26332
Twelve alkyl analogues ( 1 - 12 ) of the high - affinity serotonin transporter ( SERT ) inhibitor 6 - nitroquipazine ( 6 - NQ ) were synthesized and studied using in vitro radioligand competition binding assays to determine their binding affinity ( Ki ) .
 Chemical: alkyl; Chemical: serotonin; Chemical: 6 - nitroquipazine; Chemical: 6 - NQ
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: alkyl; Chemical: serotonin; Chemical: 6 - nitroquipazine; Chemical: 6 - NQ