[Copilot]

Ambiguous phosphates (alternatives and mixed) were displaying as % in sequence mode instead of the expected @ symbol used for other ambiguous structural monomers.

Changes

• Updated AmbiguousSequenceItemRenderer.symbolToDisplay to include KetMonomerClass.Phosphate alongside existing CHEM and Sugar checks

// Before: only CHEM and Sugar returned '@'
if (
  this.node.monomer instanceof AmbiguousMonomer &&
  (this.node.monomer.monomerClass === KetMonomerClass.CHEM ||
    this.node.monomer.monomerClass === KetMonomerClass.Sugar)
) {
  return '@';
}

// After: Phosphate now included
if (
  this.node.monomer instanceof AmbiguousMonomer &&
  (this.node.monomer.monomerClass === KetMonomerClass.CHEM ||
    this.node.monomer.monomerClass === KetMonomerClass.Sugar ||
    this.node.monomer.monomerClass === KetMonomerClass.Phosphate)
) {
  return '@';
}

This aligns phosphate display behavior with other structural monomers in sequence view.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Ambiguous phosphates (alternatives and mixed) in sequence shown as % symbol instead of @ symbol</issue_title>
<issue_description>Steps to Reproduce

1. Go to Macro - Sequence mode (clean canvas)
2. Load from KET: Ambiguous phosphates (alternatives and mixed) in sequence shown as % symbol instead of @ symbol.zip

Actual behavior
Ambiguous phosphates (alternatives and mixed) in sequence shown as % symbol instead of @ symbol

Expected behavior
Ambiguous phosphates (alternatives and mixed) in sequence shown as @ symbol

Versions

• Ketcher Version 3.2.0-rc.2 Build at 2025-03-17; 17:37:12
• Indigo Version 1.30.0-rc.1.0-g9bdedaba9-wasm32-wasm-clang-19.0.0
• Chrome Version 134.0.6998.89 (Official Build) (64-bit)
• Win10

Issue found while testing: #5942</issue_description>

Comments on the Issue (you are @copilot in this section)

@SefaBilgii This issue is reproducible

Ketcher Version: 3.7.0-rc.1
OS: MacOs Sequoia Version 15.5
Browser : Chrome Version 138.0.7204.169
Indigo version 1.35.0-rc.1.0</comment_new>

• Fixes Ambiguous phosphates (alternatives and mixed) in sequence shown as % symbol instead of @ symbol #6731

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.