9325
Three stable radicals , in which a radical group is bound in either para or meta position with respect to the pyridine nitrogen atom , were considered .
 Chemical: pyridine nitrogen
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: pyridine nitrogen 
Answer:
 Chemical: pyridine nitrogen