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alpha - Amino - alpha ' - Halomethylketones : Synthetic Methodologies and Pharmaceutical Applications as Serine and Cysteine Protease Inhibitors .
 Chemical: alpha - Amino - alpha ' - Halomethylketones; Chemical: Serine; Chemical: Cysteine
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: alpha - Amino - alpha ' - Halomethylketones; Chemical: Serine; Chemical: Cysteine