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: Recently , we demonstrated the hepatoprotective effects of nicotinic acid amide , a selective inhibitor of poly ( ADP - ribose ) polymerase ( PARP ; EC 2 . 4 . 2 . 30 ) on mice suffering from acetaminophen ( AAP ) - hepatitis , suggesting that the AAP - induced liver injury involves a step which depends on adenoribosylation .
### Output Text:
Recently , we demonstrated the hepatoprotective effects of <span class="chemical">nicotinic acid amide</span> , a selective inhibitor of <span class="chemical">poly ( ADP - ribose )</span> polymerase ( PARP ; EC 2 . 4 . 2 . 30 ) on mice suffering from <span class="chemical">acetaminophen</span> ( <span class="chemical">AAP</span> ) - hepatitis , suggesting that the <span class="chemical">AAP</span> - induced liver injury involves a step which depends on adenoribosylation . 