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: Selective distal tubular epithelial toxicity seems to be responsible for the profound potassium wasting that is a major clinical side effect of treatment with AmB .
### Output Text:
Selective distal tubular epithelial toxicity seems to be responsible for the profound <span class="chemical">potassium</span> wasting that is a major clinical side effect of treatment with <span class="chemical">AmB</span> . 