Properties of astaxanthin/Ca2+ complex formation in the deceleration of cis/trans isomerization.
Deceleration of the regioselective cis/trans isomerization of all-trans-astaxanthin (ASTX) in the presence of Ca2+ was shown by HPLC analysis. The NMR and ITC analyses provided evidence for complexation of ASTX with Ca2+ in 1:2 stoichiometry via chelation at both carbonyl and hydroxyl groups. The rotation across torsion omega6 (C5-C6-C7-C8) upon complexation is consistent with the NOE between 7-H and 5-CH3. This study supports the inhibitory effect of ASTX on calcium-induced turbidity of lens crystallins.
Chen
Chien-Sheng
CS
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Wu
Shih-Hsiung
SH
Wu
Ying-Ying
YY
Fang
Jim-Min
JM
Wu
Tzu-Hua
TH
D002118:Calcium / Q000737:chemistry* / Q000494:pharmacology; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D003459:Crystallins / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D015394:Molecular Structure; D013237:Stereoisomerism; D013816:Thermodynamics; D024341:Xanthophylls / Q000097:blood / Q000737:chemistry / Q000494:pharmacology
D003459:Crystallins; D024341:Xanthophylls; C005948:astaxanthine; D002118:Calcium