A New Ceramide (Rumexamide) and Other Chemical Constituents from <i>Rumex abyssinicus</i> Jacq (Polygonaceae): Isolation, Characterization, Antibacterial Activities and Chemophenetic Significance

The chemical study of Rumex abyssinicus Jacp (Polygonaceae) led to the isolation a new ceramide named (R)-2'-hydroxy-N-[(2S,3S,4R,16E)-1,3,4-trihydroxyhexacos-16-en-2-yl]hexadecanamide (rumexamide) (1) together with sixteen known compounds: bis-(2-ethylhexyl) phthalate (2), chrysophanol (3), physcion (4), citreorosein (5), emodin (6), chrysophanein (7), physcionin (8), lupeol (9), 3?,28-dihydroxylup-20(29)-ene (10), 3?-dihydroxylup-20(29)-en-28-oic acid (11), oleanolic (12), ergosta-6,22-diene-3,5,8-triol (13), stigmastane-3,6-dione (14), mixture ?-sitosterol (15) and stigmasterol (16), 3-O-?-D-glucoside (17). Their structures were determined by interpretation their spectroscopic 1D NMR (1H 13C NMR), 2D (COSY 1H-1H, HSQC HMBC) data in conjunction mass spectrometry (TOFESIMS HR-TOFESIMS) comparison those reported literature. Among all compounds, twelve (2, 5, 8-17) firstly isolated from abyssinicus, seven 10-14 17) genus three (13, 14, family Polygonaceae. vitro antibacterial activities extracts (MeOH, n-BuOH EtOAc), as well compounds 9, 11, 12, 15 + 16 17 against pathogenic bacteria (Staphylococcus aureus ATCC 43300, Shigella flexneri NR 518, Klebsiella pneumoniae 700603, Escherichia coli 25922), performed using broth microdilution method results show that, not active (MIC > 1000 ?g/mL) while weakly or ? 500 strains. Furthermore, chemophenetic relationships significances discussed.