The invention relates to cortistatin analogues and their uses. The compounds of the invention are peptide ligands with potential application in the diagnosis, prevention or therapy of those pathologies where receptors capable of binding to cortistatin, specific or shared with other molecules such as somatostatin and/or ghrelin (GHSR), are expressed, being in addition more stable in serum than cortistatin.

The present disclosure discloses a method for synthesizing an amide and/or a polypeptide using a temporary protected amino acid as an ammonia component. In the present disclosure, a ynamide compound is used as a condensing agent, a low-cost unprotected amino acid is used as the raw material, a silylation reagent is used to temporarily protect the amino acid to perform a condensing reaction, and after the construction of a peptide bond is achieved, a target polypeptide carboxylic acid can be obtained by a simple acid treatment, which can be directly used for the condensation of the next amino acid.