8132
The basis for the use of this complex framework lies in an attempt to constrain one end of the molecule in the " agonist conformation " as was previously described for 3 - oxa - 7 - aza - bicyclo [ 3 . 3 . 1 ] nonanes .
 Chemical: 3 - oxa - 7 - aza - bicyclo [ 3 . 3 . 1 ] nonanes
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: 3 - oxa - 7 - aza - bicyclo [ 3 . 3 . 1 ] nonanes