24042
Five new diketopiperazine derivatives , ( 3Z , 6E ) - 1 - N - methyl - 3 - benzy lidene - 6 - ( 2S - methyl - 3 - hydroxypropylidene ) piperazine - 2 , 5 - dione ( 1 ) , ( 3Z , 6E ) - 1 - N - methyl - 3 - benzylidene - 6 - ( 2R - methyl - 3 - hydroxypropylidene ) piperazine - 2 , 5 - dione ( 2 ) , ( 3Z , 6Z ) - 3 - ( 4 - hydroxybenzylidene ) - 6 - isobutylidenepiperazine - 2 , 5 - dione ( 3 ) , ( 3Z , 6Z ) - 3 - ( ( 1H - imidazol - 5 - yl ) - methylene ) - 6 - isobutylidenepiperazine - 2 , 5 - dione ( 4 ) , and ( 3Z , 6S ) - 3 - benzylidene - 6 - ( 2S - but - 2 - yl ) piperazine - 2 , 5 - dione ( 5 ) , were isolated from the marine - derived actinomycete Streptomyces sp .
 diketopiperazine, ( 3Z , 6E ) - 1 - N - methyl - 3 - benzy lidene - 6 - ( 2S - methyl - 3 - hydroxypropylidene ) piperazine - 2 , 5 - dione, ( 3Z , 6E ) - 1 - N - methyl - 3 - benzylidene - 6 - ( 2R - methyl - 3 - hydroxypropylidene ) piperazine - 2 , 5 - dione, ( 3Z , 6Z ) - 3 - ( 4 - hydroxybenzylidene ) - 6 - isobutylidenepiperazine - 2 , 5 - dione, ( 3Z , 6Z ) - 3 - ( ( 1H - imidazol - 5 - yl ) - methylene ) - 6 - isobutylidenepiperazine - 2 , 5 - dione, ( 3Z , 6S ) - 3 - benzylidene - 6 - ( 2S - but - 2 - yl ) piperazine - 2 , 5 - dione
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 diketopiperazine, ( 3Z , 6E ) - 1 - N - methyl - 3 - benzy lidene - 6 - ( 2S - methyl - 3 - hydroxypropylidene ) piperazine - 2 , 5 - dione, ( 3Z , 6E ) - 1 - N - methyl - 3 - benzylidene - 6 - ( 2R - methyl - 3 - hydroxypropylidene ) piperazine - 2 , 5 - dione, ( 3Z , 6Z ) - 3 - ( 4 - hydroxybenzylidene ) - 6 - isobutylidenepiperazine - 2 , 5 - dione, ( 3Z , 6Z ) - 3 - ( ( 1H - imidazol - 5 - yl ) - methylene ) - 6 - isobutylidenepiperazine - 2 , 5 - dione, ( 3Z , 6S ) - 3 - benzylidene - 6 - ( 2S - but - 2 - yl ) piperazine - 2 , 5 - dione