Mechanism study on the Oligomerization of Amino Acids into Peptides by Phosphorus Trichloride
作者:Wenjie Zhao、Dongxin Zhao、Kui Lu
DOI:10.1080/10426500701807467
日期:2008.1.14
As treated by phosphorustrichloride, amino acids could oligomerize into polypeptides. Based on the results obtained by 31P-NMR and ESI-MS/MS, a possible reaction mechanism was proposed. The mechanism might undergo a penta-coordinated phosphorus intermediat. The activated amino acid was a five-membered cyclic penta-coordinated phosphorus intermediate. The nucleophilic attack of the amino group from
Cyclic Penta- and Hexaleucine Peptides without <i>N</i>-Methylation Are Orally Absorbed
作者:Timothy A. Hill、Rink-Jan Lohman、Huy N. Hoang、Daniel S. Nielsen、Conor C. G. Scully、W. Mei Kok、Ligong Liu、Andrew J. Lucke、Martin J. Stoermer、Christina I. Schroeder、Stephanie Chaousis、Barbara Colless、Paul V. Bernhardt、David J. Edmonds、David A. Griffith、Charles J. Rotter、Roger B. Ruggeri、David A. Price、Spiros Liras、David J. Craik、David P. Fairlie
DOI:10.1021/ml5002823
日期:2014.10.9
peptide-based drugs has been severely limited by lack of oral bioavailability with less than a handful of peptides being truly orally bioavailable, mainly cyclic peptides with N-methyl amino acids and few hydrogen bond donors. Here we report that cyclic penta- and hexa-leucine peptides, with no N-methylation and five or six amide NH protons, exhibit some degree of oral bioavailability (4–17%) approaching that