19530
Using proteome microarray technology , potential substrates of Escherichia coli CobB were screened and nine proteins were identified , including N - hydroxyarylamine O - acetyltransferase ( NhoA ) .
 N - hydroxyarylamine, O
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 N - hydroxyarylamine, O