The anti-inflammatory mechanism of a new skeleton alkaloid isolated from Portulaca oleracea L.

A new skeleton alkaloid was isolated from Portulaca oleracea L., which was identified as ethyl (2Z,4E,6E)-3-amino-7-(4-amino-6-ethyl-3-glycyl-5-methylpyridin-2-yl)-2-methylocta-2,4,6-trienoate, trivial named, olerapyridin and the structure was clarified through IR, UV, 1D and 2D NMR as well as UHPLC-ESI-Q-TOF/MS methods. Moreover, the bioactivities of anti-inflammation of the compound were investigated via testing RAW 264.7 macrophage cell stimulated by lipopolysaccharide. The results showed that olerapyridin at 5 μM remarkably downregulated the levels of inflammatory mediators, including IL-1β, the proteins expression levels of iNOS and the mRNA expression levels of COX-2, Additionally, at 15 μM, olerapyridin effectively reduced the levels of NO and TNF-a, as well as the proteins expression levels of COX-2 and mRNA expression levels of iNOS.