Fmoc-Val-OH (CAS 68858-20-8), also known as Nα-Fmoc-L-valine, is the standard Fmoc-protected valine for Fmoc-SPPS. It belongs to the Fmoc-branched aliphatic amino acid class. The isopropyl side chain of valine doesn't need any extra protection, which makes synthesis easier. It is an amino acid that doesn't like water and helps peptides pack their hydrophobic cores. Val is found in GLP-1 analogues, GnRH, oxytocin (Val3), and many therapeutic peptides (Lanreotide Val5).
Fmoc-Val-OH coupling can be sterically demanding in long beta-sheet-prone sequences because it is a β-branched amino acid (like Ile and Thr). This means that double coupling or microwave help is needed. Under SPPS conditions, valine is more resistant to racemization than other amino acids that don't have branches.
ApiSyn sells Fmoc-Val-OH (CAS 68858-20-8) as a pharmaceutical-grade Fmoc amino acid and a critical raw material reference standard for making and testing GMP pharmaceutical peptides.
| Chemical Name | (((9H-Fluoren-9-yl)methoxy)carbonyl)-L-valine |
| Molecular Formula | C20H21NO4 |
| Molecular Weight | 339.4 |
| CAS Number | 68858-20-8 |