title: Inhibition of mitochondrial energy-linked reactions by 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), a hydroxamic acid from Gramineae.
abstract: DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) is the main hydroxamic acid isolated from maize extracts. It inhibited reversibly ATP synthesis, Pi-ATP exchange reaction and ATPase activity in submitochondrial particles from bovine heart. Half-maximal effects were obtained with 4, 2, and 6 mM DIMBOA respectively. At higher concentrations it also inhibited mitochondrial electron transport (I50 = 11 mM). Irreversible inactivation of mitochondrial electron transport, Pi-ATP exchange reaction and 8-anilino-1-naphthalene sulfonate energy-dependent fluorescence enhancement was also observed. These effects of DIMBOA on energy-linked mitochondrial reactions may explain the inhibitory action of DIMBOA on several aerobic organisms.
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D048588:Benzoxazines; D002417:Cattle; D004579:Electron Transport / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects*; D010078:Oxazines / Q000494:pharmacology*; D013367:Submitochondrial Particles / Q000187:drug effects* / Q000378:metabolism; D003313:Zea mays / Q000032:analysis
chemical_list: D048588:Benzoxazines; D010078:Oxazines; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C050733:2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one