V. Magafa et al., Spectral analysis of a series of partially protected and deprotected tetrapeptides, analogues of AS-I phytotoxin, AMINO ACIDS, 16(3-4), 1999, pp. 403-413
A series of six tetrapeptides, analogues of AS-I phytotoxin, pathogenic to
sunflower, have been synthesized either in solution and/or by solid phase m
ethods and have been tested for phytotoxic activity in various plants and c
ytotoxic activity in three cancer cell lines. These peptides were identifie
d as model compounds by fast atom bombardment (FAB), plasma desorption (PD)
, electrospray ionization (ESI) mass spectrometry and by H-1, H-1-H-1, C-13
and H-1-C-13 NMR. The data presented show that in protected tetrapeptides
the molecular ion was easily identified whereas some difficulties appeared
with the fully deprotected peptides. NMR spectra are given.