AssayIndex

AX-2026-042797

Selank · 5 mg declared · Nantong Guangyuan Chemical Co., Ltd. · lot GGPE-2602-G2056

FAILIDENTITY CONSISTENT
Report ID
AX-2026-042797
Compound
Selank
Compound class
Neuroactive and cognitive peptides
Supplier
GGPeps — Nantong Guangyuan Chemical Co., Ltd.
Batch / lot
GGPE-2602-G2056
Declared label claim
5mg
Laboratory
Medutest
Assay date
09 Sep 2026
Submitted
01 Oct 2026
Quarter
2026-Q3
Submitter
a.correia
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the neuroactive and cognitive peptides class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 25 min gradient, 214 nm98.46% area≥ 99.0FAIL
Total impuritiesRP-HPLC, sum of reported peaks1.54% area≤ 1.0FAIL
Largest single impurityRP-HPLC — tuftsin fragment (−417 Da)0.73% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula751.4402DaNOT TESTED
Identity — observed monoisotopic massLC-MS, unit resolution (single quadrupole)751.4407DaNOT TESTED
Mass accuracyobserved vs theoretical+0.7ppm± 15PASS
Peptide contentnot ordered on this submissionnot determinedrequired to check label claimNOT TESTED
Water contentKarl Fischer, coulometric, duplicate7.92%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography6.88%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.88%NOT TESTED
Endotoxinnot ordered on this submissionnot determined≤ 5.0NOT TESTED
Sterilitynot ordered on this submissionnot determinedno growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundOff-white lyophilised cake, intactwhite to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulatesclear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration4.532.5 – 8.0PASS
Retention time (observed)RP-HPLC, 25 min gradient5.47min5.44 ± 0.25 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.460.990.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²78,926≥ 20,000PASS
Resolution to nearest impurityvs diketopiperazine (−18 Da)1.88no index criterionREPORTED
Section 2

Chromatogram and peak integration

The figure is drawn from the table. It is not an independent illustration — if a number in the table changed, the trace would change with it.

05883117661764923532 Selank5.47 min · 98.46 % 4.95 same trace · ×50 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 0481216202428 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 25 min gradient, 214 nm. Drawn from the peak-integration table below: peak positions are the reported retention times, peak areas are the reported area percentages, peak widths follow the reported plate count of 78,926, and skew follows the reported asymmetry factor of 0.99. Baseline noise is seeded from the report ID and is illustrative. The lower panel is the same trace at a stated vertical expansion with the slow gradient drift subtracted, because at full scale a 0.73 % impurity against a 98.46 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1Selank — main peak5.474,785,46198.46
2tuftsin fragment (−417 Da)4.9535,4800.73-417.235
3diketopiperazine (−18 Da)5.6221,8710.45-18.011
4acetyl adduct (+42 Da)5.7511,6650.24+42.011
5des-Thr (−101 Da)5.255,8320.12-101.048
Closure check — purity + Σ impurities 100.00CLOSES

Reporting threshold 0.05 % area. Peaks below it are not reported and are therefore excluded from the total, which overstates purity by their sum — see peak integration.

Section 3

Mass spectrum and identity

Theoretical monoisotopic mass 751.4402 Da, computed from C33H57N11O9. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100325425525625725825 [M+1H]1+752.45[M+2H]2+376.73 m/z Relative abundance (%)
Figure 2. ESI charge-state envelope, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 751.4407 Da. Sodium (+21.982/z) and potassium (+37.956/z) adducts are shown where the parent charge state exceeds 25 % relative abundance; they are adducts of the same molecule and are not impurities.
ChargeTheoretical m/zObserved m/zΔ m/zRel. abundance (%)
2+376.7274376.72760.000255.6
1+752.4475752.44800.0005100.0
Section 4

Gravimetric mass balance

Water, counter-ion, residual and total peptide content are exhaustive and mutually exclusive categories. They must account for 100 % of the cake mass. The index closes this to within 0.02 pp and the build asserts it.

Supplier certificate, as declared

The supplier's own figures for this lot, beside the independent measurement. Divergence is assessed against the batch median, not against this single report — see rule AX-R05.

FigureSupplier COAThis reportIndex note
Purity (% area)99.2698.46divergence +0.76 pp vs batch median
Total impurities (% area)0.741.54
Largest single impurity (% area)not stated0.73
Water (%)6.97.92
Counter-ion (%)not stated6.88
Peptide content (%w/w)88.3not determined
Endotoxin (EU/mg)not statednot determined
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Provenance and caveats

Where a sample came from changes the weight of the evidence. The index treats it as a first-class field.

Sample provenance
Buyer-sourced
Evidentiary weight
Strongest available evidence in this index.
Chain of custody
Retail purchase → submitter (ambient, 1 d) → laboratory (courier, cold pack, 7 d) → assay.
Assay date
09 Sep 2026
Submitted to the index
01 Oct 2026
Laboratory
Medutest, Ljubljana, Slovenia
Method basis
25 min gradient · unit-resolution MS
Verification status
IDENTITY CONSISTENT
Section 6

Annotations

No annotations on this record. Annotations are short signed technical comments from index contributors; see how to contribute.

Section 7

Related records

Same batch — lot GGPE-2602-G2056 n=9

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042796GGPE-2602-G2056Janoshik2026-Q398.267.5697.5Buyer-sourced0FAIL
AX-2026-042798GGPE-2602-G2056Janoshik2026-Q398.398.0499.6Laboratory-retained0FAIL
AX-2026-042799GGPE-2602-G2056Nordanalyt2026-Q398.778.33Supplier-supplied0FAIL
AX-2026-042800GGPE-2602-G2056Janoshik2026-Q398.608.0690.6Supplier-supplied0FAIL
AX-2026-042801GGPE-2602-G2056Medutest2026-Q399.677.2694.7Supplier-supplied0PASS
AX-2026-042802GGPE-2602-G2056Janoshik2026-Q398.747.0996.0Supplier-supplied0FAIL
AX-2026-042803GGPE-2602-G2056Janoshik2026-Q398.488.01Laboratory-retained1FAIL
AX-2026-042804GGPE-2602-G2056Janoshik2026-Q398.507.97Supplier-supplied0FAIL
Other recent Selank records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042737GGPepsGGPE-2603-J9708Janoshik2026-Q398.409.1497.4Buyer-sourced0FAIL
AX-2026-042804GGPepsGGPE-2602-G2056Janoshik2026-Q398.507.97Supplier-supplied0FAIL
AX-2026-042803GGPepsGGPE-2602-G2056Janoshik2026-Q398.488.01Laboratory-retained1FAIL
AX-2026-042802GGPepsGGPE-2602-G2056Janoshik2026-Q398.747.0996.0Supplier-supplied0FAIL
AX-2026-042796GGPepsGGPE-2602-G2056Janoshik2026-Q398.267.5697.5Buyer-sourced0FAIL
AX-2026-042743GGPepsGGPE-2603-J9708Medutest2026-Q399.599.37Supplier-supplied0PASS
AX-2026-042799GGPepsGGPE-2602-G2056Nordanalyt2026-Q398.778.33Supplier-supplied0FAIL
AX-2026-042739GGPepsGGPE-2603-J9708PeptideMeter2026-Q399.039.09102.1Supplier-supplied0PASS
Other recent GGPeps records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042737SelankGGPE-2603-J9708Janoshik2026-Q398.409.1497.4Buyer-sourced0FAIL
AX-2026-042804SelankGGPE-2602-G2056Janoshik2026-Q398.507.97Supplier-supplied0FAIL
AX-2026-042803SelankGGPE-2602-G2056Janoshik2026-Q398.488.01Laboratory-retained1FAIL
AX-2026-042802SelankGGPE-2602-G2056Janoshik2026-Q398.747.0996.0Supplier-supplied0FAIL
AX-2026-042796SelankGGPE-2602-G2056Janoshik2026-Q398.267.5697.5Buyer-sourced0FAIL
AX-2026-042648Melanotan IIGGPE-2603-P8735Janoshik2026-Q399.106.97Supplier-supplied4MARGINAL
AX-2026-042669CJC-1295 (no DAC)GGPE-2606-E8495Medutest2026-Q398.614.0695.5Supplier-supplied0PASS
AX-2026-042743SelankGGPE-2603-J9708Medutest2026-Q399.599.37Supplier-supplied0PASS