24859
A novel series of histamine H4 receptor antagonists based on the pyrido [ 3 , 2 - d ] pyrimidine scaffold : Comparison of hERG binding and target residence time with PF - 3893787 .
 Chemical: histamine; Chemical: pyrido [ 3 , 2 - d ] pyrimidine; Chemical: PF - 3893787
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: histamine; Chemical: pyrido [ 3 , 2 - d ] pyrimidine; Chemical: PF - 3893787