AX-2024-005561 · Selank · BCH lot BCH-2407-M7005

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.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 28 min gradient, 214 nm	98.98	% area	≥ 99.0	FAIL
Total impurities	RP-HPLC, sum of reported peaks	1.02	% area	≤ 1.0	FAIL
Largest single impurity	RP-HPLC — diketopiperazine (−18 Da)	0.50	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	751.4402	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	751.4409	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+0.9	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	86.80	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	85.91	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	24.24	mg	20 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	20.825	mg	20 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	104.1	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	6.69	%	≤ 12.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	5.53	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.98	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	1.11	EU/mg	≤ 5.0	PASS
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	White lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	4.87	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	6.00	min	6.03 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.01	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	61,545	—	≥ 20,000	PASS
Resolution to nearest impurity	vs diketopiperazine (−18 Da)	1.69	—	no index criterion	REPORTED

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.

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 61,545, and skew follows the reported asymmetry factor of 1.01. 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 0.50 % impurity against a 98.98 % main peak is a line two pixels tall; the main peak runs off-scale there by design.

#	Peak	RT	Area (µV·s)	% area	Δ mass (Da)
1	Selank — main peak	6.00	4,810,735	98.98	—
2	diketopiperazine (−18 Da)	6.17	24,302	0.50	-18.011
3	des-Thr (−101 Da)	5.76	13,609	0.28	-101.048
4	acetyl adduct (+42 Da)	6.32	7,290	0.15	+42.011
5	tuftsin fragment (−417 Da)	5.42	4,374	0.09	-417.235
Closure check — purity + Σ impurities				100.00	CLOSES

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.

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 751.4409 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.

Charge	Theoretical m/z	Observed m/z	Δ m/z	Rel. abundance (%)
2+	376.7274	376.7277	0.0003	52.5
1+	752.4475	752.4482	0.0007	100.0

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.

Component	Determination	%w/w of cake
Water	Karl Fischer	6.69
Counter-ion (acetate)	ion chromatography	5.53
Residual solvent + inorganic residue	estimated	0.98
Total peptide content	by difference	86.80
Total		100.00 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.

Figure	Supplier COA	This report	Index note
Purity (% area)	99.5	98.98	divergence +0.24 pp vs batch median
Total impurities (% area)	0.50	1.02
Largest single impurity (% area)	not stated	0.50
Water (%)	6.5	6.69
Counter-ion (%)	not stated	5.53
Peptide content (%w/w)	not stated	86.80
Endotoxin (EU/mg)	not stated	1.11
Method stated on certificate	NO	—	no method section — the result cannot be reconciled against any other

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, 30 d) → laboratory (courier, cold pack, 7 d) → assay.
Assay date: 17 Aug 2024
Submitted to the index: 28 Aug 2024
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

That the material is sterile. Sterility was not tested.
That any other vial in the same lot has the same composition. One vial was tested. Within-lot vial-to-vial variation in this index has a median of 0.28 pp and a 90th percentile of 0.74 pp.
That any other lot from the same supplier has the same composition. Batch-to-batch variation is larger than within-batch variation for every supplier here.
That the material is suitable for administration to a human or an animal. These are research compounds. No result on this site is a safety assessment and the index takes no position on use.
That the material was manufactured by the supplier that sold it. Contract synthesis is normal in this market and twenty-nine batches in the index fingerprint to a bulk from a different company than the one named on the label.

Section 6

Annotations 3

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.

oxidation_ladder28 Aug 2024

If the dominant species is an oxidation product the finding is about handling; if it is a deletion or a diastereomer the finding is about synthesis. On this record it is diketopiperazine (−18 Da), which settles the question.

buyer_sourced28 Aug 2024

Independently purchased, at the submitter's own cost, forwarded without the supplier's involvement. That is the definition and this record meets it.

selection_bias28 Aug 2024

Provenance handles supplier selection. It does not handle submitter selection, which is the larger confounder and the one the index cannot measure.

Section 7

Related records

Same batch — lot BCH-2407-M7005 n=7

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2024-005556	BCH-2407-M7005	Janoshik	2024-Q3	99.02	6.99	—	Buyer-sourced	1	MARGINAL
AX-2024-005557	BCH-2407-M7005	PeptideMeter	2024-Q3	99.32	6.98	88.7	Buyer-sourced	2	MARGINAL
AX-2024-005558	BCH-2407-M7005	PeptideMeter	2024-Q3	99.26	6.86	97.7	Buyer-sourced	2	FAIL
AX-2024-005559	BCH-2407-M7005	PeptideMeter	2024-Q3	98.89	6.80	—	Buyer-sourced	1	FAIL
AX-2024-005560	BCH-2407-M7005	Janoshik	2024-Q3	99.29	7.11	—	Laboratory-retained	1	MARGINAL
AX-2024-005562	BCH-2407-M7005	Janoshik	2024-Q3	99.42	6.83	—	Buyer-sourced	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Selank records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043000	GGPeps	GGPE-2602-G3499	PeptideMeter	2026-Q3	98.68	8.10	89.6	Buyer-sourced	1	FAIL
AX-2026-042924	GGPeps	GGPE-2603-J2151	Medutest	2026-Q3	99.18	8.75	100.1	Buyer-sourced	0	PASS
AX-2026-042987	GGPeps	GGPE-2601-J2834	Janoshik	2026-Q2	99.69	9.52	92.5	Buyer-sourced	0	PASS
AX-2026-042770	ERP	ERP-2605-M9199	Janoshik	2026-Q2	99.47	6.15	101.1	Buyer-sourced	0	PASS
AX-2026-042762	ERP	ERP-2605-M9199	Janoshik	2026-Q2	99.30	6.05	89.8	Buyer-sourced	1	MARGINAL
AX-2026-042992	GGPeps	GGPE-2601-J2834	Janoshik	2026-Q2	99.67	9.70	107.2	Buyer-sourced	0	PASS
AX-2026-042985	GGPeps	GGPE-2601-J2834	Janoshik	2026-Q2	99.64	9.27	105.7	Buyer-sourced	0	PASS
AX-2026-042993	GGPeps	GGPE-2601-J2834	Janoshik	2026-Q2	99.92	9.59	—	Supplier-supplied	0	PASS

Other recent BCH records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043691	BPC-157	BCH-2603-L7768	Janoshik	2026-Q3	98.66	5.12	—	Supplier-supplied	1	MARGINAL
AX-2026-043693	BPC-157	BCH-2603-L7768	PeptideMeter	2026-Q3	97.82	5.21	94.9	Buyer-sourced	0	FAIL
AX-2026-043686	BPC-157	BCH-2603-L7768	VendorInvestigate	2026-Q3	97.64	5.27	—	Buyer-sourced	0	FAIL
AX-2026-043695	BPC-157	BCH-2603-L7768	Janoshik	2026-Q3	97.61	5.42	—	Buyer-sourced	0	FAIL
AX-2026-043726	N-Acetyl Semax Amide	BCH-2602-E8475	Janoshik	2026-Q3	97.89	9.67	104.2	Buyer-sourced	0	FAIL
AX-2026-043688	BPC-157	BCH-2603-L7768	Janoshik	2026-Q3	97.94	5.56	—	Buyer-sourced	0	FAIL
AX-2026-043658	BPC-157	BCH-2603-G6644	Janoshik	2026-Q3	98.45	4.37	101.8	Supplier-supplied	0	PASS
AX-2026-043692	BPC-157	BCH-2603-L7768	VendorInvestigate	2026-Q3	97.60	5.61	—	Buyer-sourced	0	FAIL