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: On the other hand , bicuculline , aminophylline and BAY k - 8644 inhibited the anticonvulsive action of loreclezole combined with clonazepam .
### Output Text:
On the other hand , <span class="chemical">bicuculline</span> , <span class="chemical">aminophylline</span> and <span class="chemical">BAY k - 8644</span> inhibited the anticonvulsive action of <span class="chemical">loreclezole</span> combined with <span class="chemical">clonazepam</span> . 