Chemical constituents and cytotoxicity from the stem bark of Citrus medica

A new biscoumarin, namely citrumedin-A [6,6′,7,7′-tetramethoxy-3,3′-biscoumarin] (1), together with twenty two known compounds were isolated from the stem bark of Citrus medica L. var. sarcodactylis Swingle. The structure of this new compound was completely elucidated using a combination of 2D NMR techniques (COSY, NOESY, HMQC and HMBC) and HR-EI-MS analyses. The known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literatures. The isolates were also screened their cytotoxicity against Daoy, Hep2, MCF-7 and Hela cell lines. Lonchocarpol A (12) showed marginally cytotoxic activity against those four cancer cell lines.