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: This new case of RPGN in the course of D - penicillamine treatment emphasizes the need for frequent monitoring of renal function and evaluation of urinary sediment and proteinuria in these patients .
### Output Text:
This new case of RPGN in the course of <span class="chemical">D - penicillamine</span> treatment emphasizes the need for frequent monitoring of renal function and evaluation of urinary sediment and proteinuria in these patients . 