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 antinociception after morphine ( 3 . 2 mg / kg ) was increased by co - administration with CNSB002 from 28 . 0 and 31 . 7 % to 114 . 6 and 56 . 9 % reversal of hyperalgesia in the inflammatory and neuropathic models , respectively ( P < 0 . 01 ; one - way analysis of variance - significantly greater than either drug given alone ) .
### Output Text:
The antinociception after <span class="chemical">morphine</span> ( 3 . 2 mg / kg ) was increased by co - administration with <span class="chemical">CNSB002</span> from 28 . 0 and 31 . 7 % to 114 . 6 and 56 . 9 % reversal of hyperalgesia in the inflammatory and neuropathic models , respectively ( P < 0 . 01 ; one - way analysis of variance - significantly greater than either drug given alone ) . 