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Systematic Derivatization of Curcumin and its Effect on Antioxidant Capacity and Action Mechanism. Cyclic Voltammetry and DFT as Tools of Analysis
Author(s) -
BelmontBernal Fernando,
Aguilar Julio César,
Ramos Estrella,
Guadarrama Patricia
Publication year - 2016
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201600992
Subject(s) - chemistry , cyclic voltammetry , fragmentation (computing) , hydrogen atom , molecular orbital , photochemistry , molecule , stereochemistry , computational chemistry , organic chemistry , electrochemistry , electrode , alkyl , computer science , operating system
Eight curcumin derivatives were synthesized by esterification of its phenol groups with first and second generation polyester dendrons (dendronization) or glutaric anhydride (glutarization), in a systematic scheme where mono and disubstitutions were carried out. The dendronization of curcumin (CUR) affects the fragmentation patterns in mass spectra, particularly for the disubstituted OH‐terminated second generation derivative (labeled as 2C2), undergoing the cleavage of one of the aromatic rings. This fact may be related to the antioxidant capacity of 2C2, evaluated following its reaction with superoxide (O 2 •‐ ) by cyclic voltammetry (CV). As opposed to CUR and the rest of its derivatives that react with O 2 •‐ via proton transfer reactions, 2C2 reacts with O 2 •‐ mainly by hydrogen atom transfer. 2C2 radical scavenging activity versus O 2 •‐ is higher than the one observed for CUR. From DFT calculations, independently of the substitution on CUR, the frontier molecular orbitals remain nearly unaltered as compared to CUR. On the other hand, when CUR is dendronized, the electric dipole moment notably changes as a function of the nature of the terminal groups.