83802-77-1

Novel hybrid vitamin, 3-O-retinoyl-L-ascorbic acid (3a) was conveniently prepared by reaction of sodium L-ascorbate with retinoyl fluoride. The 3-O-acylated structure was confirmed by the comparison of spectral data of its methylated compound with those of 3-O-methyl-2-O-retinoyl-L-ascorbic acid (20) prepared from 5,6-O-isopropylidene-3-O-methyl-L-ascorbic acid. 3-O-Retinoyl-L-ascorbic acid (3a) showed a reducing activity against the stable radical, α,α-diphenyl-β-picrylhydrazyl (DPPH).

The toxic and teratogenic effects caused by the highly biologically active (all-E)-retinoic acid and its derivatives prompted us to synthesize a number of retinoids.We developed synthetic approaches to (all-E)-retinyl-β-D-glucuronide 3, methyl (retinoyl β

In order to obtain a light-stable rhodopsin as a potential candidate for crystallization and structural X-ray analysis, we synthesized and characterized the novel all E-10,20-methanoretinoyl fluoride (2).This retinal analogue has a locked 11-cis configuration, preventing the light-induced 11-cis -> trans isomerization and binds to opsin by a stable peptide bond rather than a Schiff base. 2 reacted with (methylated) bovine opsin, forming a light- and thermo-stable pigment with λmax at 390 nm.Its opsin shift (2500 cm-1) is in the same order of magnitude as that in rhodopsin (2650 cm-1), suggesting that the mechanism for the red shift is not located in the direct vicinity of the chromophore-protein linkage.We also report the first synthesis and characterization of all-E-retinoyl fluoride (10), which failed to give a pigment on reaction with bovine opsin.

This invention relates to the 15-fluoro-retinoid compounds which provide vitamin A activity with reduced liver storage. A preferred compound is retinoyl fluoride.

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