Metal binding of Lissoclinum patella metabolites.Part 2: Lissoclinamides 9 and 10

摘要

Sutdies on the Thz,Thn and Oxn containing cyclic peptides,lissoclinamides 9(9) and 10(10) isolated from the Indo-Pacific ascidian (seasquirt) Lissoclinum patella have delineated their metal binding selectivity.MS and CD competition studies show that lissoclinamide 10(10) shows selectivity for Cu~(2+) in the presence of an excess of Zn~(2+) whereas lissoclinamide 9(9) is less selective for Cu~(2+).Comparison of the solution state conformations derived from nOe restrained molecular dynamics and additional Monte-Carlo conformational searches suggested binding environments for the Cu~(2+) which confirmed the MS emasruements and suggested a reason for the selectivity in the case of lissoclinamides 9 and 10.