11805
Hypoxia - selective O6 - alkylguanine - DNA alkyltransferase inhibitors : design , synthesis , and evaluation of 6 - ( benzyloxy ) - 2 - ( aryldiazenyl ) - 9H - purines as prodrugs of O6 - benzylguanine .
 Chemical: O6 - alkylguanine; Chemical: 6 - ( benzyloxy ) - 2 - ( aryldiazenyl ) - 9H - purines; Chemical: O6 - benzylguanine
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: O6 - alkylguanine; Chemical: 6 - ( benzyloxy ) - 2 - ( aryldiazenyl ) - 9H - purines; Chemical: O6 - benzylguanine