Dynamics and Photophysics of Molecular Excited States. A Theoretical Study of Curcumin in Solvents.

• Grant number: 13/01871-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2013
• End date: April 30, 2015
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Sylvio Roberto Accioly Canuto
• Grantee: Tárcius Nascimento Ramos
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This project focuses on the properties of the excited states of an important molecule with potential therapeutic importance. Curcumin, commonly known as turmeric or saffron from India, is a pigment widely used as an aromatic stimulant and spice of wide use and that produces saffron. However, more recently various medicinal properties have been attributed to dimethoxy curcumin. Among these pharmacological activities, such as antioxidant and antitumoral activities, have attracted more interest. Apparently, their biological properties are enhanced with the absorption of electromagnetic radiation in the visible-ultraviolet region. This molecule has a strong absorption in the region of 400 nm, with increasingly interest. However its major experimental characteristic is the large Stokes shift, that is, the difference in absorption and emission frequency. While the absorption spectrum does not show a strong dependence with the solvent, the fluorescence spectrum is intriguing and very dependent on the solvent medium. In large part this is due to the possibility of tautomeric transformations. The change keto-enol must be linked to the possibility of intermolecular and intramolecular hydrogen bonds. In the second case, the solvent plays an essential role. However, even in low polarity solvents such as cyclohexane, the Stokes shift is of 3500 cm-1. This subject is the main theme of this project.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

RAMOS, Tárcius Nascimento. Solvent Effects on Absorption and Emission Spectra of Dimethoxy Curcumin. 2015. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Física (IF/SBI) São Paulo.