Fluorescence of zeaxanthin and violaxanthin in aggregated forms

✍ Scribed by Wieslaw I. Gruszecki; Bogumil Zelent; Roger M. Leblanc

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 510 KB
• Volume: 171
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(90)85264-d

✦ Synopsis

The fluorescence emission, the absorption, and the fluorescence excitation spectra of zeaxanthin (Z) and violaxanthin (V) aggregates formed in a water-ethanol solvent system have been measured. Fluorescence quantum yield for zeaxanthin and violaxanthin are: &Z)=4.3~10-" and &V)=1.7~ IO-'. The fluorescence lifetimes are TV= 1.06+0.07 ns and +(V) =0.90f 0.10 ns. The calculated natural radiative lifetimes, r'(Z) =2.6X 10e6 s and r"(V) =5.3x lo-' s correspond well to the literature values estimated for 'A; state of p-carotene by indirect measurements. The energy of the 'A: state of the carotenoid aggregates has been measured as 17860 cm-'. The fluorescence of these carotenoid aggregates is related to the radiative deactivation of both the 'B, electronic singlet state and the symmetrically forbidden lowest excited electronic singlet state 'A:.