18557
Evaluation of difluoromethyl ketones as agonists of the gamma - aminobutyric acid type B ( GABAB ) receptor .
 Chemical: difluoromethyl ketones; Chemical: gamma - aminobutyric acid
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: difluoromethyl ketones; Chemical: gamma - aminobutyric acid