17737
Here we show for the first time a 3D quantitative structure - activity relationship ( 3D - QSAR ) for a series of aza - PCU - derived compounds with activity at the sigma - 1 ( sigma 1 ) receptor .
 Chemical: aza - PCU
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: aza - PCU