In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Here , we report a case of prolonged neuromuscular block after administration of suxamethonium leading to the discovery of a novel BCHE variant ( c . 695T > A , p . Val204Asp ) .
### Output Text:
Here , we report a case of prolonged neuromuscular block after administration of <span class="chemical">suxamethonium</span> leading to the discovery of a novel BCHE variant ( c . 695T > A , p . Val204Asp ) . 