7101
We designed and synthesized four nitrile - based peptidomimetic inhibitors with different N - terminal protective groups and different peptide length , and examined their inhibitory effect on the in - vitro enzymatic activity of 3CL ( pro ) of severe - acute - respiratory - syndrome - coronavirus .
 Chemical: nitrile; Chemical: N
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: nitrile; Chemical: N