25998
For the guanine and adenine adducts with S stereochemistry , a similar but somewhat smaller effect ( factor of ~ 15 ) is observed .
 Chemical: guanine; Chemical: adenine
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: guanine; Chemical: adenine