The title compounds were obtained by deprotonation of 1,2,4-tri-hydroxy-anthra-quinone (purpurin) using sodium hydride followed by reaction with either 1-bromo-propane or 1-bromo-butane. 1,4-Dihy-droxy-2-propoxyanthra-quinone crystallizes as a 1:1 solvate from aceto-nitrile, C17H14O5·CH3CN. The anthra-quinone core of the mol-ecule is essentially planar and both hy-droxy groups participate in in...

Allelopathic chemicals released by plants into the rhizosphere have effects on neighboring plants ranging from phytoxicity to inducing organogenesis. The allelopathic activity of naturally occurring quinones and phenols is primarily a function of reactive radicals generated during redox cycling between quinone and hydroquinone states. We isolated cDNAs encoding two distinct quinone oxidoreducta...

We studied FFA (free fatty acid)-induced uncoupling activity in Acanthamoeba castellanii mitochondria in the non-phosphorylating state. Either succinate or external NADH was used as a respiratory substrate to determine the proton conductance curves and the relationships between respiratory rate and the quinone reduction level. Our determinations of the membranous quinone reduction level in non-...

Etoposide is a topoisomerase II poison that is utilized to treat a broad spectrum of human cancers. Despite its wide clinical use, 2-3% of patients treated with etoposide eventually develop treatment-related acute myeloid leukemias (t-AMLs) characterized by rearrangements of the MLL gene. The molecular basis underlying the development of these t-AMLs is not well understood; however, previous st...

Although the effects of vitamin E on platelet function have been investigated in vivo and in vitro, vitamin E quinone, a natural metabolite of vitamin E, has been virtually overlooked. This oxidized form of vitamin E inhibits platelet aggregation and secretion induced by various aggregating agents more effectively than vitamin E by a magnitude of 5-10-fold. Vitamin E and vitamin E quinone do no...

Although the effects of vitamin E on platelet function have been investigated in vivo and in vitro. vitamin E quinone. a natural metabolite of vitamin E. has been virtually overlooked. This oxidized form of vitamin E inhibits platelet aggregation and secretion induced by various aggregating agents more effectively than vitamin E by a magnitude of 5-1 0-fold. Vitamin E and vitamin E quinone do n...

Recently, the neurotoxicity of dopamine (DA) quinone formation by auto-oxidation of DA has focused on dopaminergic neuron-specific oxidative stress. In the present study, we examined DA quinone formation in methamphetamine (METH)-induced dopaminergic neuronal cell death using METH-treated dopaminergic cultured CATH.a cells and METH-injected mouse brain. In CATH.a cells, METH treatment dose-depe...

Although the effects of vitamin E on platelet function have been investigated in vivo and in vitro. vitamin E quinone. a natural metabolite of vitamin E. has been virtually overlooked. This oxidized form of vitamin E inhibits platelet aggregation and secretion induced by various aggregating agents more effectively than vitamin E by a magnitude of 5-1 0-fold. Vitamin E and vitamin E quinone do n...

Although approved for the treatment of hormone-dependent breast cancer as well as for the prevention of breast cancer in high-risk women, the selective estrogen receptor modulator (SERM) tamoxifen has been associated with an increased risk of endometrial cancer in women. With an understanding of the potential carcinogenic mechanisms of these compounds, SERMs could in principle be designed or se...