20531
The metabolite 4 , ent - 7 alpha - hydroxy - 16 - ketobeyeran - 19 - oic acid , exhibited the most highly potent activity , with EC50 of 3 . 46 nM , whereas the parent compound 1 showed relatively low activity ( EC50 57 . 41 nM ) .
 Chemical: ent - 7 alpha - hydroxy - 16 - ketobeyeran - 19 - oic acid
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: ent - 7 alpha - hydroxy - 16 - ketobeyeran - 19 - oic acid