title: Study of chemical ligation via 17-, 18- and 19-membered cyclic transition states.
abstract: Unprotected S-acylated cysteine isopeptides containing α-, β- or γ-amino acid units have been synthesized, and their conversion to native hexapeptides by S- to the N-terminus ligations involving 17-, 18- and 19-membered cyclic transition states have been demonstrated both experimentally and computationally to be more favorable than intermolecular cross-ligations.
authors.affiliation: Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA.
authors.forename: Siva S
authors.initials: SS
authors.lastname: Panda
authors.forename: Claudia
authors.initials: C
authors.lastname: El-Nachef
authors.forename: Kiran
authors.initials: K
authors.lastname: Bajaj
authors.forename: Abdulrahman O
authors.initials: AO
authors.lastname: Al-Youbi
authors.forename: Alexander
authors.initials: A
authors.lastname: Oliferenko
authors.forename: Alan R
authors.initials: AR
authors.lastname: Katritzky
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D008968:Molecular Conformation; D009584:Nitrogen / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*
chemical_list: D010455:Peptides; D013455:Sulfur; D003545:Cysteine; D009584:Nitrogen