title: Prediction of ROA and ECD Related to Conformational Changes of Astaxanthin Enantiomers.
abstract: ECD, ROA, and VCD were used to characterize astaxanthin conformers that differ in their arrangements of the β-ionone ring in respect to the chain. We obtained ECD spectra experimentally, and the ECD, ROA, and VCD spectra of both individual conformers and conformation-averaged mixtures were predicted using quantum-chemical calculations at the CAM-B3LYP level of theory using the PCM solvation model. The chiroptical methods employed (particularly ECD and ROA) were considerably more sensitive to conformational changes of astaxanthin compared to "mono-signed" conventional Raman spectroscopy. Strikingly, conformers that are the same optical isomers (e.g., of 3S,3'S-astxanthin), while geometrically nearly mirror images, exhibited sign-inversed ECD and ROA spectra. The conformational sensitivity of these chiroptical methods makes them a promising tool in the study of carotenoids in the natural environment (for instance, in de novo algal or yeast astaxanthin sources).
authors: Faculty of Chemistry, Jagiellonian University , 3 Ingardena Str., 30-060 Krakow, Poland.|Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University , 14 Bobrzyńskiego Str., 30-348 Krakow, Poland.
authors: Grzegorz
authors: G
authors: Zajac
authors: Faculty of Chemistry, Jagiellonian University , 3 Ingardena Str., 30-060 Krakow, Poland.|Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University , 14 Bobrzyńskiego Str., 30-348 Krakow, Poland.
authors: Agnieszka
authors: A
authors: Kaczor
authors: Faculty of Chemistry, Jagiellonian University , 3 Ingardena Str., 30-060 Krakow, Poland.
authors: Szymon
authors: S
authors: Buda
authors: Faculty of Chemistry, Jagiellonian University , 3 Ingardena Str., 30-060 Krakow, Poland.|Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors: Jacek
authors: J
authors: Młynarski
authors: Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors: Jadwiga
authors: J
authors: Frelek
authors: National Medicines Institute , 30/34 Chełmska Str., 00-725 Warsaw, Poland.|Institute of Nuclear Chemistry and Technology , 16 Dorodna Str., 03-195 Warsaw, Poland.
authors: Jan Cz
authors: JC
authors: Dobrowolski
authors: Faculty of Chemistry, Jagiellonian University , 3 Ingardena Str., 30-060 Krakow, Poland.|Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University , 14 Bobrzyńskiego Str., 30-348 Krakow, Poland.
authors: Małgorzata
authors: M
authors: Baranska
mesh_terms: D002338:Carotenoids / Q000737:chemistry*; D002942:Circular Dichroism; D008968:Molecular Conformation; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013237:Stereoisomerism; D024341:Xanthophylls / Q000737:chemistry
chemical_list: D024341:Xanthophylls; D002338:Carotenoids; C005948:astaxanthine