What is KPV's PubChem CID?

125672, indexed as Lys-Pro-Val at 342.43 Da. Searching KPV returns CID 13294447, an unrelated organic acid.

Why does the abbreviation return the wrong compound?

Three-character strings collide in large chemical databases. Searching the sequence avoids it.

How do I verify a batch?

Mass spectrometry against 342.43 Da. No cysteine or methionine means no disulfide or oxidation satellites should appear.

KPV

KPV Chemical Identity

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-232 cited sources

The KPV peptide is indexed in PubChem as Lys-Pro-Val at CID 125672, molecular weight 342.43 Da, formula C16H30N4O4. Searching the three-letter abbreviation instead returns 2-oxo-5-phenylpentanoic acid — a completely unrelated compound.

Key facts

Correct record: CID 125672, Lys-Pro-Val
Molecular weight: 342.43 Da
Formula: C16H30N4O4
Searching 'KPV' returns: CID 13294447, an organic acid
That compound: 2-oxo-5-phenylpentanoic acid, 192.21 Da
Practical rule: Search the sequence, not the abbreviation

What goes wrong

PubChem matches KPV to 2-oxo-5-phenylpentanoic acid, C11H12O3 at 192.21 Da. It is not a peptide, has no relationship to alpha-MSH, and shares nothing with the tripeptide beyond three letters. Anyone verifying a certificate by searching KPV finds this record, and nothing about it announces that it is the wrong compound.

How to find the right one

Search Lys-Pro-Val, which returns CID 125672 at 342.43 Da for C16H30N4O4. The 150 Da difference between the two records is unmistakable once both are in front of you — the difficulty is only that a search for the common name never surfaces the peptide at all.

Research material referenced

KPV 10mg — third-party HPLC tested

View — £24.99

Why three-letter names collide

Short abbreviations have limited space and databases index enormous numbers of compounds. A three-character string will inevitably match something unintended somewhere. This is a general hazard rather than a KPV-specific one, and it is an argument for using sequences as identifiers wherever a peptide is concerned.

The pattern across this library

This is the fourth identifier collision found here. A PubChem record for tirzepatide was cited as retatrutide. CAS 77591-33-4 for thymosin beta-4 was quoted as TB-500's. CID 71145 was cited as GHK-Cu. Now KPV resolves to an organic acid. Every one looked plausible and every one was wrong, which is the argument for checking rather than assuming.

Confirming a batch

Mass spectrometry against 342.43 Da. There is no cysteine and no methionine, so neither disulfide species nor a +16 Da satellite should appear. At three residues the synthesis is trivial and purity should be high, though the compound's poor retention on reverse-phase columns can complicate the chromatography.

Extended research context

The KPV deep dive

Deep dive: two functions in one hormone, and the case for splitting them

Alpha-MSH is a thirteen-residue peptide cleaved from proopiomelanocortin, and it does two things that have almost nothing to do with each other. Its core sequence engages melanocortin receptors on melanocytes and drives melanin synthesis - the activity it is named for. Separately, it carries anti-inflammatory activity that Brzoska and colleagues localised to its C-terminal end, a paper titled 'terminal signal' precisely because the finding was that the signal sits at the terminus rather than in the receptor-binding core. That is an unusually clean functional separation, and it produced two research compounds pulling in opposite directions from one parent. KPV takes the C-terminal three residues and discards the pigmentation activity. Melanotan II does the reverse - a cyclic analogue built around the receptor-binding portion to maximise exactly what KPV was designed to leave behind. Same hormone, opposite halves.

Deep dive: what happens when you shrink a molecule fivefold

Going from alpha-MSH at 1,664.9 Da to KPV at 342.43 Da is not a trim, it is a change of category. A 1,665 Da peptide is firmly a cell-surface ligand - far too large to cross a membrane passively, so whatever it does must begin at a receptor. A 342 Da tripeptide is small enough that intracellular access becomes plausible, which is why KPV's reported mechanism is described in terms of NF-kappaB signalling rather than melanocortin receptor engagement. The consequence is rarely stated: if the fragment acts inside the cell and the parent acts at its surface, then the anti-inflammatory activity of the two is not necessarily the same phenomenon, and read-across between them should run cautiously in both directions. Fragment logic assumes the fragment is the parent minus something. Here it may be the parent minus something plus a different route of access.

Deep dive: the delivery paper is the most informative thing in the literature

Xiao and colleagues published in Molecular Therapy in 2017 on delivering KPV orally using hyaluronic acid-functionalised nanoparticles targeted to inflamed intestinal tissue. Read as a result it is a delivery success. Read as a statement about the compound it is more interesting: nobody builds a targeted nanoparticle carrier for a molecule that already reaches its target. The existence of that work says the free tripeptide's arrival at inflamed tissue was the limiting problem - which follows directly from being 342 Da, highly soluble and rapidly cleared. It is the same signal that CJC-1295's DAC modification carries for growth hormone secretagogues, or that lipidation carries across the whole incretin class: when the engineering effort goes into getting a compound to stay and arrive rather than into making it more active, the pharmacokinetics were the bottleneck.

Research applications

▸Melanocortin fragment structure-activity research
▸NF-kappaB pathway and cytokine production studies in culture
▸Murine models of induced intestinal inflammation
▸Targeted peptide delivery and carrier system development
▸Comparative work on parent hormones and isolated fragments
▸Analytical method development for very short peptides

Handling checklist

✓Verify identity against Lys-Pro-Val, CID 125672, at 342.43 Da
✓Do not search PubChem for 'KPV' - it returns an unrelated organic acid
✓Store lyophilised, cold, dry and dark
✓Use low-binding consumables; a small cationic peptide adsorbs to surfaces
✓Reconstitute gently down the vial wall and swirl, never shake
✓Aliquot into single-use volumes to avoid freeze-thaw cycling
✓Expect no disulfide or oxidation satellites - no cysteine, no methionine

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Searching PubChem for 'KPV' to verify a certificate

Fix: That returns CID 13294447, 2-oxo-5-phenylpentanoic acid at 192.21 Da, an unrelated compound. Search Lys-Pro-Val for CID 125672.

✗ Treating KPV and alpha-MSH findings as interchangeable

Fix: They differ fivefold in mass and the fragment may act intracellularly where the parent cannot. Read across cautiously in both directions.

✗ Assuming a colitis model result speaks to inflammatory bowel disease

Fix: Induced colitis in a mouse is acute and chemical; human IBD is chronic, heterogeneous and immunologically complex.

✗ Expecting to quantify KPV by absorbance at 280 nm

Fix: There is no aromatic residue in the sequence, so there is no usable absorbance there.

✗ Attributing unexplained low recovery to degradation

Fix: KPV is chemically robust - no cysteine, methionine or asparagine. Adsorption to glass and plastic is the more likely cause.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Frequently asked questions

What is KPV's PubChem CID?: 125672, indexed as Lys-Pro-Val at 342.43 Da. Searching KPV returns CID 13294447, an unrelated organic acid.
Why does the abbreviation return the wrong compound?: Three-character strings collide in large chemical databases. Searching the sequence avoids it.
How do I verify a batch?: Mass spectrometry against 342.43 Da. No cysteine or methionine means no disulfide or oxidation satellites should appear.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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