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: RATIONALE : NG - nitro - L - arginine ( L - NOARG ) , an inhibitor of nitric - oxide synthase ( NOS ) , induces catalepsy in mice .
### Output Text:
RATIONALE : <span class="chemical">NG - nitro - L - arginine</span> ( <span class="chemical">L - NOARG</span> ) , an inhibitor of <span class="chemical">nitric - oxide</span> synthase ( NOS ) , induces catalepsy in mice . 