Antiproliferative constituents from Aphananthe aspera leaves

Extensive screening for the antiproliferative activity of different compounds found in trees was performed by extracting the leaves of Aphananthe aspera (Thunb.) Planch and then using chromatographic separation to afford 2 new compounds, (2S, 4R)-2-carboxy-4-(E)-p-caffeoyl-1-methyl-hydroxyproline (1) and 5-O-caffeoyl quinic acid-(7'R, 8'S, 7''E)-3', 4', 3''-dihydroxy-4'',7'-epoxy-8',5''-neolign-7'-ene-9-carboxyl (2). In addition, 6 known compounds were discovered from the leaves of this plant. The structural determination of all compounds, including their absolute configurations, was established by UV, IR, HRESIMS, 1D and 2D NMR, and CD spectroscopy. The novel compound 1 showed strong antiproliferative activity against human breast adenocarcinoma cells MCF-7 and MDA-MB-231.