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Guided by docking study , we then transformed compound 3 into a potent lead compound 4a by changing sulfonamide group to amide .
 Chemical: sulfonamide; Chemical: amide
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: sulfonamide; Chemical: amide