28883
Three cyclopropane analogs were prepared efficiently starting from 4 - benzyloxybenzaldehyde , and evaluated for their binding to estrogen receptors ER alpha and ER beta .
 Chemical: cyclopropane; Chemical: 4 - benzyloxybenzaldehyde; Chemical: estrogen
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: cyclopropane, 4 - benzyloxybenzaldehyde, estrogen 
Answer:
 Chemical: cyclopropane; Chemical: 4 - benzyloxybenzaldehyde; Chemical: estrogen