Three novel alkaloids from Portulaca oleracea L. and their anti-inflammatory bioactivities

Three novel alkaloids, identified as (E)-N-((2R)-3-(2,5-dihydroxy-4-((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)phenyl)-2-hydroxypropanoyl)-3-(4-hydroxyphenyl)acrylamide (1), named oleracrylimide A, (E)-N-((2R)-3-(2,5-dihydroxy-4-((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)phenyl)-2-hydroxypropanoyl)-3-(4-hydroxy-3-methoxyphenyl)acrylamide (2), named oleracrylimide B, and (E)-N-((2R)-3-(2,5-dihydroxy-4-((3,4,5-trihydroxy-6-(((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)methyl)tetrahydro-2H-pyran-2-yl)oxy)phenyl)-2-hydroxypropanoyl)-3-(4-hydroxy-3-methoxyphenyl)acrylamide (3), named oleracrylimide C were isolated from Portulaca oleracea L. and the structures of the three novel compounds were determined by 1D and 2D NMR, circular dichroism, and UHPLC-ESI-QTOF/MS spectroscopic methods. Moreover, the bioactivities of anti-inflammation of the three compounds were investigated via testing RAW 264.7 macrophage cell stimulated by Lipopolysaccharide.