Linear Stereo-co-pligopeptides with Alternating D- and L-Residues. I. Synthesis and Mass Spectrometric Behavior of the Members of a Series with Valin Residues

Article abstract of DOI:10.1002/hlca.19800630726

The synthesis of the protected stereo-co-oligopeptides with alternating D- and L-valine residues Boc-(D-Val)m-(L-Val-D-Val)n-OMe (m = 0; n = 1,2,3,4,6,8, and M = 1; n = 1,2,3,4) is described.The co-oligopeptides up to the nonapeptide (m = 1; n = 4) have been prepared in a stepwise fashion.The dodecapeptide (m = 0; n = 6) and the hexadecapeptide (m = 0; n = 8) have been prepared by condensation of smaller peptides, and the criteria used for assessing their stereochemical purity are discussed.Preliminary characterization data are presented.Even the co-oligopeptides with six or more residues, up to the dodecapeptide included, have given EI/MS. showing the molecular ion peak.The possible reasons for this uncommon behavior are examined.