First report of isolation of antibacterial ceramides from the leaves of Euclinia longiflora Salisb

Abstract

Two phytosphingosine-type ceramides (euclinide A (1) and B (2)) were isolated alongside one fatty acid (geddic acid (3)), one fatty acid-1-glyceride ((2S)-1-O-hentriacontanoyl glycerol (4)), ten triterpenes (α-amyrin (5), α-amyrin acetate (6), ursolic acid (7), β-amyrin (8), β-amyrin acetate (9), β-amyrin palmitate (10), oleanic acid (11), maslinic acid (12), betulinic acid (13) and cylicodiscic acid (14)) and four sterols (β -sitosterol (15), stigmasterol (17), and their glucosylated derivatives β-sitosterol-3-O-β-glucopyranoside (16) and stigmasterol-3-O-β-glucopyranoside (18)) from the methanol extract of the leaves of Euclinia longiflora Salisb. using routine chromatographic methods. The structures of the new ceramides and known compounds were determined by analyses of HR-FAB-MS, 1D and 2D NMR (HSQC, HMBC, and NOESY) data and confirmed, where applicable, by comparison with data reported in literature. The methanolic extract and the ceramides were evaluated for their antibacterial activities against different bacterial strains using microdilution method and the MIC values ranged from 6.25 to 50 μg/mL and were considered as moderate activity compared to ciprofloxacin. It is the first report of ceramides in Euclinia longiflora.