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: Allopregnanolone ( 3alpha - hydroxy - 5alpha - pregnan - 20 - one ) , pregnanolone ( 3alpha - hydroxy - 5beta - pregnan - 20 - one ) and ganaxolone ( a synthetic derivative of allopregnanolone 3alpha - hydroxy - 3beta - methyl - 5alpha - pregnan - 20 - one ) were tested for their ability to suppress the expression ( anticonvulsant effect ) and development ( antiepileptogenic effect ) of cocaine - kindled seizures in male , Swiss - Webster mice .
### Output Text:
<span class="chemical">Allopregnanolone</span> ( <span class="chemical">3alpha - hydroxy - 5alpha - pregnan - 20 - one</span> ) , <span class="chemical">pregnanolone</span> ( <span class="chemical">3alpha - hydroxy - 5beta - pregnan - 20 - one</span> ) and <span class="chemical">ganaxolone</span> ( a synthetic derivative of <span class="chemical">allopregnanolone</span> <span class="chemical">3alpha - hydroxy - 3beta - methyl - 5alpha - pregnan - 20 - one</span> ) were tested for their ability to suppress the expression ( anticonvulsant effect ) and development ( antiepileptogenic effect ) of <span class="chemical">cocaine</span> - kindled seizures in male , Swiss - Webster mice . 