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: Oxprenolol caused decreases of 65 % and 56 % of terbutaline volume of distribution and clearance , respectively , and an increase of 130 % of its AUC .
### Output Text:
<span class="chemical">Oxprenolol</span> caused decreases of 65 % and 56 % of <span class="chemical">terbutaline</span> volume of distribution and clearance , respectively , and an increase of 130 % of its AUC . 