22702
Among 12 parabens with linear alkyl chains ranging in length from C1 to C12 , heptylparaben ( C7 ) and pentylparaben ( C5 ) showed the most potent ER alpha and ER beta agonistic activity in the order of 10 ( - 7 ) M and 10 ( - 8 ) M , respectively , and the activities decreased in a stepwise manner as the alkyl chain was shortened to C1 or lengthened to C12 .
 Chemical: parabens; Chemical: alkyl; Chemical: heptylparaben; Chemical: pentylparaben
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: parabens; Chemical: alkyl; Chemical: heptylparaben; Chemical: pentylparaben