Conformational studies of free and Li+ complexed jasplakinolide, a cyclic depsipeptide from the Fijian marine sponge Jaspis splendens

Abstract

The complexation of Li⁺ to jasplakinolide, a marine sponge derived cyclic depsipeptide showed preferential binding to two out of four carbonyl oxygens (C-10, C-14) and the electrons of the aromatic system of the β-tyrosine amino acid residue. This is in contrast to previous results obtained by others who proposed complexation to three out of four available carbonyl oxygens (C-1, C-10, C-14). The structure of the complex in CD₃CN was determined by NOE restrained molecular dynamic calculations. Structures of the uncomplexed jasplakinolide were calculated in CDCl₃ and CD₃CN for comparison.