22192
Compounds 4a , 6a , 7a , 7d and 7g showed potent anticancer activity at low concentrations against most of the used human tumor cell lines comparable with doxorubicin as standard potent anticancer drug ( average log10 GI50 over all cell lines = - 6 . 85 ) .
 doxorubicin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 doxorubicin