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Selenocystamine is oxidatively deaminated by pig kidney diamineoxidase. The first product of the reaction is the corresponding cyclized aminoaldehyde, selenocystaldimine, which then undergoes further degradation. The oxidative deamination is thus the first step of a series of cyclic reactions which give rise to extensive cleavage of selenocystamine.

Details are reported for the synthesis of 1,3-thiazane-2-carboxylic acid, or beta-homothiaproline, 3-Bromopropylamine is allowed to react with sodium thiosulfate to give S-sulfo-homocysteamine, which is then split in acidic medium to homocystamine. Homocystamine is reduced by a slight excess of dithioerythritol and allowed to react with sodium glyoxylate. beta-Homothiaproline is then isolated by ion exchange on Dowex 50 and finally obtained in pure crystalline form, with a fairly good yield. Some chemical and chromatographic properties of beta-homothiaproline, in comparison with gamma-homothiaproline (1,3-thiazane-4-carboxylic acid), beta-thiaproline (thiazolidine-2-carboxylic acid) and gamma-thiaproline (thiazolidine-4-carboxylic acid) are described.

In alkaline medium and in the presence of cupric ions selenocystamine undergoes autoxidation and is entirely transformed into selenohypotaurine. Among the different metal ions tested, Fe, Co, Ni, Cu, Ag, Mg, Mn, only cupric ions are effective in catalyzing the reaction. The reaction shows an optimum around pH 13. In most respects the autoxidation of selenocystamine is similar to the alkaline autoxidation of cystamine. Some data on the paper and ion exchange chromatographic behaviour of selenohypotaurine and selenotaurine are reported, as also details for the synthesis of selenotaurine.