Solid-state structure of cyclic dipeptides: an X-ray and computational study of cis- and trans-diketopiperazines of N-methyl-phenyl­alanine with the thia-pipecolic acids and thia-prolines

ABSTRACT: X-ray and computational study of cis- and trans-diketopiperazines of N-methyl-phenyl­alanine with the thia-pipecolic acids and thia-prolines are presented. The effect of sulfur on the geometry of diketopiperazine ring and amide bond non-planarity is discussed. Ten new crystal structures of cis and trans bicyclic diketopiperazines (DKPs) of thia-pipecolic acid (with sulfur in the β, γ or δ position) or thia-proline (with sulfur in the β or γ position) and N-methyl phenyl­alanine [(NMe)Phe]: cyclo[(β-S)Pip-(NMe)Phe], cyclo[(γ-S)Pip-(NMe)Phe], cyclo[(δ-S)Pip-(NMe)Phe], cyclo[(β-S)Pro-(NMe)Phe] and cyclo[(γ-S)Pro-(NMe)Phe] were determined with X-ray crystallography. Density functional theory calculations of these molecules in the gas phase succeed in reproducing the observed molecular conforma

SUBMITTER: Budesinsky M 

PROVIDER: S-EPMC5744420 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature