18204
G - rich hexamer ODNs had poor ability to form quadruplex , while X - irradiation of the ODNs induced interstrand exchange reaction at disulfide bond to form ligated 12 mer ODNs , leading to the ready formation of quadruplex due to the entropic effect .
 Chemical: disulfide
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: disulfide