Method for inactivating pathogens in blood using photoactivation of 4'-primary amino-substituted psoralens

A method of inactivating pathogens in a composition comprising a blood product, comprising the steps of:

• a) contacting one or more psoralen compounds or salts thereof of formula I, ##STR3## wherein R.sub.1 is --(CH.sub.2).sub.2 --NH.sub.2,
• --(CH.sub.2).sub.w --R.sub.2 --(CH.sub.2).sub.z --NH.sub.2,
• --(CH.sub.2).sub.w --R.sub.2 --(CH.sub.2).sub.x --R.sub.3 --(CH.sub.2).sub.z --NH.sub.2, or
• --(CH.sub.2).sub.w --R.sub.2 --(CH.sub.2).sub.x --R.sub.3 --(CH.sub.2).sub.y --R.sub.4 --(CH.sub.2).sub.z --NH.sub.2 ;
• and R.sub.2, R.sub.3, and R.sub.4 are independently Q or NH.sub.3, and w is a whole number from 1 to 5, x is a whole number from 2 to 5, y is a whole number from 2 to 5, and z is a whole number from 2 to 6;
• R.sub.5, R.sub.6 and R.sub.7 are independently H and (CH.sub.2).sub.v CH.sub.3, and v is a whole number from 0 to 5 in a concentration sufficient to inactivate pathogens upon photoactivation, with a blood product suspected of being contaminated with pathogens;
• and
• b) photoactivating said compound for a duration and at an intensity and a wavelength sufficient to inactivate the pathogens.