AssayIndex

AX-2025-021130

Epitalon · 10 mg declared · Sigma-Aldrich (Shanghai) Trading Co., Ltd. · lot SIG-2412-6325

FAILMETHOD LIMITED
Report ID
AX-2025-021130
Compound
Epitalon
Compound class
Short bioregulator peptides
Supplier
SIG — Sigma-Aldrich (Shanghai) Trading Co., Ltd.
Batch / lot
SIG-2412-6325
Declared label claim
10mg
Laboratory
PeptideMeter
Assay date
03 Feb 2025
Submitted
05 Feb 2025
Quarter
2025-Q1
Submitter
ka.marchand
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the short bioregulator 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, 28 min gradient, 214 nm98.84% area≥ 99.0FAIL
Total impuritiesRP-HPLC, sum of reported peaks1.16% area≤ 1.0FAIL
Largest single impurityRP-HPLC — diketopiperazine (−18 Da)0.72% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula390.1387DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)390.1387DaNOT TESTED
Mass accuracyobserved vs theoretical-0.1ppm± 20PASS
Total peptide contentby difference from the gravimetric mass balance80.54%w/wNOT TESTED
Target-compound contenttotal peptide content × purity79.61%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen12.91mg10 mg declaredNOT TESTED
Recovered target peptidegross fill × target content10.278mg10 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim102.8%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate7.59%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography11.36%≤ 10.0FAIL
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.51%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 calibration5.232.5 – 8.0PASS
Retention time (observed)RP-HPLC, 28 min gradient4.38min4.34 ± 0.20 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.250.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²64,056≥ 20,000PASS
Resolution to nearest impurityvs β-Asp isomer1.32no 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.

05877117531763023507 Epitalon4.38 min · 98.84 % 4.53 same trace · ×100 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 051015202530 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 28 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 64,056, and skew follows the reported asymmetry factor of 1.25. 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 0.72 % impurity against a 98.84 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1Epitalon — main peak4.384,803,93098.84
2diketopiperazine (−18 Da)4.5334,9940.72-18.011
3aspartimide (−18 Da)4.4912,1510.25-18.011
4Ala-Glu-Asp tripeptide (−57 Da)4.194,8600.10-57.021
5β-Asp isomer4.294,3740.090.000
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 390.1387 Da, computed from C14H22N4O9. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100350375400425450475 [M+1H]1+391.15 m/z Relative abundance (%)
Figure 2. ESI charge-state envelope, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 390.1387 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 (%)
1+391.1460391.14600.0000100.0
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.

ComponentDetermination%w/w of cake
WaterKarl Fischer7.59
Counter-ion (acetate)ion chromatography11.36
Residual solvent + inorganic residueestimated0.51
Total peptide contentby difference80.54
Total100.00 CLOSES

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)99.4098.84divergence +0.30 pp vs batch median
Total impurities (% area)0.601.16
Largest single impurity (% area)0.370.72
Water (%)5.87.59
Counter-ion (%)not stated11.36
Peptide content (%w/w)not stated80.54
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, 28 d) → laboratory (hand-carried, 11 d) → assay.
Assay date
03 Feb 2025
Submitted to the index
05 Feb 2025
Laboratory
PeptideMeter, Tallinn, Estonia
Method basis
28 min gradient · high-resolution MS
Verification status
METHOD LIMITED
Section 6

Annotations 4

Signed technical comments from index contributors. Not a discussion forum — annotations question or contextualise the result, and the data team replies where a reply is warranted.

wide_iqr
The actionable statistic for a buyer is not the median but the tenth percentile — how bad a bad lot is. This record is a data point for that percentile and it is worth more to the index than another result at the top.
chain_custody
Custody from checkout to injection is documented on this record. Provenance plus custody is what makes a single result generalise past the vial it came from.
peak_integrator
Anyone comparing this purity figure against a result from a longer method should expect a difference of a few tenths in a predictable direction. The inter-lab page quantifies it per laboratory.
acetate_only
Acetate against trifluoroacetate changes the peptide mass fraction of the cake by several points at the same molar loading. Salt form is a real economic variable and it is almost never on the label.
Section 7

Related records

Same batch — lot SIG-2412-6325 n=12

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-021125SIG-2412-6325Janoshik2025-Q199.428.3089.6Buyer-sourced1MARGINAL
AX-2025-021126SIG-2412-6325Medutest2025-Q199.417.99Laboratory-retained0FAIL
AX-2025-021127SIG-2412-6325Janoshik2025-Q198.968.28Buyer-sourced0FAIL
AX-2025-021128SIG-2412-6325VendorInvestigate2025-Q198.678.21Buyer-sourced0FAIL
AX-2025-021129SIG-2412-6325Janoshik2025-Q199.237.18102.2Laboratory-retained0FAIL
AX-2025-021131SIG-2412-6325Nordanalyt2025-Q199.027.6690.7Buyer-sourced0FAIL
AX-2025-021132SIG-2412-6325VendorInvestigate2025-Q199.717.7688.6Buyer-sourced1FAIL
AX-2025-021133SIG-2412-6325PeptideMeter2025-Q199.528.24Buyer-sourced0PASS
AX-2025-021134SIG-2412-6325Janoshik2025-Q199.018.56Buyer-sourced0FAIL
AX-2025-021135SIG-2412-6325PeptideMeter2025-Q198.897.7391.5Buyer-sourced0FAIL
AX-2025-021136SIG-2412-6325Medutest2025-Q199.178.2594.3Buyer-sourced1FAIL
Other recent Epitalon records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042008AMBAMB-2602-Y6433Janoshik2026-Q399.308.75105.1Buyer-sourced0PASS
AX-2026-042009AMBAMB-2602-Y6433VendorInvestigate2026-Q399.168.62102.3Buyer-sourced0FAIL
AX-2026-042010AMBAMB-2602-Y6433Janoshik2026-Q399.098.20103.4Laboratory-retained0FAIL
AX-2026-042007AMBAMB-2602-Y6433Janoshik2026-Q399.428.6293.8Buyer-sourced0FAIL
AX-2026-042468HomopeptideHOMO-2512-A5108Janoshik2026-Q299.937.81100.8Buyer-sourced0PASS
AX-2026-042463HomopeptideHOMO-2512-A5108Janoshik2026-Q299.937.6893.2Buyer-sourced0FAIL
AX-2026-042041HYBHYB-2603-U7133Janoshik2026-Q299.656.8295.3Buyer-sourced0FAIL
AX-2026-042470HomopeptideHOMO-2512-A5108Janoshik2026-Q299.637.99Buyer-sourced0FAIL
Other recent SIG records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043535GHRP-2SIG-2603-6031Janoshik2026-Q399.121.26105.7Buyer-sourced0PASS
AX-2026-043541GHRP-2SIG-2603-6031PeptideMeter2026-Q399.062.08107.4Buyer-sourced1MARGINAL
AX-2026-043539GHRP-2SIG-2603-6031Janoshik2026-Q398.951.74100.4Buyer-sourced1FAIL
AX-2026-043534GHRP-2SIG-2603-6031Medutest2026-Q399.112.1589.8Buyer-sourced1MARGINAL
AX-2026-043542GHRP-2SIG-2603-6031VendorInvestigate2026-Q399.051.43Buyer-sourced1FAIL
AX-2026-043543GHRP-2SIG-2603-6031Janoshik2026-Q399.381.7098.6Buyer-sourced0PASS
AX-2026-043544GHRP-2SIG-2603-6031PeptideMeter2026-Q399.571.51105.4Buyer-sourced0PASS
AX-2026-043538GHRP-2SIG-2603-6031Kestrel2026-Q398.931.72Buyer-sourced0FAIL