Interaction between chlorophyll a and violaxanthin in different steric conformations: Model studies in monomolecular layers

摘要: Monomolecular layers of pure chlorophyll a (Chl a), violaxanthin in the conformation all-trans, 9-cis, 13-cis and two-component monomolecular formed with Chl all isomers violaxanthin, at stoichiometric ratio 1:1, were compressed argon–water interface. The specific molecular areas determined on basis isotherms compression. compression a–violaxanthin-all trans monolayers correspond well to theoretical ones, calculated additivity rule. conformations 9-cis are shifted towards higher respect experimental indicating interaction between components system. Monolayers also deposited solid support by means Langmuir–Blodgett technique subjected spectroscopic studies: quartz lamella case electronic absorption fluorescence spectroscopy ZnSe crystal Fourier Transform Infrared Spectroscopy (FTIR). comparison excitation spectra enabled make calculation rate energy transfer from a. Efficiency carotenoid was 32% 21% 15% for 13-cis. Such findings suggest structural role an accessory all-trans photosynthetic apparatus. analysis FTIR reveals cis via hydroxyl groups xanthophylls located C3 C3′ positions.