Two new prenylated coumarins from roots of Zanthoxylum nitidum

Two new prenylated coumarins, 3'-hydroxytoddanone (1), and isotoddalolactone (2), along with four known analogues (3-6) were isolated from the roots of Zanthoxylum nitidum. Their chemical structures were elucidated based on extensive spectroscopic interpretation and HR-ESI-MS analysis. The absolute configuration of compound 2 was determined by comparing experimental ECD spectrum with that calculated by the time-dependent density functional theory (TDDFT) method. Compounds 4-6 were isolated from the Zanthoxylum genus for the first time. The two new compounds were tested for antiproliferative activities in vitro on the HL-60, K562 and THP-1 cell lines. Compounds 1 and 2 exhibited moderate cell growth inhibitory activities in vitro against human leukemic HL-60 cell lines, with IC50 values of 32.64 and 33.15 mu M, respectively.