A series of derivatives of 5-(aminomethyl)-8-methoxypsoralens, 8-[(3-aminopropyl) oxy] psoralens, and 5-[[[3-(tri-methylammonio) propyl] oxy] methyl]-8-methoxypsoralen has been synthesized and their potential as PUVA reagents examined. While the DNA association constants of selected psoralens were found to be 106-1@ L mol-', corresponding to efficient binding, flow linear dichroism studies indicated that only the 8-substituted psoralens bind ...