8902
N - ( Arylcyclopropyl ) acetamides and N - ( arylvinyl ) acetamides or methyl ureas have been prepared as constrained analogues of melatonin .
 Chemical: N - ( Arylcyclopropyl ) acetamides; Chemical: N - ( arylvinyl ) acetamides; Chemical: methyl ureas; Chemical: melatonin
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 - ( Arylcyclopropyl ) acetamides; Chemical: N - ( arylvinyl ) acetamides; Chemical: methyl ureas; Chemical: melatonin