title: Detection and control of aspartimide formation in the synthesis of cyclic peptides.
abstract: Extensive two-dimensional NMR analysis was employed to characterize the structural identity of the macrocyclic peptide lactam and the imide analog, a major side reaction product when allyl ester was used to protect the side chain of aspartic acid. A straightforward protocol modification was developed to minimize aspartimide formation during the synthesis of cyclic peptides.
authors.affiliation: Lilly Research Laboratories, A Division of Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN 46285, USA.
authors.forename: David
authors.initials: D
authors.lastname: Flora
authors.forename: Huaping
authors.initials: H
authors.lastname: Mo
authors.forename: John P
authors.initials: JP
authors.lastname: Mayer
authors.forename: M Amin
authors.initials: MA
authors.lastname: Khan
authors.forename: Liang Z
authors.initials: LZ
authors.lastname: Yan
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives*; D020650:Combinatorial Chemistry Techniques; D007769:Lactams; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000302:isolation & purification; D011786:Quality Control
chemical_list: D007769:Lactams; D010456:Peptides, Cyclic; D001224:Aspartic Acid; C075871:aspartimide