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: Steroids with the 5 alpha , 3 alpha - or 5 beta , 3 alpha - configurations also produced a dose - dependent delay in the onset of limbic seizures induced by kainic acid ( 32 mg / kg , s . c . ) , but did not completely protect against the seizures .
### Output Text:
<span class="chemical">Steroids</span> with the 5 alpha , 3 alpha - or 5 beta , 3 alpha - configurations also produced a dose - dependent delay in the onset of limbic seizures induced by <span class="chemical">kainic acid</span> ( 32 mg / kg , s . c . ) , but did not completely protect against the seizures . 