A method of macrocyclization of peptidomimetics is described which comprises substitution of one or more of the backbone amide C═O bonds with a turn-inducing motif. The method is general with enhancements seen across a range of ring sizes (e.g. tri-, tetra-, penta- and hexapeptides). Specifically, a peptidomimetic macrocycle is described comprising a carbonyl bioisosteric turn-inducing element having the structure:






wherein X is a heteroatom; and
wherein R1 to R6 are each independently selected from alkyl, aryl, heteroaryl and H.