Synthesis, Singlet Oxygen Photogeneration and DNA Photocleavage of Porphyrins with Nitrogen Heterocycle Tails

Eight novel compounds were prepared by reaction of 5-(bromo- propoxyphenyl)-10,15,20-triphenylporphyrin with oxazole thiols, 1,3,4-oxadiazole thiols and 1,3,4-thiadiazole thiols, and their structures confirmed by UV-vis, IR, (1)H-NMR, MS and elemental analysis. The assessment of indirectly measured (1)O(2) production rates against 5,10,15,20-tetraphenyl porphyrin (H(2)TPP) were described and the relative singlet oxygen production yields were: porphyrin 5 > porphyrins 1, 3, 4, 6-8, H(2)TPP > porphyrin 2. Porphyrin 4 and porphyrin 7 showed substantial photocleavage activities toward DNA, with over 75% cleavage observed at 40 µM. It suggested that these those porphyrins with nitrogen heterocycle tails are potential photosensitive agents.