The photoinduction of DNA cross-links by the furanochromone visnagin

The furanochromone, visnagin, was evaluated for its ability to produce cross-links in DNA in the presence of long-wave UV (UV-A). Three techniques for measuring cross-links were used, viz.: alkaline agarose gel electrophoresis, resistance to S r nuclease, and hydroxyapatite chromatography. The DNA preparations were obtained from cultured mouse cells (3T3-L1), calf thymus, and murine cytomegalovirus (MCMV). In addition the intact virus itself (MCMV) was tested. Visnagin formed cross-links in all four DNA preparations, in UV-A, although not as efficiently as 8-methoxypsoralen. At a concentration of visnagin which gave 99% killing of virus infectivity < 50% of the DNA was cross-linked.