17388
The antioxidant assays showed that BIWS - 4b exhibited good activities , including free radicals scavenging effects , ferrous ion - chelating ability and reducing power .
 Chemical: ferrous
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: ferrous