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: Forty - three ovarian cancer patients were available for analysis following six cycles of the same PAC - containing regimen : 23 had been supplemented by glutamate all along the treatment period , at a daily dose of three times 500 mg ( group G ) , and 20 had received a placebo ( group P ) .
### Output Text:
Forty - three ovarian cancer patients were available for analysis following six cycles of the same <span class="chemical">PAC</span> - containing regimen : 23 had been supplemented by <span class="chemical">glutamate</span> all along the treatment period , at a daily dose of three times 500 mg ( group G ) , and 20 had received a placebo ( group P ) . 