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: 5 , 7 - dichlorokynurenic acid ( 5 , 7 - DCKA ) , a selective glycine site antagonist , injected in doses of 2 . 5 and 4 . 5 microg / 0 . 5 microl bilaterally , into the rostral region of the striatum , decreased both the haloperidol - induced muscle rigidity ( MMG ) and the enhanced electromyographic activity ( EMG ) .
### Output Text:
<span class="chemical">5 , 7 - dichlorokynurenic acid</span> ( <span class="chemical">5 , 7 - DCKA</span> ) , a selective <span class="chemical">glycine</span> site antagonist , injected in doses of 2 . 5 and 4 . 5 microg / 0 . 5 microl bilaterally , into the rostral region of the striatum , decreased both the <span class="chemical">haloperidol</span> - induced muscle rigidity ( MMG ) and the enhanced electromyographic activity ( EMG ) . 