2622
Only one flavonoid , luteolin - 3 ' - O - glucuronide was found in all the samples , ranging from 8 . 43mg / g in commercial granulate sample to 1 . 22mg / g in in vitro cultured sample .
 flavonoid, luteolin - 3 ' - O - glucuronide
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 flavonoid, luteolin - 3 ' - O - glucuronide