Two new amide alkaloids from Portulaca oleracea L. and their anticholinesterase activities

Two new amide alkaloids, identified as 5,6-dihydroxy-3,4-dihydroisoquinolin-1(2H)-one, named oleraciamide G (1) and (E)-1-(5-hydroxy-6-((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-1H-indol-1-yl)-3-(4-hydroxyphenyl)prop-2-en-1-one, named oleraindole D (2) were obtained from Portulaca oleracea L. Their structures were determined by spectroscopic methods, including the 1 D and 2 D NMR, high-resolution electrospray ionization time-of-flight mass spectrometry. In addition, compounds 1 and 2 presented anticholinesterase activities with IC50 values of 65.71 ± 0.15 μM and 58.78 ± 0.36 μM, respectively.