A new alkaloid from Portulaca oleracea L. and its antiacetylcholinesterase activity.

A new alkaloid, (10 E , 12 E )-9-ureidooctadeca-10, 12-dienoic acid, named oleraurea (1) and 10 known compounds, p -hydroxybenzaldehyde (2) , p -hydroxybenzoic acid (3) , p -hydroxyacetophenone (4) , benzamide (5) , ( E) - p -coumaramide (6) , ( E )-ferulamide (7) , soyalkaloid A (8) , β -carboline-3-carboxylic acid (9) , 2, 3, 4, 9-tetrahydro- 1H -pyrido [3, 4- b ] indole-3-carboxylic acid (10) , (1 S , 3 S )-1-methyl-1, 2, 3, 4-tetrahydro- β -carboline-3-carboxylic acid (11) were obtained from Portulaca oleracea L., in which, compounds 4 , 5 , 8-11 were isolated from the plant for the first time. The structure of the compound 1 was identified using spectroscopic methods including 1D and 2D NMR, HR-ESI-TOF-MS. The compounds 1, 5-11 presented anticholinesterase activities, but the P. oleracea extract (POE) presented very low anticholinesterase activity.