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: NRA0160 and clozapine significantly induced catalepsy in rats , although their effects did not exceed 50 % induction even at the highest dose given .
### Output Text:
<span class="chemical">NRA0160</span> and <span class="chemical">clozapine</span> significantly induced catalepsy in rats , although their effects did not exceed 50 % induction even at the highest dose given . 