20015
An efficient protocol for synthesis of 3 , 3 ' - diindolylmethanes using recyclable Fe - pillared interlayered clay ( Fe - PILC ) catalyst under aqueous medium has been developed .
 Chemical: 3 , 3 ' - diindolylmethanes; Chemical: Fe; Chemical: Fe
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: 3 , 3 ' - diindolylmethanes; Chemical: Fe; Chemical: Fe