24798
Indeed , introduction of an N , N - dimethylamino tail resulted in 4b , which showed almost 50 - fold improvement in inhibition compared to 2a .
 Chemical: N , N - dimethylamino
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: N , N - dimethylamino