A novel alkaloid from Portulaca oleracea L. and its anti-inflammatory activity

A novel alkaloid identified as methyl 8,9-dihydroxy-11-oxo-6,11-dihydro-5H-benzo[d]pyrrolo[1,2-a]azepine-3-carboxylate, named portulacatone A (1) with six known compounds Oleracein E (2), 6,7-dihdroxy-3,4-dihydro-2H-isoquinolin-1-one (3), N-trans-p-coumaroytyramine (4), 9H-carbazole (5), isoaspergin (6) and flavoglaucin (7) were obtained from Portulaca oleracea L., while compounds (5-7) were isolated from the plant for the first time. The new structure was identified by using UHPLC-ESI-Q-TOF/MS, 1D, 2D NMR and the others were proved by ¹H-NMR and ¹³C NMR that comparing with previous reports. It was suggested that the portulacatone A (1) can significantly inhibit the inflammatory factor, interleukin-1β (IL-1β) in the RAW 264.7 cells induced by LPS.

Keywords: Portulaca oleracea L.; alkaloid; anti-inflammatory; isolation.