Research Professor Emeritus
- Postdoctoral Fellow, Varian, 1966-67
- Postdoctoral Fellow, Carnegie Mellon University, 1967-1968
- PhD, Michigan State University, 1966
- BA, St. Olaf College, 1962
The role of carotenoids in photosynthesis, free radicals studied by electron spin resonance and electron-nuclear double resonance.
Structure and reaction mechanism of free radicals in organic single crystals, glasses, powders, films, and solution using electron spin resonance, electron-nuclear double resonance, electron-electron double resonance and electron spin echo methods. Radiation chemistry, coal chemistry, conducting polymers, photochemistry, electrochemistry, archival lifetime of flexible magnetic recording media, and the role of carotenoids in photosynthesis. Description of Research: For a number of years, electron-electron double resonance (ELDOR), electron-nuclear double resonance (ENDOR) and electron paramagnetic resonance (EPR) investigations have been carried out to establish free radical reaction mechanisms in irradiated media as a function of host lattice. In the past we have been investigating the molecular and free radical processes that occur in the formation of conducting polymers. Photosynthesis related studies are of current interest. Simultaneous electrochemical and EPR studies of carotenoid cation radicals and dications have shown the two-electron transfer character of carotenoids. In addition we are interested in understanding the energy transfer between carotenoids and chlorophyll, of value in the development of solar converters based on photosynthesis as well as the structure of carotenoid excited states, radical cations and triplet states.
“Carotenoids: Importance in Daily Life – Insight Gained from EPR and ENDOR,” A. Ligia Focsan, Nikolay E. Polyakov, and Lowell D. Kispert, Applied Magnetic Resonance, 1 – 20, published online March 2, 2021.
“Antioxidant Activity in Supramolecular Carotenoid Complexes Favored by Nonpolar Environment and Disfavored by Hydrogen Bonding,” Yunlong Gao, A. Ligia Focsan, and Lowell D. Kispert, antioxidants, 9, 625 – 646 (2020).
“Supramolecular Carotenoid Complexes of Enhanced Solubility and Stability – The Way of Bioavailability Improvement,” A. Ligia Focsan, Nikolay E. Polyakov, and Lowell D. Kispert, Molecules, 24, 3947 – 3975 (2019).
“The carotenoid Bixin found to exhibit the highest measured carotenoid oxidation potential to date consistent with its practical protective use in cosmetics, drugs and food,” Sefadzi Tay-Agbozo, Shane Street, and Lowell Kispert, J. Photochem. & Photobio, B: Bio., (186), 1-8 (2018).
“Electrochemical Study of Astaxanthin and Astaxanthin n-Octanoic Monoester and Diester: Tendency to Form Radicals,” A. Ligia Focsan, Shanlin Pan, and Lowell D. Kispert, J. Phys. Chem. B, 2331-2339 (2014).
“Neutral Carotenoid Radicals in Photoprotection of Wild-Type Arabidopsis Thaliana,” Adam Magyar, Michael K. Bowman, Péter Molnár, and L. Kispert, J. Phys. Chem. B, 117 (8), 2239-2246 (2013).
“Enhancement of Photocatalytic Activity of TiO2 Nanoparticles by Water Soluble Complexes of Carotenoids,” Nikolay E. Polyakov, Tatyana V. Leshina, Elizaveta S. Meteleva, Alexander V. Dushkin, Tatyana A. Konovalova, and Lowell D. Kispert, J. Phys. Chem. B, 114, 14200-14204, (2010).
“Formation of Carotenoid Neutral Radicals in Photosystem II,” Y. Gao, K. E. Shinopoulos, C. A. Tracewell, A. L. Focsan, G. W. Brudvig, and L. D. Kispert, J. Phys. Chem. B, 113, 9901-9908 (2009).
“Water Soluble Supramolecular Complexes of -Carotene and Other Carotenoids. In: Beta Carotene: Dietary Sources, Cancer and Cognition. N. E. Polyakov, L. D. Kispert, Eds. By L. Haugen and T. Bjornson, Nova Science Publishers, (2009), pp. 191-230.
“Structure and Properties of 9′-cis Neoxanthin Carotenoid Radicals by Electron Paramagnetic Resonance Measurements and Density Functional Theory Calculations: Present in LHC II”, A. L. Focsan, P. Molnar, J. Deli, and L. D. Kispert, J. Phys. Chem. B, 113, 6087–6096, (2009).
“Pulsed EPR and DFT Characterization of Radicals Produced by Photo-Oxidation of Zeaxanthin and Violaxanthin on Silica-Alumina.” Focsan, A. L.; Bowman, M. K.; Konovalova, T. A.; Molnar, P.; Deli, J.; Dixon, D. A.; Kispert, L. D. J. Phys. Chem. B 112, 1806-1819 (2008).