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: In group C , AKBR showed a significant decrease at 120 min ( - 40 % ) and at 180 min ( - 49 % ) after the start of hypotension and at 60 min ( - 32 % ) after recovery of normotension , and SGOT , SGPT , LDH and total bilirubin showed significant increases after operation .
### Output Text:
In group C , AKBR showed a significant decrease at 120 min ( - 40 % ) and at 180 min ( - 49 % ) after the start of hypotension and at 60 min ( - 32 % ) after recovery of normotension , and SGOT , SGPT , LDH and total <span class="chemical">bilirubin</span> showed significant increases after operation . 