The complexes of zinc, copper and manganese present in ryegrass

Abstract

1. The nature of the complexes of zinc, manganese and copper which occur in ryegrass has been examined as part of a study of the availability of these metals to ruminants.2. Ryegrass labelled with 66Zn was produced by water culture. A large proportion of the Zn could be extracted with aqueous ethanol and with water. The remainder of the Zn was liberated on peptic digestion and on treatment with a fungal cellulase.3. The aqueous ethanolic extract was examined by a combination of gel filtration and thin-layer chromatographic and electrophoretic techniques. The results showed the presence of closely related complexes of Zn of low molecular weight. These were of limited stability and their behaviour was dependent on pH.4. The value of electrophoresis in free solution as a fractionation technique for the soluble forms of Cu, Zn and Mn from ryegrass was demonstrated. Soluble Mn from was found to exist in a single cationic, perhaps non-complexed form, whereas several anionic Cu and Zn complexes were present in closely related forms.