Fmoc-Aph(Hor)-OH (CAS 1253282-31-3), also known as Fmoc-4-amino-L-phenylalanine (homoarginine) or Fmoc-L-Aph(Nω-homoarginyl)-OH, is a Fmoc-protected unnatural amino acid with a homoarginine (Hor) side chain modification on the para-aminophenyl group. It is an arylaminoalkyl guanidinyl Fmoc-amino acid. This special building block is used to make GnRH antagonists, especially Cetrorelix, Ganirelix, and other GnRH antagonist decapeptides. Modified Aph (aminophenyl alanine) residues with guanidinium-containing side chains are very important for high-affinity GnRH receptor binding and antagonist activity. Homoarginine, which is one carbon longer than Arg, has a unique guanidinium side chain length that changes how quickly receptors bind to it. To reduce racemization, HATU or HBTU coupling agents are better.
ApiSyn sells Fmoc-Aph(Hor)-OH (CAS 1253282-31-3) as a pharmaceutical-grade specialty building block for making GnRH antagonist peptides and doing related analytical work.
| Chemical Name | (S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(4-((S)-2,6-dioxohexahydropyrimidine-4-carboxamido)phenyl)propanoic acid |
| Molecular Formula | C29H26N4O7 |
| Molecular Weight | 542.5 |
| CAS Number | 1253282-31-3 |