[Untitled]

The interactions of the hydrobromides of (R)- and (S)-alanine-N-methylanilides (1) with 24-, 27- and 36-membered ring pseudopeptides (H-24, H-27 and H-36, respectively) derived from glycine and (2S,3′ S)-4-methyl-2-(2′-oxo-3′-isobutyl-1′-piperazinyl)pentanoic acid were studied by means of 1H and 13C NMR measurements in CDCl3. It was found from these results that H-24 and H-27 distinguished (R)- and (S)-isomers of 1, while H-36 did not entirely. Moreover, the enantioface-differentiating abilities of these cyclic peptides were investigated by means of 1H NMR measurements in CDCI3 using (R)- and (S)-1-phenylethylammonium and (R)- and (S)-p-methoxy-1-phenylethylammonium bromides as the substrates, showing that the enantio-selectivity of H-36 is superior to those of H-24 and H-27. Also, the chiral recognition ability of H-24 for the hydrochlorides of (R)- and (S)-alanine (Ala), -leucine (Leu), -methionine (Met), -phenylalanine (Phe), -proline (Pro) and -valine (Val) methyl esters were examined by 1H and 13C NMR measurements in CDCl3. Among these hydrochlorides, HCl · PheOCH3 was distinguished more effectively with H-24.