17476
Water and ethanolic extracts of 16 species of seaweeds collected along the Danish coasts were screened for antioxidant activities using four in vitro antioxidant assays ( 2 , 2 - diphenyl - 1 - picrylhydrazyl radical scavenging activity , reducing power , ferrous ion - chelating and liposome model system ) .
 Chemical: 2 , 2 - diphenyl - 1 - picrylhydrazyl; Chemical: ferrous
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: 2 , 2 - diphenyl - 1 - picrylhydrazyl, ferrous 
Answer:
 Chemical: 2 , 2 - diphenyl - 1 - picrylhydrazyl; Chemical: ferrous