26830
A series of 1 , 3 , 4 - oxadiazole derivatives containing 1 , 4 - benzodioxan moiety ( 7a - 7q ) have been designed , synthesized and evaluated for their antitumor activity .
 Chemical: 1 , 3 , 4 - oxadiazole; Chemical: 1 , 4 - benzodioxan
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: 1 , 3 , 4 - oxadiazole; Chemical: 1 , 4 - benzodioxan