23857
MC - RR differs from MC - LR , the most studied congener only for one residue ( arginine vs leucine ) , resulting in a ten - fold difference in the acute toxicity in mice .
 Chemical: MC - RR; Chemical: MC - LR; Chemical: arginine; Chemical: leucine
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: MC - RR; Chemical: MC - LR; Chemical: arginine; Chemical: leucine