21502
In the course of our ongoing efforts to optimize the antiviral activity of the chromone derivatives , we have been attempting to derivatize the chromone scaffold via introduction of various substituents .
 Chemical: chromone; Chemical: chromone
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: chromone; Chemical: chromone