Abstract
Up to 1959, all the organic phosphorus compounds isolated from living things had been shown to have the carbon-containing portion of the molecule attached to either oxygen or, less commonly, to nitrogen on the phosphorus atom. It came therefore as a distinct surprise when Horiguchi and Kandatsu29 announced the isolation of a compound having the carbon-to-phosphorus bond, viz. 2-aminoethylphosphonic acid, from ciliated protozoa. Since then several other phosphorus-carbon containing compounds have been detected in nature and isolated. Most of them contain nitrogen also, e.g.