Validation of a solid-phase-bound steroid scaffold for the synthesis of novel cyclic peptidosteroids.

The current article reports on the synthesis of a new type of cyclic peptidosteroid, in which a bile-acid-based scaffold was used for the conformational restriction of a loop-like peptide. Convergent coupling of two tetrapeptides to the non-peptidic steroidal entity was carried out once in the classical C-to-N and once in the non-classical N-to-C direction. Peptide backbone cyclisation was then carried out, giving rise to a ring size equivalent to approximately 12 amino acids. This type of construct will be used in the development of a peptide vaccine against measles.