Synthesis and Biological Studies of Some Novel Porphyrin Appended Heterocycles

Abstract

Porphyrins are by far the most commonly used photosensitizers in Photodynamic Therapy for their potential as anticancer agents Upon irradiation with appropriate wavelength porphyrins can produce reactive oxygen species that plays an important role in its cytotoxic effects on tumor tissues They also tend to exhibit absorption in the long wavelength region due to their and#960; extended conjugation and found to be useful in material chemistry Furthermore they can have specific interactions with proteins on cell membranes and thus exhibit specific targeting of cancer cells This thesis explores the synthesis cytotoxicity and photophysical studies of some novel porphyrin heterocycles The investigation described in the thesis mainly consists of four chapters The first chapter provides a detailed review of porphyrins It gives an introduction to the porphyrins followed by their natural source absorption and emission properties and various methods of preparation This chapter also elaborates on porphyrinbased anticancer drugs and their mechanism of action in cancer cells The second chapter describes synthesis photophysical and nuclease activity of some porphyrin heterocycles and it has been divided into three parts Part A Part B and Part C Part A discusses a regioselective synthesis of porphyrin diarylthiazoles via the reactions of alkynylaryliodonium tosylates and porphyrin thioamides Two compounds exhibited significant interactions with ctDNA and showed efficient photonuclease activities Part B discloses a modular synthetic approach to obtain porphyrin appended oxadiazoles Photophysical studies showed that the electronic structure of the porphyrin chromophore is not greatly perturbed by the incorporation of the oxadiazole moiety onto the mesophenyl ring Further mesoporphyrin134oxadiazoles also exhibited photonuclease activity 20 and#956;M in UV and visible light Part C deals with the preparation of Narylaminoporphyrins from the coupling reactions of aminoporphyrins with diaryliodonium salts Synthesized Narylaminoporphyrins were utiliz.