3969
Comparative study of equimolar doses of gamma - hydroxybutyrate ( GHB ) , 1 , 4 - butanediol ( 1 , 4 - BD ) and gamma - butyrolactone ( GBL ) on catalepsy after acute and chronic administration .
 gamma - hydroxybutyrate, GHB, 1 , 4 - butanediol, 1 , 4 - BD, gamma - butyrolactone, GBL
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 gamma - hydroxybutyrate, GHB, 1 , 4 - butanediol, 1 , 4 - BD, gamma - butyrolactone, GBL