19344
An array of chemically diverse natural product - rich extracts was selected as a test panel , and a cell - based reporter assay for hypoxia - inducible factor - 1 ( HIF - 1 ) was employed to monitor potential change ( s ) in bioactivity .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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