20176
CoMFA contour analysis revealed that bulky substitution around the meta position of the phenyl ring , as well as optimal substitution ( para ) of the phenyl ring , could produce molecules with improved activity .
 phenyl, phenyl
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 phenyl, phenyl