BPC-157 Acetate + TB-500 Fragment 17-23

1 Identity

Fixed-ratio two-component article: one 15-residue linear peptide free acid isolated as its acetate salt, and one N-acetylated seven-residue peptide free acid. No metal, no acylation in the lipopeptide sense, no cyclization, no disulfide, no non-proteinogenic residue in either chain. Each component's full identity lives on its own record and is cross-referenced from here rather than restated. Two naming failures sit in one title: 'TB-500' is used in this channel for the full-length 43-residue thymosin beta-4 and for this seven-residue fragment, which are different articles differing by about 3.9 kDa, and 'ABP-7' determines no molecule at all. This record specifies Ac-LKKTETQ-OH.

Sequence

Per component, cross-referenced. BPC-157 H-Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val-OH, GEPPPGKPADDAGLV, 15 residues, free acid, isolated as the acetate salt - a counterion held ionically, not an N-acetyl group, and this article is not N-acetyl-BPC-157. Ac-LKKTETQ-OH, seven residues, all-L, the acetyl on the leucine alpha-amino nitrogen and localized by MS/MS rather than inferred from intact mass, C-terminus the free acid of glutamine. That is thymosin beta-4 residues 17 to 23, a fragment and not the parent protein.

Molecular formula

Per component; a mixture has no combined formula and none is written. BPC-157 peptide C62H98N16O22, article C62H98N16O22 . X C2H4O2 with x determined on every lot; Ac-LKKTETQ C38H68N10O14. Neither molecule contains sulfur and neither contains an aromatic ring, so isotope-envelope and chromophore discrimination are both unavailable and the two are separated on mass and retention time alone. Counterion is determined per component: an acetate result on the vial cannot be assigned to a component without prior separation, which matters because one component's identity is defined by its acetate stoichiometry.

Average mass

Per component, on IUPAC 2021 abridged conventional atomic weights: BPC-157 peptide 1419.556 Da, with the salt article carrying no single average mass until x is fixed - mono-acetate 1479.608 at 95.94 percent net peptide, bis-acetate 1539.660 at 92.20 percent, and two protonatable centers setting the chemically sensible ceiling at two moles. Ac-LKKTETQ 889.018 Da. AT A nominal 10 mg plus 10 mg fill, 20 mg total, that is 7.0445 and 11.2484 micromol - a molar ratio of 1.0000 : 1.5968, so equal mass here is a 60 percent molar excess of the smaller component. No single blend 'molecular weight' is printed.

Monoisotopic mass

Per component. BPC-157 1418.7042 Da neutral, [M+H]+ 1419.7115, [M+2H]2+ 710.3594. Ac-LKKTETQ 888.4917 Da neutral, [M+H]+ 889.4989. The acetate has no mass spectrum of its own: acetate dissociates in the electrospray source and is never observed on the peptide ion, so the spectrum of the acetate salt is identical in every particular to that of the free peptide, the trifluoroacetate and the arginate. Counterion determination is a separate release test and is never an inference from the mass spectrum.

Salt / variant note

(1) ratio: none standard. (2) the 'TB-500' fork, the largest naming hazard on this record: full-length thymosin beta-4 at about 4.9 kDa against this 889 Da fragment, sold under one word. (3) BPC-157 salt fork: acetate, trifluoroacetate and the L-arginine salt, mass-spectrometrically indistinguishable, with net peptide content running from 88.7 to 95.9 percent across acetate stoichiometries. (4) 'ABP-7', which resolves to no fixed molecule in the source material. (5) presentation: the channel sells this pairing as a spray, a dose-shaped format, which is an observation about the channel and not a description of the article specified here.

2 Class & testing panel

Form

Fixed-ratio blend

Testing panel

P1 — panel definitionfor both components, run per component and never once for the vial; no P2, P3, P4, P5 or P6 element is present in either chain. The panel is simple and the detection is not: neither component contains a single aromatic residue, so there is no 280 nm chromophore anywhere in this vial and all UV quantitation runs at 214 nm on the amide bond, which is the least selective detection situation in the blend set and the reason mass-spectrometric or amino acid quantitation carries the release rather than LC-UV alone

3 Primary sources & evidence

The index reports the design and provenance of the literature, not a conclusion about effect.

Published literature exists for each component, is graded on that component's record and is cross-referenced rather than restated; the fragment's literature includes its synthesis and analytical characterization as an anti-doping reference standard. None of it is literature about this fixed two-component mixture, and no published specification for one was located.

4 Storage & specification

Storage

White to off-white co-lyophilized solid in Type I amber glass with a PTFE-lined closure, nitrogen headspace, in-pack desiccant, minus 20 degrees C plus or minus 5 degrees C, desiccated and light-protected - a non-sterile laboratory chemical, no sterility claim, and no spray, nasal or other dose-shaped format at any point. Vials equilibrated to ambient before opening, both acetate salts being hygroscopic.

Shelf life

Provisional 24 months at minus 20 degrees C plus or minus 5 degrees C from QA release, being the shorter of the component intervals and provisional pending this company's own data; the blend runs its own protocol and inherits no component study. Stability-indicating attributes: per-component net content, the measured ratio, the aspartyl-to-isoaspartyl rearrangement in the BPC-157 Asp10-Asp11 region which is mass-silent and requires a chromatographic method, water, counterion and any new peak above 0.10 percent. Pulls at 0, 3, 6, 12, 18, 24 and 36 months.