Abstract
Electron Paramagnetic Resonance (EPR) spectroscopy was employed in the study of the interaction between L-3,4-dihydroxyphenylalanine (L-Dopa) melanin and the cationic porphyrins meso-tetrakis(1-methylpyridinium-4yl)-porphyrin (TMPyP), meso-tetrakis-(1-benzylpyridinium-4-yl)-porphyrin (TBzPyP), and their respectives complexes ZnTMPyP and ZnTBzPyP. By monitoring signal intensities and progressive microwave power saturation it was shown that the interaction increases the equilibrium concentration of free radicals in L-Dopa melanin in the dark. The extent of increase is dependent on the presence of molecular oxygen and on the type of porphyrin. Not all interacting sites available for complexation in L-Dopa melanin are involved in the formation of free radicals. It was also observed that the interaction with porphyrins promotes an increase in the number of photoinduced free radicals in L-Dopa melanin during illumination with visible light.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
