Cytotoxic isoquinoline alkaloids from the roots of .

Phytochemical investigation on the 70% EtOH extract of the roots of DC. resulted in the isolation of three new isoquinoline alkaloids, 5,6,7,12-tetramethoxy-2-methyl-13-hydroxy-11-(4'-methoxycarbonylphenoxy)benzylisoquinoline (), 5,6,7,12-tetramethoxy-2-methyl-13-hydroxy-11-(4'-carbonylphenoxy) benzylisoquinoline (), and 3-methoxy-10--acetylprodensiflorin B (). The new structures were elucidated by using spectroscopic data (NMR, IR, UV, and MS). The isolated alkaloids were tested for cytotoxic potentials against six human lung cancer cell lines (H460, H23, HTB-58, A549, H441, and H2170). As a result, alkaloids and exhibited significant cytotoxic activities against all the tested tumor cell lines with IC values less than 20 μM.