14165
The monoglucuronides and sulfates of epicatechin , 3 ' - O - methylepicatechin , and 4 ' - O - methylepicatechin , respectively , were synthesized as authentic bioanalytical standards .
 monoglucuronides, sulfates, 3 ' - O - methylepicatechin, 4 ' - O - methylepicatechin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 monoglucuronides, sulfates, 3 ' - O - methylepicatechin, 4 ' - O - methylepicatechin