Flavosemichinon‐Metallchelate: Modelle zur Erklärung der «active site» in den mitochondrialen Flavoenzymen. Zum Verhalten des Riboflavins gegen Metallionen III

The behaviour of half reduced isoalloxazine (flavocoenzyme) systems, riboflavin and analogues, has been studied acidimetrically and spectrophotometrically in aqueous solution, in the presence or absence of non‐redox d‐metal ions. The metal has been found to combine selectively with the flavin semiquinone anion, forming deep red radical chelates with cornproportionation of the ligand system. Colour and reactivity of native metal‐containing flavoenzymes might be explained satisfactorily by this. Reference has been made to biological conclusions advanced elsewhere.