Ideal reaction conditions were found to promote the "cold" monomethylation of 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin with CH3I, at minute time scale, in the presence of base. The photophysical characterization, cellular uptake and dark cytotoxicity of the resulting monomethylated porphyrin were appraised. Moreover, the syntheses of the corresponding labeled porphyrin, using short-lived carbon-11, prepared in the automated radiolabeling system were efficiently performed. The purification of the labeled product was achieved via preparative HPLC with high radiochemical purity and specific radioactivity. Preliminary studies on the biodistribution of 5,10,15-tris(3-hydroxyphenyl)-20-(3-[11C]methoxyphenyl)porphyrin carried out in a BALB/C normal mouse, using PET imaging, showed that the liver is the main pathway for excretion.

Read More: http://www.worldscientific.com/doi/abs/10.1142/S1088424615500728