Chemistry Carotenoid Radicals Complexehb: Chemistry of Carotenoid Radicals and Complexes

Carotenoids are indispensable molecules for life. They are present everywhere in plants, algae and bacteria, whom they protect against free radicals and oxidative stress. Through consumption of fruits, vegetables and carotenoid-containing fish, they are introduced into the human body and, similarly, protect it. There are thus numerous health benefits associated with the consumption of carotenoids. Being antioxidants they are prone to oxidation themselves, easily forming radicals. In this book we will introduce the chemistry of carotenoid radicals, and additionally present studies on special carotenoid complexes.The physisorption, electron and proton transfer processes that occur when carotenoids are adsorbed on solid artificial matrices or dissolved in aqueous solution have been elucidated, and similar reactions have been predicted in plants. We will provide instructive procedures for various measurement techniques on carotenoid radicals and complexes (optical, electrochemical, electron paramagnetic resonance, density functional theory), and analyze examples. Inclusion complexes of carotenoids with different bio-delivery systems are discussed in a final application chapter. Cover Half Title Chemistry of Carotenoid Radicals and Complexes Copyright Preface About the Authors Contents 1. Introduction References 2. Electrochemical Studies of Carotenoids in Solution References 3. Density Functional Theory Molecular Orbital Calculations 3.1 DFT Calculations of β-Carotene 3.2 Hyperfine Coupling Constants for β-Carotene 3.3 Comparison of Simulated CW ENDOR Spectrum of β-Carotene Radicals to the Experimental Spectrum 3.4 Calculations for Proton Loss at C4(4′) Methylene Position of β-Carotene Radical Cation 3.5 DFT Calculations for Other Carotenoid Radicals 3.6 Conclusions References 4. Electron Paramagnetic Resonance Spectroscopy Measurements 4.1 EPR of Electrochemically Formed Carotenoid Radical Cations 4.2 EPR of Chemically Formed Carotenoid Radical Cations 4.3 Simultaneous Electrochemical and EPR (SEEPR) Measurements 4.4 Continuous Wave Electron Nuclear Double Resonance (CW ENDOR) to Detect β-methyl Protons 4.5 Time-resolved EPR Measurements 4.6 Photoinduced Electron Transfer in Frozen Solutions 4.7 High-frequency/high-field EPR for g-tensor Resolution 4.8 High-frequency/high-field EPR Measurements of Metal Centers 4.9 HFEPR: Effect of Distant Metals on g-tensor 4.10 EPR Studies on Solid Supports 4.11 EPR Spin Trapping of Carotenoids 4.12 EPR Studies of Carotenoid Complexes 4.13 Electron Spin-Echo Envelope Modulation 4.14 Pulsed EPR Relaxation Enhancement Measurements 4.15 α-Protons from HYSCORE Analysis of Powder Spectra 4.16 Pulsed ENDOR: Davies and Mims ENDOR to Detect β-proton Hyperfine Couplings 4.17 DFT Calculations used to Interpret ENDOR Spectra References 5. Carotenoid Complexes 5.1 Carotenoid Complexes with Cyclodextrins 5.2 Carotenoid Complexes with Glycyrrhizic Acid 5.3 Carotenoid Complexes with Arabinogalactan References 6. Photoprotection by Carotenoid Radicals References 7. Carotenoid Analysis Sources Index "This book introduces the chemistry of carotenoid radicals and additionally present studies on special carotenoid complexes, which sets it apart from most carotenoid books which focus on neutral carotenoid species. The authors provide instructive procedures for various characterization techniques on carotenoid radicals and complexes (optical, electrochemical, electron paramagnetic resonance, density functional theory), and analyze examples. Inclusion complexes of carotenoids with different bio-delivery systems are discussed in a final application chapter"