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 pentose phosphate shunt activity of the dapsone - exposed AE RBCs was increased compared to normal RBCs .
### Output Text:
The <span class="chemical">pentose phosphate</span> shunt activity of the <span class="chemical">dapsone</span> - exposed AE RBCs was increased compared to normal RBCs . 