Inhibition of MMP-2 secretion from brain tumor cells suggests chemopreventive properties of a furanocoumarin glycoside and of chalcones isolated from the twigs of Dorstenia turbinata

A furanocournarin glycoside new named turbinatocoumarin (1) was isolated from the twigs of Dorstenia turbinata. The structure of turbinatocoumarin (1) was assigned as 5-methoxy-3-[3-(beta-glucopyranosyloxy)-2-hydroxy-3-methylbutyl]psoralen by means of spectroscopic analysis. Known compounds have also been isolated from this genus and identified as (2'S, 3'R)-3'-hydroxymarmesin (2), 5-methoxy-3-(3-methyl-2,3-dihydroxybutyl)psoraten (3), psoralen (4), kanzonol C (5) which was isolated for the first time from this genus, 4-hydroxylonchocarpin (6), umbelliferone, 4-hydroxy-3-methoxybenzaldehyde and 4-methoxyphenol. As part of our continuing search for potential naturally-occurring antitumor drug candidates, the inhibition of matrix metalloproteinase (MMP)-2 secretion from brain tumor-derived glioblastorna cells by the isolated compounds 1, 3, 5, and 6 was evaluated by zymography and compared to the documented naturally-occurring MMP secretion inhibitors chlorogenic acid (CHL) and epigallocatechin-3-gallate (EGCg). Among the compounds tested, the inhibiting MMP secretion concentrations ranged from 0.025 to 250 mu M with up to 80% inhibition. The inhibitory activities of compounds 5 and 6 were found comparable to the common reference compounds CHL and EGCg. This suggests that alternate sources can be explored and exploited for the availability of chemopreventive molecules. (c) 2006 Elsevier Ltd. All rights reserved.