[Sar9] Substance P is a full-length Substance P analog in which Gly9 is replaced by sarcosine, also known as N-methylglycine.

The modification introduces an N-methyl group into the peptide backbone near the C-terminal receptor-recognition region. [Sar9] Substance P is used as a potent and selective NK1 receptor agonist in tachykinin pharmacology.

Product Information

Sar9 Introduces Backbone N-Methylation

Sarcosine is N-methylglycine. Replacing Gly9 with Sar therefore retains a compact residue at this position while adding a methyl group directly to the peptide backbone nitrogen.

Backbone N-methylation can alter local conformation, hydrogen-bonding behavior and protease recognition. This makes Sar9 useful for probing the structural requirements of the C-terminal Substance P pharmacophore.

NK1 Receptor Agonist Activity

[Sar9] Substance P is used as an NK1 receptor agonist in receptor and neuronal signaling studies. Its value is distinct from the widely used [Sar9,Met(O2)11]-Substance P analog because [Sar9] Substance P retains native Met11.

We recommend keeping these two reagents clearly separated in experimental records. Oxidized Met11 introduces additional chemistry that is not present in the unoxidized [Sar9] product.

Research Applications

[Sar9] Substance P can support NK1 receptor activation studies, Substance P structure–activity research, neuronal signaling experiments and comparisons of backbone-methylated tachykinin analogs.

Because native Met11 remains present, oxidation should be monitored during extended storage or stability-sensitive experiments.

Frequently Asked Questions

What is Sar?

Sarcosine is N-methylglycine.

Which residue is replaced?

Gly9 of native Substance P is replaced with Sar.

Is [Sar9] Substance P an NK1 agonist?

Yes. It is used as a potent selective NK1 receptor agonist.

Is this the same as [Sar9,Met(O2)11]-Substance P?

No. [Sar9] Substance P retains native methionine at position 11 and does not contain the Met(O2) modification.

Research Use Only.