8632
In drug discrimination experiments in rats trained to discriminate a maximal locomotor activating dose of caffeine , paraxanthine , unlike theophylline , generalized poorly to caffeine suggesting the existence of additional mechanisms other than adenosine antagonism in the behavioral effects of paraxanthine .
 Chemical: caffeine; Chemical: paraxanthine; Chemical: theophylline; Chemical: caffeine; Chemical: adenosine; Chemical: paraxanthine
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: caffeine; Chemical: paraxanthine; Chemical: theophylline; Chemical: caffeine; Chemical: adenosine; Chemical: paraxanthine