Absorption spectra lutein

All lutl alleles are recessive mutations (Fig. 3 A) that accumulate an additional carotenoid with an HPLC retention time and UV/visible absorption spectrum characteristic of a monohydroxy / , e-carotenoid (an a-carotene derived xanthophyll). The identification of the accumulating compound as zeinoxanthin ()3,e-caroten-3-ol) was confirmed by mass spectrometry (Pogson et al., 1996). The only difference between lutein and zeinoxanthin is the presence of an hydroxyl group on carbon 3 of the -ring in lutein. The decrease in lutein and its partial replacement by its immediate precursor, zeinoxanthin, defines lutl as a mutation... 

The gradual addition of water to an acetone solution of lutein causes marked changes in the structure of the absorption spectrum (Fig.4). In the first step only a short-wavelength absorbing form with one maximum is formed. The LWAF appears in the second step. It may then be concluded that the crystalline lutein and presumably some other xanthophylls are accompanied by non-crystalline forms of the pigments. 

Fig. 6. Comparison of different action-and absorption spectra of (1) lactat oxidase1 1U, (2) 0-cis carotene183), (3) ft-trans carotene183), (4) lutein in ethanol/ water76). (5) same action spectrum as in Fig. 3 5...

The fluorescence emission spectrum of Codium LHC-II was maximal at 681 nm irrespective of whether the fluorescence was excited at 436 nm (Chi a), 468 nm (Chi b) or 510 and 540 nm (siphonaxanthin and siponein) (Fig. 3b) demonstrating that all pigments are integral components of the complex. Moreover, the fluorescence emission spectrum of Codium LHC-II is identical with that of spinach LHC-II which is a lutein-Chl a/b-protein whose Chi a/b ratio is 1.2 (Fig. 3b). However, there is a dramatic difference in the excitation spectra of Codium LHC-II and spinach LHC-II (not shown) both of which resemble their respective absorption spectra (Fig. 3b). 

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