Über die Dioxymaleinsäureoxydase

Abstract

The oxidation of dioxymaleic acid is not a function of polyphenol oxidase or ascorbic acid oxidase; the latter enzyme does not occur in most plants. The juice of the plants examined remained active in the refrigerator for some time; in some cases activity increased in storage. Juice purified by dialysis became inactive after a few hrs. A decrease of the dioxymaleic acid oxidase in the plant tissue is often observed in storage. The dioxymaleic acidoxidase prepd. from various plants behaved differently toward cyanides: total inhibition[long dash]Rumex acetosa, Cucumis sativus, Beta vulgaris, et al.; partial inhibition[long dash]Nasturtium officinale, Lolium perenne, Daucus carota et al.; activation[long dash]Brassica oleracea, Tragopogon porrifolius and Solanum tuberosum. Ascorbic acid inhibits the dioxymaleic acid oxidase.