1048
Their structures were elucidated by spectroscopic methods as cyclo - ( Gly - L - Ala ) ( 1 ) , cyclo - ( L - Ala - L - Ala ) ( 2 ) , cyclo - ( L - Pro - Gly ) ( 3 ) , cyclo - ( L - Pro - L - Ser ) ( 4 ) , cyclo - ( L - Ala - trans - 4 - hydroxy - L - Pro ) ( 5 ) , cyclo - ( L - Val - L - Pro ) ( 6 ) , cyclo - ( Gly - L - Tyr ) ( 7 ) , cyclo - ( L - Ala - L - Tyr ) ( 8 ) , cyclo - ( L - Tyr - trans - 4 - hydroxy - L - Pro ) ( 9 ) , 3 - methylhydantoin ( 10 ) and 2 - piperidinone ( 11 ) .
 cyclo - ( Gly - L - Ala ), cyclo - ( L - Ala - L - Ala ), cyclo - ( L - Pro - Gly ), cyclo - ( L - Pro - L - Ser ), cyclo - ( L - Ala - trans - 4 - hydroxy - L - Pro ), cyclo - ( L - Val - L - Pro ), cyclo - ( Gly - L - Tyr ), cyclo - ( L - Ala - L - Tyr ), cyclo - ( L - Tyr - trans - 4 - hydroxy - L - Pro ), 3 - methylhydantoin, 2 - piperidinone
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 cyclo - ( Gly - L - Ala ), cyclo - ( L - Ala - L - Ala ), cyclo - ( L - Pro - Gly ), cyclo - ( L - Pro - L - Ser ), cyclo - ( L - Ala - trans - 4 - hydroxy - L - Pro ), cyclo - ( L - Val - L - Pro ), cyclo - ( Gly - L - Tyr ), cyclo - ( L - Ala - L - Tyr ), cyclo - ( L - Tyr - trans - 4 - hydroxy - L - Pro ), 3 - methylhydantoin, 2 - piperidinone