Pyrido (3,4', 4,5) furo (3,2-g) coumarins or pyrido (3,4-h) psoralens having formula I ##STR1## wherein R is a hydrogen radical or a lower alkyl group having from 1 to 4 carbon atoms and R" is a methyl group or a methoxy group. These compounds are photobiologically active and are useful or medicinals and pharmaceutical compositions in association with ultraviolet radiation for treating skin diseases and as cosmetic compositions for skin pigmentation.

Monofunctional psoralen derivatives having the general formula ##STR1## wherein R represents a hydrogen atom, a lower alkyl group having from 1 to 4 atoms, preferably a methyl radical, or a lower alkoxy radical having from 1 to 4 carbon atoms, preferably a methoxy radical are described. The derivatives are photobiologically active and are useful in photochemical therapy and in cosmetics.

The present invention provides novel furocoumarinsufonamide derivatives having the formula ##STR1## wherein R.sub.1, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently H or lower alkyl; m, n and p are independently 2, 3, 4, 5 or 6; A is NR.sub.4 (CH.sub.2).sub.P NR.sub.5, NR.sub.6, O or S; R.sub.2 is independently H, lower alkyl or a moiety of the formula ##STR2## useful for inhibiting protein kinase C and treating conditions related to, or affected by inhibition of protein kinase C, particularly cancer tumors, inflammatory disease, reperfusion injury, and cardiac dysfunctions related to reperfusion injury.

Systems and methods for determining an effective amount of light energy to deliver to fluids, particularly fluids having target and non-target materials. The systems and methods specifically relate to phototherapy and photopheresis systems where an effective amount of light energy is desired to be delivered to targets in biological fluids.