Siamycins I and II, New Anti-HIV-1 Peptides: II. Sequence Analysis and Structure Determination of Siamycin I

We have previously reported on the preparation and initial characterization of the structure and biological activity of siamycins I and II. Here, we report on the novel strategy used to rapidly determine the primary, secondary and preliminary solution structure of siamycin I using a multidisciplinary approach that utilized primarily MS and NMR data. The presence of three internal covalent cross-linkages found in siamycin I made structure analysis by traditional methods difficult, particularly in the N-terminal region.