Cytochromes and some respiratory enzymes in mitochondria from the spadix of Arum maculatum.

5. A Fe2+ ion-ethylenediaminetetra-acetic acid complex can catalyse the oxidative formation of an inhibitor from schradan. 6. A mechanism for the simultaneous oxidation of schradan and reduced triphosphopyridine nucleotide is suggested. 7. The requirements for the conversion of dimefox to an anti-esterase are the same as those for schradan, but the rate of esterase inhibition is much higher. Dimefox is also considerably more toxic than schradan to the locust, but LD60 does not vary with fat-body converting activity.