC 13276, Bacillus subtilis NBRC 3134 and Escherichia coli NBRC 3972 at 50 μM, while 1, 7, 9, 17, and 18 at 50 μM showed relatively weak to moderate decrease of viability against colon (DLD1), breast (MCF7) and gastric (MKN45) cancer cells. Furthermore, the chemotaxonomic significance of the isolated compounds was discussed.