A dicarba analogue of insulin comprising an A-chain and a B-chain or fragments, salts, solvates, derivatives, isomers or tautomers of the A-chain, the B-chain or both, provided that the dicarba analogue is not [A7,B7-(2,7-diaminosuberoyl]-des-(B26-B30)-insulin B25-amide.
in protein structures nucleating type I β-turns. By bridging the amino acid side chain in position i with a nitrogen substituent in position i+2 by ring-closing olefin metathesis (RCM), peptide mimetics of type 1 could be developed. NMR based conformational investigations indicated a stable intramolecular H-bond constraining a U-turn conformation that was predicted to simulate a type I β-turn.