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: The rats received AChE reactivator pralidoxime - 2 - chloride ( 2PAM ) ( 30 . 0 mg / kg BW ) , anticonvulsant diazepam ( 2 . 0 mg / kg BW ) , A ( 1 ) - adenosine receptor agonist N ( 6 ) - cyclopentyl adenosine ( CPA ) ( 2 . 0 mg / kg BW ) , NMDA - receptor antagonist dizocilpine maleate ( + - MK801 hydrogen maleate ) ( 2 . 0 mg / kg BW ) or their combinations with cholinolytic drug atropine sulfate ( 50 . 0 mg / kg BW ) immediately or 30 min after the single SC injection of DFP .
### Output Text:
The rats received AChE reactivator <span class="chemical">pralidoxime - 2 - chloride</span> ( <span class="chemical">2PAM</span> ) ( 30 . 0 mg / kg BW ) , anticonvulsant <span class="chemical">diazepam</span> ( 2 . 0 mg / kg BW ) , A ( 1 ) - <span class="chemical">adenosine</span> receptor agonist <span class="chemical">N ( 6 ) - cyclopentyl adenosine</span> ( <span class="chemical">CPA</span> ) ( 2 . 0 mg / kg BW ) , <span class="chemical">NMDA</span> - receptor antagonist <span class="chemical">dizocilpine maleate</span> ( + - MK801 hydrogen maleate ) ( 2 . 0 mg / kg BW ) or their combinations with cholinolytic drug <span class="chemical">atropine sulfate</span> ( 50 . 0 mg / kg BW ) immediately or 30 min after the single SC injection of <span class="chemical">DFP</span> . 