Compound Names, Synonyms, Sequences and CAS Identifiers
To match a compound across a paper, a specification and a vial, compare the sequence or structure, modifications and supplied form. A synonym can point you to the right record. A CAS Registry Number identifies a registered substance. Neither establishes which material is in a particular lot.
Build the identity record
| Field | Check |
|---|---|
| Canonical name | Which defined entity is intended? |
| Synonyms | Does each alias refer to that same entity? |
| Sequence or structure | Are order, stereochemistry and terminal groups specified? |
| Modification | Is a linker, acetyl group, complex or other change present? |
| Form | Which salt, hydration or oxidation state is supplied? |
| Registry identifier | Does its scope match that exact form? |
| Lot evidence | What measurement connects this container to the specification? |
A one-letter sequence records residue order. In IUPAC notation the N-terminal end is written on the left. Record terminal chemistry, stereochemistry and other modifications explicitly when the match depends on them. The CAS Registry explanation describes the separate role of a substance identifier. [1]
Three catalogue ambiguities worth resolving
For TB-500, Esposito and colleagues identified the N-terminally acetylated fragment Ac-LKKTETQ in the particular preparation they analysed. If another specification gives only “TB-500”, request its sequence and terminal modification before treating the preparations as a match. [2]
For CJC-1295, Jetté and colleagues investigated a defined albumin-reactive construct. On a supplier record, a CJC name with the modification field blank leaves the variant open. The chemistry in that paper cannot fill in the blank for a different product. [3]
The Knockout Labs catalogue includes MT-1 and MT-2 as separate listings. Copy the supplied name and nominal amount into an enquiry, then ask for the exact structure and specification. Assigning a sequence or CAS number from a similar abbreviation could identify a different material.
Resolve a conflict without choosing the convenient field
If a certificate names one entity and its sequence describes another, retain both entries, the report version and the lot code. Ask the issuer which entry is correct and request a revised or explanatory record. Keep the original available so that a later reader can follow the correction.
The mass spectrometry guide explains how to read a reported mass. Use the compound index to locate the appropriate profile and batch documentation to request the evidence linking that entity to the actual lot.
Resolve that identity before using a reference value in a mass-to-molar concentration calculation.
Explore the related evidence
| Resource | Why open it |
|---|---|
| Product Specification and Identity Standards | Check which tests, criteria and quantity basis a specification defines. |
| CJC-1295 With DAC and Without DAC | Resolve the with-DAC and without-DAC naming distinction. |
| Guides & Resources | Choose another scientific, analytical or procurement guide. |
Sources and scope
- IUPAC–IUB: One-letter sequence notation, 3AA-20 to 3AA-21 Sections 3AA-20 and 3AA-21 cover one-letter notation, direction and its limitations.
- Esposito et al. (2012). TB-500 fragment characterisation. Drug Testing and Analysis. Chemical identification of an acetylated thymosin beta-4 fragment in the specific sample studied.
- Jetté et al. (2005). Albumin-linked GRF analogues in rats. Endocrinology. Albumin-reactive growth hormone-releasing factor constructs studied with defined modifications.