15751
More optimal binding was observed in HBS buffer , and the affinity of the interaction could be slightly increased when the 4 - pyridyl and bis ( 2 - hydroxy - ethyl ) derivatives of lipoic acid were combined in the imprinted layer .
 Chemical: 4 - pyridyl; Chemical: bis ( 2 - hydroxy - ethyl ); Chemical: lipoic acid
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: 4 - pyridyl, bis ( 2 - hydroxy - ethyl ), lipoic acid 
Answer:
 Chemical: 4 - pyridyl; Chemical: bis ( 2 - hydroxy - ethyl ); Chemical: lipoic acid