1030
On the basis of the comparable bioactivity of luteolin - based compounds , the presence of an ortho - dihydroxy substitution in the flavone B - ring is supposed to be the structural feature responsible for the antioxidant activity .
 Chemical: luteolin; Chemical: ortho - dihydroxy; Chemical: flavone
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: luteolin; Chemical: ortho - dihydroxy; Chemical: flavone