LIPIDIC PEPTIDES .7. SYNTHESIS AND STRUCTURE ELUCIDATION OF GAMMA-AMINOBUTYRIC-ACID CONJUGATES WITH LIPIDIC ACIDS, LIPIDIC AMINO-ACIDS AND LIPIDIC PEPTIDES

A series of gamma-aminobutyric acid esters of lipidic acids, lipidic peptides and gamma-aminobutyric acid amides of lipidic alpha-amino acids and oligomers were synthesised. The GABA conjugates with ester linkages (6j-r) were prepared by coupling the lipidic acids and peptide conjugates to the carboxyl terminus of GABA. Two types of GABA conjugates linked by amide bonds were synthesised. This class included compounds 5d-f in which the amino group of the lipidic amino acid is condensed with the carboxyl function of GABA and compounds 7a-b with the carboxyl terminus of the alpha-amino acid coupled to the amino group of GABA. The lipidic amino acid peptide oligomers were varied from 1-3 units, and the alkyl side chains ranged from 5-17 carbon atoms in length in order to impart different lipophilicities to the GABA molecule conjugates.