12185
Variations at the N1 , C2 , C4 and C5 positions of imidazole were introduced , and the structure - activity relationships of these imidazole inhibitors were also discussed .
 Chemical: imidazole; Chemical: imidazole
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: imidazole; Chemical: imidazole