TB-500

Description of TB-500

TB-500 is not a sufficiently precise identity label without sequence confirmation. Esposito and colleagues identified Ac-LKKTETQ, an N-terminally acetylated fragment corresponding to thymosin β4 residues 17–23, in a preparation sold as TB-500 [1]. Full-length thymosin β4 has 43 residues and is not interchangeable with that seven-residue fragment.

Validated salt form, excipients, physical appearance, formulation, and product-specific stability data are not established by the supplied reports.

Overview of Published Research

The cited TB-500 work concerns synthesis and analytical characterization [1]. Chromatographic separation and mass-spectrometric characterization address molecular identity; they do not establish clinical effects or equivalence between materials sold under the same name.

Fragment identity and analytical interpretation

The supplied report uses the sample label “TB500(ThymosinB4)” but does not provide sequence or mass-spectrometric identity data. A name alone cannot resolve whether the material is a fragment, full-length thymosin β4, or another preparation. Fragment-specific findings must not be transferred to the supplied product without appropriate identity confirmation.

Evidence and material limitations

Sequence, terminal modifications, CAS number and molecular mass for this supplied material remain unconfirmed. We therefore do not choose a fragment or full-length specification. Analytical purity in a supplier sample report cannot by itself resolve molecular identity or establish ICU lot traceability.