21730
Our studies suggest that coelenterazine bound within the anaerobic complex might be a mixture of N7 - protonated and C2 ( - ) anionic forms , and that oxygen shifts the equilibrium in favor of the C2 ( - ) anion as a result of peroxy anion formation .
 Chemical: coelenterazine; Chemical: N7; Chemical: C2 ( - ); Chemical: oxygen; Chemical: C2 ( - ); Chemical: peroxy
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: coelenterazine, N7, C2 ( - ), oxygen, C2 ( - ), peroxy 
Answer:
 Chemical: coelenterazine; Chemical: N7; Chemical: C2 ( - ); Chemical: oxygen; Chemical: C2 ( - ); Chemical: peroxy