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: D - Penicillamine caused nephrotic syndrome in 1 patient and milder reversible proteinuria in 3 other patients ; none developed renal insufficiency .
### Output Text:
<span class="chemical">D - Penicillamine</span> caused nephrotic syndrome in 1 patient and milder reversible proteinuria in 3 other patients ; none developed renal insufficiency . 