title: The diketopiperazine-fused tetrahydro-β-carboline scaffold as a model peptidomimetic with an unusual α-turn secondary structure.
abstract: Aiming at restricting the conformational freedom of tryptophan-containing peptide ligands, we designed a THBC (tetrahydro-β-carboline)-DKP (diketopiperazine)-based peptidomimetic scaffold capable of arranging in an unusual α-turn conformation. The synthesis is based on a diastereoselective Pictet-Spengler condensation to give the THBC core, followed by an intramolecular lactamization to complete the tetracyclic THBC-DKP fused ring system. The presence of conformers bearing the intramolecular thirteen-membered hydrogen bond that characterizes the α-turn structure is confirmed by (1)H NMR conformational studies. To the best of our knowledge, this scaffold represents one of the rare examples of a designed constrained α-turn mimic.
authors: Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano, Italy.
authors: Francesco
authors: F
authors: Airaghi
authors: Andrea
authors: A
authors: Fiorati
authors: Giordano
authors: G
authors: Lesma
authors: Manuele
authors: M
authors: Musolino
authors: Alessandro
authors: A
authors: Sacchetti
authors: Alessandra
authors: A
authors: Silvani
keywords: conformational analysis; diketopiperazine; peptidomimetics; tetrahydro-β-carboline; α-turn
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