Also available in 1 mL, 50 mg, 100 mg, 200 mg, 500 mg and bulk. Please contact Fisher for quotes. Phosphonoacetate, also known as fosfonet or phosphonacetic acid, belongs to the class of organic compounds known as organic phosphonic acids.Within the cell, phosphonoacetate is primarily located in the cytoplasm. Phosphonoacetate can be biosynthesized from phosphonic acid and acetic acid. Purity ≥98%