23697
In addition , structure - activity relationships and other important factors of the flavonoids binding to the active site of xanthine oxidase and cyclooxygenase - 2 were discussed , which is expected for further rational drug design .
 Chemical: flavonoids; Chemical: xanthine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: flavonoids, xanthine 
Answer:
 Chemical: flavonoids; Chemical: xanthine