Abstract
The phytochemical investigation of the water extract of Arum palaestinum led to the isolation of three compounds identified as isoorientin (luteolin 6-C-beta-D-glucopyranoside), vitexin (apigenin 8-C-beta-Dglucopyranoside), and vicenin II (apigenin 6,8-di-C-beta-D-glucopyranoside) as well as two new diketopiperazines (DKP), namely 3-hydroxypiperazine-2,5-dione (1) and piperazine-2,5-dione (2). The chemical structures of the isolated compounds were established by spectroscopic methods including IR, MS, and NMR. The new diketopiperazine (1) exhibited mild cytotoxic activity against human multidrug-resistant cell line MES-SA/DX5 with ED50 3.44 mu M.