2-Aminoethanephosphonic acid

Since the first isolation of 2-aminoethanephosphonic acid (171) from rumen ciliate protozoa,95 related compounds (for example, phosphino-lipid96-97 1 72) in considerable number have been found in Nature, and... 

R2- H,CH3,CH3CH2,/CH3/2CH,/CH3/2CHCH2,CgH5,CgH5CH2 and 2-aminoethanephosphonic acid ... 

In 1959, Horiguchi and Kandatsu discovered 2-aminoethanephosphonic acid (AEP) in ciliated sheep rumen protozoa [1], the simplest natural aminophosphonate. This acid is present in some organisms in remarkably high amounts. Freshly laid eggs contain over 95% of total phosphorus in the phosphonate form, principally as AEP [2]. 

A crystal structure determination of a protected dipeptide derivative of (-)l-aminoethanephosphonous acid showed the (-)aminophosphonous acid to have R stereochemistry. 

Finkelstein, J., The preparation of P-aminoethanephosphonic acid, J. Am. Chem. Soc., 68, 2397, 1946. Kamai, G., and Shugurova, E.L, Amides of dialkylphosphonocarboxylic acids and their derivatives, Dokl. Akad. Nauk SSSR, 79, 605, 1951 Chem. Abstr., 49, 15768c, 1955. 

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