Psoralen compound compositions are synthesized which have primaryamino substitutions on the 3-, 4-, 5-, and 8-positions of the psoralen, which yet permit their binding to nucleic acid of pathogens. Reaction conditions that photoactivate these psoralens result in the inactivation of pathogens which contain nucleic acid. The compounds show similar activity in test systems to 4′ and 5′ derivatives of psoralen useful for inactivation of pathogens in blood products. In addition to the psoralen compositions, the invention contemplates such inactivating methods using the new psoralens.