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 basal MAP of conscious SHR was reduced to a similar extent by prazosin ( - 23 % ( - ) - 26 % MAP ) and rauwolscine ( - 16 % ( - ) - 33 % MAP ) .
### Output Text:
The basal MAP of conscious SHR was reduced to a similar extent by <span class="chemical">prazosin</span> ( - 23 % ( - ) - 26 % MAP ) and <span class="chemical">rauwolscine</span> ( - 16 % ( - ) - 33 % MAP ) . 