Coumarins from Cicuta virosa and their modulating effects on multidrug-resistant (MDR) tumors

A new dimeric coumarin, diarchangelicin A (1), together with 10 known coumarins, were isolated from the aerial parts of Cicuta virosa L. and their structures were elucidated by spectroscopic methods. In addition, the known compounds were evaluated for multidrug resistance reversing activity by using doxorubicin-resistant K562/A02 cells. Compounds 2 and 7 were endowed with remarkable MDR reversing effects. Crown Copyright (C) 2010 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.