The Occurrence of Selenocystathionine in Morinda Reticulata Benth A Toxic Seleniferous Plant

Abstract

Chronic selenosis in Australia has been described in horses and cattle (McCray and Hurwood 1963) from north-western Queensland and in horses (Knott, McCray, and Hall 1958) from the Cape York Peninsula. Ingestion of the seleniferous legume Neptunia amplexicaulis Domin. was implicated in the selenosis in the former instance and in earlier work from this laboratory Peterson and Butler (1967) isolated a seleno-amino acid which accounted for a considerable proportion of the selenium in the plant. The substance was characterized as selenocystathionine which had been shown by Aronow and Kerdel-Vegas (1965) to have pharmacological activity. However, N. amplexicaulis is apparently absent from the Cape York Peninsula, the selenosis being ascribed to ingestion of Morinda reticulata. The work reported in this paper was undertaken to identify the selenium-containing compound(s) in this latter plant species.