18640
In view of this , derivatives of aminophosphonic acids , owing to their broad spectrum of biological activities and wide range of applications in the medicinal and agrochemical fields , are very attractive metal - ligand agents that might form biomedical important metal complexes .
 aminophosphonic acids
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 aminophosphonic acids