1524
Rats were exposed to BCNU on embryonic day 15 and melatonin was given until delivery .
 Chemical: BCNU; Chemical: melatonin
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: BCNU; Chemical: melatonin