Isolation of coumarins and ferulate from the roots of Angelica purpuraefolia and the antitumor activity of khellactone

Abstract

A new coumarin, hydroxylomatin (1), was isolated from the CHCl(3)-soluble fraction of the roots of Angelica purpuraefolia, along with one ferulate (2) and three other known coumarins (3-5) including khellactone (3). The structure of hydroxylomatin (1) was determined to be 3'beta,5'-dihydroxy-3',4'-dihydroseselin (1) by spectroscopic means including 2D-NMR. The modified Mosher's method was used to determine the chiral center at C-1 of compound 2. Khellactone (3) is a major compound of the roots of A. purpuraefolia. This study also examined the antitumor activity of khellactone (3) using a LLC mouse lung carcinoma in the BDF-1 mice and a NCI-H460 human lung carcinoma in a human tumor xenograft model in nude mice. This compound (3) inhibited LLC tumor growth with a T/C (mean value of treated group/mean value of control group) value of 12.9% at a dose of 5 mg/kg and 33.2% at a dose of 10 mg/kg, respectively, in a dose-dependent manner. In addition, it suppressed the growth of NCI-H460 tumor cells, accounting for 81.4% at a dose of 10 mg/kg in nude mice.