Side-reactions in peptide synthesis. 2. Formation of by-products in the large-scale synthesis of THF-gamma 2 by solution synthesis.
The impurities which formed in the large-scale synthesis of THF-gamma 2, an immunomodulatory peptide of formula H-Leu-Glu-Asp-Gly-Pro-Lys-Phe-Leu-OH, were identified by a combination of analytical methods, and their structure confirmed by synthesis. Most impurities originated from side-reactions involving the aspartyl residue (cyclization, beta-aspartyl formation and cleavage). Based on this knowledge, modifications were introduced into the work up and the purification procedure which resulted in a very pure final product (> 99% by RP-HPLC).
Forino
R
R
Farmitalia Carlo Erba S.r.l., Research and Development, Nerviana (MI), Italy.
Galantino
M
M
Ciprandi
F
F
Baumer
L
L
Arlandini
E
E
De Castiglione
R
R
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000302:isolation & purification; D013951:Thymus Hormones / Q000138:chemical synthesis / Q000302:isolation & purification
D009842:Oligopeptides; D013951:Thymus Hormones; C064563:thymic humoral factor gamma 2