Аннотация:An alternative variant of the method for the synthesis of an analogue of natural retinal, in which the trimethylcyclohexene ring of the molecule is replaced by a p-fluorophenyl fragment, has been developed. It has been shown that the proposed scheme for the synthesis of the target all-E-isomer of the target retinoid using C5-phosphonate with a terminal nitrile group under Horner–Emmons reaction conditions is more efficient and gives a higher total yield of the target product than the variant synthesis described earlier. A procedure has been developed for preparation an analogue of microbial proteorhodopsin ESRh from Exiguobacterium sibiricum with a modified chromophore. It was found that, as in the case of bacterioopsin from Halobacterium salinarum, the replacement of the trimethylcyclohexene ring in the natural chromophore by the p-fluorophenyl fragment does not block the possibility of the formation of the artificial pigment F-Phe-ESRh from proteorhodopsin ESRh, which preserves the cycle of photochemical reactions. Certain differences were found in the properties of native recombinant ESRh and its analogue F-Phe-ESRh, including a shift in the absorption maximum to the short-wavelength region, the formation of intermediate M at lower pH values, the presence of “long-lived M”, and a general slowdown in the photocycle. The reduced stability of the resulting proteorhodopsin analog F-Phe-ESRh to prolonged exposure to visible light was also demonstrated.