Characterization of fucoxanthin molecular aggregates by resonanceRaman spectroscopy

摘要

Fucoxanthin (Fx) is one of the carotenoids that is characteristic of brown algae,like Mozukuand Konbu,and it is a photosynthetic pigment of the light-harvesting antenna called Fx-chlorophyll a/c binding protein complex (FCP).Recently,by the X-ray crystal structureanalysis of FCP,it was revealed that Fx is bound to FCP with aggregated form1.Molecularaggregates of carotenoids are classified into H-and J-types2.These two types of aggregatesare easily confirmed by their optical absorption spectra.Comparing to the spectrum ofmonomer,the absorption band of H-type and J-type should show blue-and red-shift,respectively.In this study,we prepared a molecular aggregate with all-trans Fx byreprecipitation method3 and measured its steady-state absorption and resonance Raman spectra.With these spectroscopies we can investigate the relationship between structure andphotophysical properties of Fx molecular aggregates.