CAROTENOHEMATOPORPHYRINS AS TUMOR LOCALIZING AND VISUALIZING AGENTS

A new class of molecules consisting of one or more carotenoid polyenes covalently linked to derivatives of naturally occurring heme (exemplified by structures 1-3) have been synthesized for use as tumor localizing, visualizing and diagnostic agents. These carotenohematoporphyrins are desinged to be administered by injection or other means, to localize preferentially in neoplastic tumor tissue, to absorb visible light and theeupon to fluoresce red lig red light that can be detected by eye or by instrumental methods, thus identifying and delineating the tumor tissue. Furthermore, these compounds are designed to quench porphyrin triplet states by triplet-triplet energy transfe transfer to an attached carotenoid. This will prevent formation of singlet oxygen by energy transfer from porphyrin triplet states, and thus prevent tissue damage to healthy tissue caused by the singlet oxygen, or by long-lived