AssayIndex

AX-2024-005341

Epitalon · 50 mg declared · Sigma-Aldrich (Shanghai) Trading Co., Ltd. · lot SIG-2308-5947

FAILMETHOD LIMITED
Report ID
AX-2024-005341
Compound
Epitalon
Compound class
Short bioregulator peptides
Supplier
SIG — Sigma-Aldrich (Shanghai) Trading Co., Ltd.
Batch / lot
SIG-2308-5947
Declared label claim
50mg
Laboratory
Janoshik Analytical
Assay date
10 Mar 2024
Submitted
19 Mar 2024
Quarter
2024-Q1
Submitter
k.lundgren
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, 30 min gradient, 214 nm98.97% area≥ 99.0FAIL
Total impuritiesRP-HPLC, sum of reported peaks1.03% area≤ 1.0FAIL
Largest single impurityRP-HPLC — β-Asp isomer0.48% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula390.1387DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)390.1391DaNOT TESTED
Mass accuracyobserved vs theoretical+0.9ppm± 20PASS
Total peptide contentby difference from the gravimetric mass balance80.31%w/wNOT TESTED
Target-compound contenttotal peptide content × purity79.48%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen55.88mg50 mg declaredNOT TESTED
Recovered target peptidegross fill × target content44.413mg50 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim88.8%90.0 – 110.0FAIL
Water contentKarl Fischer, coulometric, duplicate9.38%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography9.46%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.85%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 backgroundWhite cake, partially collapsedwhite to off-white intact cakeFAIL
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulatesclear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration5.632.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient4.60min4.62 ± 0.20 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.110.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²45,547≥ 20,000PASS
Resolution to nearest impurityvs β-Asp isomer1.13no 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.

05038100761511420152 Epitalon4.60 min · 98.97 % 4.50 same trace · ×100 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 30 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 45,547, and skew follows the reported asymmetry factor of 1.11. 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 0.48 % impurity against a 98.97 % 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 peak4.604,810,24998.97
2β-Asp isomer4.5023,3290.480.000
3aspartimide (−18 Da)4.7213,1230.27-18.011
4Ala-Glu-Asp tripeptide (−57 Da)4.407,7760.16-57.021
5diketopiperazine (−18 Da)4.765,8320.12-18.011
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 390.1391 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+391.1460391.14640.0004100.0
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 Fischer9.38
Counter-ion (acetate)ion chromatography9.46
Residual solvent + inorganic residueestimated0.85
Total peptide contentby difference80.31
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)98.8698.97divergence -0.05 pp vs batch median
Total impurities (% area)1.141.03
Largest single impurity (% area)0.840.48
Water (%)8.29.38
Counter-ion (%)9.39.46
Peptide content (%w/w)81.980.31
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 (2–8 °C, 11 d) → laboratory (courier, ambient, 5 d) → assay.
Assay date
10 Mar 2024
Submitted to the index
19 Mar 2024
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 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.

scale_up_delta
Purity commonly falls a few tenths between pilot and production scale, and a result below a laboratory-batch figure is the most ordinary thing in this dataset. Comparing a commercial lot against a research-batch certificate compares two different processes.
dimer_disulfide
An intermolecular disulfide dimer elutes late and reduces cleanly. If the named table shows one, a non-reducing versus reducing comparison converts an unexplained impurity into an explained one.
ppm_error
Well inside class limit. Worth noting that the class limits are set by mass rather than globally, because the same ppm is a different number of daltons at 340 and at 4,800.
gradient_25
Resolution scales with the square root of plate count and linearly with selectivity. Shallowing the gradient changes selectivity, which is the more effective of the two levers on a close pair.
Section 7

Related records

Same batch — lot SIG-2308-5947 n=4

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2024-005338SIG-2308-5947Janoshik2024-Q199.209.2198.7Buyer-sourced0PASS
AX-2024-005339SIG-2308-5947PeptideMeter2024-Q198.859.25Buyer-sourced0FAIL
AX-2024-005340SIG-2308-5947Janoshik2024-Q198.659.0689.6Buyer-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