9811
Within the series of phytosterol derivatives tested , compound 15 was the most active , displaying potent cytotoxicity against HL - 60 with IC ( 50 ) of 5 . 10 mu mol / L , and most of the active compounds showed selective cytotoxicity against tumor and non - tumor cell lines , especially compound 10 with a safety index of 4 . 42 .
 Chemical: phytosterol
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: phytosterol