23953
The pair of 26 - trans enantiomers , one of the most potent inhibitors with EC50 of 4 nM and selectivity index ( SI ) of 75000 , was highly effective against a panel of RTIs - resistant strains with single ( Y181C and K103N ) or double ( A17 ) mutations in reverse transcriptase .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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