21332
An intermediate GTX2 , 3 - aldehyde was first synthesized by activating the NH2 group of the 2nd and 8th amino acid residues with three different aldehydes and two artificial complete antigens GTX2 , 3 - aldehyde - bovine serum albumin ( BSA ) and GTX2 , 3 - aldehyde - keyhole limpet hemocyanin ( KLH ) were then prepared by cross - linking the intermediate with BSA or KLH .
 Chemical: GTX2 , 3 - aldehyde; Chemical: NH2; Chemical: amino acid; Chemical: aldehydes; Chemical: GTX2 , 3 - aldehyde; Chemical: GTX2 , 3 - aldehyde
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: GTX2 , 3 - aldehyde; Chemical: NH2; Chemical: amino acid; Chemical: aldehydes; Chemical: GTX2 , 3 - aldehyde; Chemical: GTX2 , 3 - aldehyde