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: As inhibitors of isolated L1210 TS , CB 3717 di - , tri - , tetra - and pentaglutamate are 26 - , 87 - , 119 - and 114 - fold more potent than CB 3717 , respectively , and their formation may , therefore , be an important determinant of CB 3717 cytotoxicity .
### Output Text:
As inhibitors of isolated L1210 TS , CB 3717 di - , tri - , tetra - and pentaglutamate are 26 - , 87 - , 119 - and 114 - fold more potent than <span class="chemical">CB 3717</span> , respectively , and their formation may , therefore , be an important determinant of <span class="chemical">CB 3717</span> cytotoxicity . 