NMR J-based analysis of nitrogen-containing moieties and application to dysithiazolamide, a new polychlorinated dipeptide from Dysidea sp.

The methodology of J-based analysis applied to 1,3-methylcarboamido systems allowed us to deduce the relative configurations of the two leucine-like fragments of a new tetrachloro, amino acid derivative dysithiazolamide, which was isolated from an unidentified sponge of the genus Dysidea. Furthermore, the absolute configuration was also proposed by comparison with analogous systems. (c) 2005 Elsevier Ltd. All rights reserved.