9711
We report our attempts at improving the oral efficacy of low - nanomolar inhibitors of xanthine oxidase from isocytosine series through chemical modifications .
 Chemical: xanthine; Chemical: isocytosine
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: xanthine; Chemical: isocytosine