AssayIndex
Neuroactive and cognitive peptides

P21

P021 · Ac-DGGLAG-NH2 adamantyl · C36H55N9O12 · monoisotopic 805.3970 Da. The index holds 4 assay reports on this compound across 1 batches from 1 suppliers.

4 reports1 batchesmedian 99.19 %index spec 98.0 %
Section 1

Analytical fingerprint

Hand-authored chemistry. These properties describe the substance and do not change when a record is added.

P21 is an adamantylated hexapeptide amide derived from a CNTF fragment. The adamantyl group is worth 2 min of retention, so the des-adamantyl impurity is far from the main peak and easy to quantify — one of the few compounds here where the diagnostic impurity is trivially resolved. Thin coverage.

Molecular formula
C36H55N9O12
Monoisotopic mass
805.3970Da
Average mass
805.88Da
Residues
6
Nominal retention (RG-2, 30 min)
10.42min
Retention window
0.30min
Counter-ion as usually shipped
acetate
Typical label claims
5 mg · 10 mg
Analytical difficulty (index scale)
0.85 — straightforward
Purity is a defined quantity
YES
Section 2

Representative chromatogram

Drawn from this page's own medians. Not a scan, not an illustration, and not any single report.

025715141771210283 P2110.42 min · 99.19 % 10.728.36 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. A representative P21 trace on the index reference method RG-2, constructed from this page's own numbers: the main peak carries the index median purity of 99.19 % area at the nominal retention time of 10.42 min, and each impurity peak carries the median area the index has observed for that named species at its characteristic retention offset. It is not a scan of any single report — every individual record's own chromatogram is on its own page. The lower panel is the same trace at a stated vertical expansion, baseline-corrected, so the impurities are visible; the main peak runs off-scale there by design. Baseline noise is seeded from the compound slug.
Section 3

What the index has observed

Arithmetic over the 4 records the index holds. Aggregates on this page are computed over the records the index holds, which are not a random sample of the material on the market. Lots that get tested are lots someone chose to test. Read every figure here as a description of this dataset rather than as an estimate of a population.

Median purity 99.19% n=4
Interquartile range 0.34pp n=4
Minimum 98.88% n=4
Maximum 99.83% n=4
Pass rate vs spec 100.0% n=4
Median recovery vs claim suppressed n=2 n<3 — see individual records
Median water 8.39% n=4
Median |mass error| 2.5ppm n=4

Fewer than twelve purity records (n=4) — a histogram of this would be a picture of the sample size rather than of the compound. The individual values are in the table below.

Section 5

Characteristic impurities and degradants

The left three columns are authored chemistry — what this molecule characteristically carries and where it elutes. The right three are what the index has actually reported.

Named speciesΔRT (min, RG-2)Δ mass (Da)Seen inMedian % areaMax % area
des-adamantyl (−134 Da)-2.06-134.110100%0.170.33
free acid (+1 Da)+0.22+0.984100%0.100.44
aspartimide (−18 Da)+0.30-18.011100%0.320.62
des-acetyl (−42 Da)-0.42-42.01175%0.070.10

Degradation pathways

  • adamantylation loss
  • aspartimide at the Asp-Gly motif

Full impurity profile, with what each named species implies about the synthesis →

Section 7

Quarterly coverage

QuarterReportsMedian purityRange
2024-Q10n<3
2024-Q20n<3
2024-Q30n<3
2024-Q40n<3
2025-Q1499.1998.88–99.83
2025-Q20n<3
2025-Q30n<3
2025-Q40n<3
2026-Q10n<3
2026-Q20n<3
2026-Q30n<3

Quarter-by-quarter detail →

Section 8

Most recent records

The 25 most recent P21 records of 4.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-019900SWBSWB-2408-T5745Medutest2025-Q199.838.60100.9Supplier-supplied0PASS
AX-2025-019902SWBSWB-2408-T5745Nordanalyt2025-Q199.138.3099.0Supplier-supplied1MARGINAL
AX-2025-019903SWBSWB-2408-T5745Medutest2025-Q198.888.08Buyer-sourced0PASS
AX-2025-019901SWBSWB-2408-T5745Nordanalyt2025-Q199.268.49Supplier-supplied0PASS