2-amino-3-phosphonopropanoic acid2-AP32-amino-3-phosphono-propanoic acid2-amino-3-phosphono-propionic acid2-amino-3-phosphonopropanoic acid2-amino-3-phosphonopropionic acid2-amino-3-phosphopropionic acid2-amino-3-phosprop2-azanyl-3-phosphono-propanoic acidphosphonoalanine