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: CONCLUSIONS : Although levobupivacaine may have a safer cardiac toxicity profile than racemic bupivacaine , if adequate amounts of levobupivacaine reach the circulation , it will result in convulsions .
### Output Text:
CONCLUSIONS : Although <span class="chemical">levobupivacaine</span> may have a safer cardiac toxicity profile than racemic <span class="chemical">bupivacaine</span> , if adequate amounts of <span class="chemical">levobupivacaine</span> reach the circulation , it will result in convulsions . 