engleski

Synthesis and Spectroscopic Evidences of Aminoacid Esters of 4',5'-Isobutyliden-O-protected Pyridoxine

The preparation of ?-aminoacid esters with pyridoxine (B6 vitamin) were investigated. The scope of investigation was the synthesis of the potential "pro drug" substances for the therapy of metabolic disorders that required an increased input of the corresponding essential ?-aminoacid (i.e., cirrhosis, hepatic encephalophaty, liver and renal failure). For this purpose both ?-aminoacid esters from BOC- and Z-N-protected aminoacids (Gly-OH, Ala-OH, Leu-OH and Phe-OH) and 4', 5'- isobutyliden pyridoxine with addition of DCC were synthesized. Chemical structures of obtained esters were determined by IR, one- and two-dimensional, homo- and heteronuclear 1H and 13C NMR correlation spectra (COSY, NOESY, HETCOR and HMBC). BOC-N-protected aminoacids gave better yields in comparing to Z-aminoacids, and the most reactive was BOC-Phe-OH. The use of unprotected pyridoxine, as an alcoholic component, in the same reaction condition with excess of amino acid and DCC (pyridoxine:aminoacid:DCC=1:3:3), gave a mixture of mono-, di- and tri-esters. The removing of protecting group by trifluoroacetic acid, from aminoacid's part of ester, gave and other products of reaction, so the selective removings of protecting group remain for the further investigation.

Amino acid esters; B6 vitamin; isobutylidenpyridoxine; 1D and 2D NMR; 1H and 13C NMR spectroscopy

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