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: Pretreatment with L - NOArg and L - NIL but not 7 - NI , significantly increases antihyperalgesic activity both HOE 140 and des Arg10 HOE 140 .
### Output Text:
Pretreatment with L - NOArg and L - NIL but not 7 - NI , significantly increases antihyperalgesic activity both <span class="chemical">HOE 140</span> and <span class="chemical">des Arg10 HOE 140</span> . 