7447
Solid - phase parallel synthesis based on cross - linked polystyrene and a Wang anchor allowed the low - scale preparation of four small libraries based on the combination of two amino acid residues ( out of Gly , Leu , Phe , Lys , phenylglycine , Tyr , Trp , His , and Arg ) .
 Chemical: polystyrene; Chemical: amino acid; Chemical: Gly; Chemical: Leu; Chemical: Phe; Chemical: Lys; Chemical: phenylglycine; Chemical: Tyr; Chemical: Trp; Chemical: His; Chemical: Arg
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: polystyrene; Chemical: amino acid; Chemical: Gly; Chemical: Leu; Chemical: Phe; Chemical: Lys; Chemical: phenylglycine; Chemical: Tyr; Chemical: Trp; Chemical: His; Chemical: Arg