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: In conclusion mitochondrial toxicity is an early common event both in paclitaxel and cisplatin induced neurotoxicity .
### Output Text:
In conclusion mitochondrial toxicity is an early common event both in <span class="chemical">paclitaxel</span> and <span class="chemical">cisplatin</span> induced neurotoxicity . 