Main constituents from the seeds of Vietnamese Cnidium monnieri and cytotoxic activity.

From the ethyl acetate extract of the seeds of Vietnamese Cnidium monnieri L., three coumarins, osthole (1), xanthotoxin (2), imperatorin (3) and a sterol, daucosterol (4) have been purified. Their structures were elucidated by spectroscopic analysis. Furthermore, 8-(3-hidroxy-3-methylbutyl)-7-methoxycoumarin (5) was synthesised from osthole (1) with a good yield (80%). In addition, compound 1 and its synthesis product (5) show moderate and non-selective cytotoxic activities against four cancer cells, KB (a human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma) and HepG2 (hepatocellular carcinoma).