Synthesis of nitroxide containing polyenes: two chemically modified retinals and their interaction with bacterioopsin

Article abstract of DOI:10.1002/recl.19951140906

The synthesis and spectroscopic characterization of two retinal analogues is described, the paramagnetic 3-pyrrolin-1-yloxy analogue 1 and its diamagnetic equivalent, the 3-pyrroline analogue 2.Various aspects of the synthesis of the aminoxy group containing polyenes are discussed.Upon interaction with bacterioopsin, both 1 and 2 are incorporated in the protein and form a system with λ_max 459 nm.Neither of the two bacteriorhodopsin analogues is photoactive.ESR spectroscopy data of the system containing 1 show that the ring part of the chromophore in the protein is rigidly fixed in orientation.