13 research outputs found
Conjugation of Methotrexate-Amino Derivatives to Macromolecules through Carboxylate Moieties Is Superior Over Conventional Linkage to Amino Residues: Chemical, Cell-Free and In Vitro Characterizations
Prolonged antidiabetic effect of zinc-crystallized insulin loaded glycol chitosan nanoparticles in type 1 diabetic rats
Insulin-Mimetic Vanadyl(IV) Complexes as Evaluated by Both Glucose-Uptake and Inhibition of Free Fatty Acids (FFA)-Release in Isolated Rat Adipocytes
Stable right- and left-handed peptide helices containing Cα-tetrasubstituted α amino acids
Short peptidomimetics with stable secondary structures in solution are of interest for applications in chemistry, biology, and medicine. One way to rigidify the backbone of a peptide is the use of cyclic Cα-tetrasubstituted α-amino acids (TAAs) like compound 14. The structures resulting from the incorporation of this unnatural amino acid into peptides were investigated. In total, 13 different peptides with a length of up to eight residues and alternating sequences of TAA 14 and (S)- or (R)-valine were synthesized. Their structures were characterized by X-ray diffraction analysis and NMR and CD measurements showing that the all-S-backbone-configured peptides 5 and 6 (SS)2−3 form right-handed 310-helices, while the all-R-configured peptides 11−13 (RR)2−4 form left-handed 310-helices in the solid state and solution