25413
The ethanol extracts of R . serra leaf and stem were partitioned sequentially into petroleum ether , ethyl acetate , butanol and water fractions , respectively .
 ethanol, petroleum ether, ethyl acetate, butanol
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ethanol, petroleum ether, ethyl acetate, butanol