This guide shows how to find out what changed on a monomer, who changed it and when, and how to put a deleted monomer back. It continues the example of How to Create or Edit a Monomer, where MeNle had its C-terminal cap corrected and Deg was registered.
Prerequisites: the Administrator role in Biotoolkit Monomers. The Version history entry appears in the navigation menu only for Administrators.
Step 1: Open the Version history
In the navigation menu, click Version history, the clock icon. Four cards summarise the page: the changes of the last 30 days, the monomer most edited, how many deletions are waiting to revive, and the last change. Below them, the report lists one row per archived state, newest first. Each row is a version of a monomer that is no longer current, either because an edit superseded it or because the monomer was deleted.
The default view shows:
| Column | Meaning |
|---|---|
| Before / After | The structure as it was, and the structure that replaced it. After is empty for a deletion. Click a drawing to open it full size in the structure viewer. |
| Monomer | The symbol and the name of the archived state. |
| Version | For an edit, the number before and after, as 1 → 2; for a deletion, the number the monomer had. |
| What happened | A chip: Edited, Deleted, or Deleted, since revived. |
| What changed | For an edit, one tag per field that differs: symbol, name, polymer type, monomer type, natural analog, structure, R-groups. |
| When, By | When the state was archived, and the account that did it. |
| Revive | Present on a deletion that has not been revived. |
The R groups and R groups after columns, as R1: H, R2: OH, and the SMILES and SMILES after columns for a text comparison, are available from the report's Actions menu, under Columns.
The Show chips above the report narrow the list: All, Edits, Deletions, and To revive, which keeps only the deletions that can still be undone. Each chip carries its count, and the To revive card selects the chip of the same name.
Step 2: Read an edit
Type MeNle in the search box and press Enter: the report keeps only the rows of that monomer, newest first. The row of the cap correction reads:
- What happened:
Edited. What changed:R-groups. - Version:
1 → 2. The wrong state was version 1; the live monomer is version 2. - R groups:
R1: H, R2: H. R groups after:R1: H, R2: OH, once the two columns are shown.
A deleted monomer keeps its whole history: the screenshot above shows the deletion of MeNle on top, with its Revive button, and below it the edit that preceded it. The same list, limited to one monomer, is in the Audit tab of its dialog.
Had the structure been changed as well, What changed would carry the tags structure and R-groups, and the Before and After drawings would differ.
Only material changes appear here: symbol, polymer type, monomer type, natural analog, structure and R groups. A change of name or author, or a regenerated drawing, does not create a version. See Versioning and Deletion.
Step 3: Revive a deleted monomer
Suppose a curator deleted Deg by mistake. Select the To revive chip, find the row, and click Revive. The Revive monomer dialog asks Put this monomer back?: confirm with Revive. Reviving is also the answer when a curator is told, on registering a symbol, that it corresponds to 1 deleted monomer: see Versioning and Deletion.
The monomer returns to the library under its original identifier, with a new version number, its original creation date, and the metadata and monomer-set memberships it had. The confirmation reads:
Monomer "Deg" is back, with 0 set membership(s) and 0 metadata row(s) restored.
If a monomer set it belonged to has been deleted in the meantime, the membership cannot be restored and the message says how many were skipped. The row then reads Deleted, since revived and loses its Revive button.
A revive is refused, with the reason, when:
- a live monomer now holds the same symbol, name or structure for that polymer type. Rename or remove that monomer first, or leave the version archived;
- the monomer is public. Public reference data is maintained by Discngine and is never deleted through the application;
- the monomer was already revived, or its most recent archived state is an edit rather than a deletion.
What the log cannot tell you
- The person behind changes made before the 2026.11.02 release. Edits, imports and deletions are attributed to the user who made them, but changes recorded before that release read
Systemin By: they were applied by the Biotoolkit service, which did not record the user then. For an import of that period, the Import history on the Import monomers page records who uploaded the file. - Cosmetic changes. Redrawing the same molecule, or renaming it, leaves no trace here.