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 penicillin derivatives and amoxicillin alone are known to induce such types of lesions , the amoxicillin component , with or without a potentiating effect of clavulanic acid , might have a major role .
### Output Text:
As <span class="chemical">penicillin</span> derivatives and <span class="chemical">amoxicillin</span> alone are known to induce such types of lesions , the <span class="chemical">amoxicillin</span> component , with or without a potentiating effect of <span class="chemical">clavulanic acid</span> , might have a major role . 