[D-Arg1,D-Pro2,D-Trp7,9,Leu11]-Substance P is a full-length modified Substance P analog containing D-Arg1, D-Pro2, D-Trp7, D-Trp9 and Leu11 substitutions.

The peptide belongs to the early high-potency generation of Substance P antagonists and has been used to investigate tachykinin-dependent neural, vascular and smooth-muscle responses.

Product Information

A High-Potency Early Substance P Antagonist

Comparative biological evaluation placed this peptide among the strongest undecapeptide antagonists of its generation. Reported pA₂ values were approximately 7.1–7.2 in classical tissue preparations.

D-Pro2 distinguishes this analog from Spantide I, while the two peptides otherwise share D-Arg1, D-Trp7,9 and Leu11 substitutions.

Free Peptide Versus Acetate Salt CAS

The free peptide is associated with CAS 84676-91-5. CAS 143077-65-0 is used for the acetate salt and should not be substituted unless the supplied material is specifically identified as that salt form.

We recommend keeping salt form explicit in purchasing records and certificates because counterions can affect reported formula weight and peptide content calculations.

Research Applications

The peptide can support Substance P antagonist research, tachykinin functional assays, vascular and neural studies and comparative analysis of early peptide antagonist scaffolds.

Frequently Asked Questions

Is this peptide the same as Spantide I?

No. It contains an additional D-Pro substitution at position 2.

What CAS should be used for the free peptide?

CAS 84676-91-5. CAS 143077-65-0 refers to an acetate salt form.

Does it contain Met11?

No. Met11 is replaced by Leu.

Research Use Only.