53121-25-8Relevant academic research and scientific papers
Synthetic control of retinal photochemistry and photophysics in solution
Bassolino, Giovanni,Sovdat, Tina,Liebel, Matz,Schnedermann, Christoph,Odell, Barbara,Claridge, Timothy D.W.,Kukura, Philipp,Fletcher, Stephen P.
, p. 2650 - 2658 (2014/03/21)
Understanding how molecular structure and environment control energy flow in molecules is a requirement for the efficient design of tailor-made photochemistry. Here, we investigate the tunability of the photochemical and photophysical properties of the retinal-protonated Schiff base chromophore in solution. Replacing the n-butylamine Schiff base normally chosen to mimic the saturated linkage found in nature by aromatic amines results in the reproduction of the opsin shift and complete suppression of all isomerization channels. Modification of retinal by directed addition or removal of backbone substituents tunes the overall photoisomerization yield from 0 to 0.55 and the excited state lifetime from 0.4 to 7 ps and activates previously inaccessible reaction channels to form 7-cis and 13-cis products. We observed a clear correlation between the presence of polarizable backbone substituents and photochemical reactivity. Structural changes that increase reaction speed were found to decrease quantum yields, and vice versa, so that excited state lifetime and efficiency are inversely correlated in contrast to the trends observed when comparing retinal photochemistry in protein and solution environments. Our results suggest a simple model where backbone modifications and Schiff base substituents control barrier heights on the excited-state potential energy surface and therefore determine speed, product distribution, and overall yield of the photochemical process.
Simple and efficient preparation of [10,20-13C2]- and [10-CH3,13-13C2]-10-methylretinal: Introduction of substituents at the 2-position of 2,3-unsaturated nitriles
Verdegem,Monnee,Lugtenburg
, p. 1269 - 1282 (2007/10/03)
In this paper, we present the synthesis of [10,20-13C2]-10-methylretinal and [10-CH3,13-13C2]-10-methylretinal, two doubly 13C-labeled chemically modified retinals that have been recently used to study the structural and functional details behind the photocascade of bovine rhodopsin (Verdegem et al. Biochemistry 1999, 38, 11316; de Lange et al. Biochemistry 1998, 37, 1411). To obtain both doubly 13C-labeled compounds, we developed a novel synthetic method to directly and regiospecifically introduce a methyl substituent on the 2-position of 3-methyl-5-(2′,6′,6′-trimethyl-1′ -cyclohexen-1′-yl)-2,4-pentadienenitrile. Encouraged by these results, we investigated the scope of this novel reaction by developing a general method for the introduction of a variety of substituents to the 2-position of 3-methyl-2,3-unsaturated nitriles, paving the way for simple and efficient synthesis of a wide variety of 10-, 14-, and 10,14-substituted chemically modified retinals, and other biologically important compounds.
Retinoids and Carotenoids, V.- Synthesis of Modified Retinals
Bestmann, Hans Juergen,Ermann, Peter,Rueppel, Hartmann,Sperling, Walter
, p. 479 - 498 (2007/10/02)
The syntheses of 13-demethyl-13-ethyl-, 13-demethyl-13-propyl-, 13-demethyl-, 13-demethyl-14-methyl-, and 14-methylretinal are described.The UV spectra of some geometric isomers of these compounds are discussed.
Photochemistry of Linear Polyenes Related to Vitamin A. 13-Demethylretinal and 14-Methylretinal
Waddell, Walter H.,West, John L.
, p. 134 - 139 (2007/10/02)
The photochemistry of all-trans-13-demethylretinal (2) and all-trans-14-methylretinal (3) is examined in nonpolar and polar solvents.Upon extended irradiation into the first adsorption band, a photoequilibrium mixture is established that contains a number of isomeric photoproducts.High pressure liquid chromatographic methods are employed to isolate and purify each reaction product, and their adsorption spectral and photochemical properties are examined.Primary photoproducts and quantum yields (ψPI of trans -> cis or cis -> trans photoisomerization for all-trans-, 7-cis-, 9-cis-, and 11-cis-13- demethylretinal and all-trans-, 9-cis-, 11-cis-, and 13-cis-14-methylretinal are determined in a nonpolar solvent.The variation in ψPI and the relative photoproduct ratios of the isomers of 13-demethylretinal and 14-methylretinal differ from those of the corresponding isomers of retinal.The differences in quantum yields, primary products, and their relative ratios are analyzed in terms of the structural changes resulting from incorporation or removal of the alkyl substituent of the C-13-C-14 carbon-carbon double bond.
