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

The chemical study of Rumex abyssinicus Jacp (Polygonaceae) led to the isolation of a new ceramide named (R)-2'-hydroxy-N-[(2S,3S,4R,16E)-1,3,4-trihy-droxyhexacos-16-en-2-yl]hexadecanamide (rumexamide) (1) together with sixteen known compounds: bis-(2-ethylhexyl) phthalate ( 2), chrysophanol (3), physcion bacterial activities of extracts (MeOH, n-BuOH and EtOAc), as well as compounds 9, 11, 12, 15 + 16 and 17 against pathogenic bacteria (Staphylococcus aureus ATCC 43300, Shigella flexneri NR 518, Klebsiella pneumoniae ATCC 700603, Escherichia coli ATCC 25922), were performed using the broth microdilution method and the results show that, extracts were not active (MIC > 1000 µg/mL) while compounds were weakly or not active (MIC ≥ 500 µg/mL) against all bacteria strains. Furthermore, the chemophenetic relationships of the isolated compounds and their significances were discussed.