Oxidative stress has been proposed to be one of the main causes of aging and has been implicated in the pathogenesis of many diseases. Sensitivity to oxidative stress can be measured by quantifying survival following exposure to a reactive oxygen species (ROS)-generating compound such as paraquat or juglone. Sensitivity to oxidative stress is a balance between basal levels of ROS, the ability t...

Quinones are plant-derived secondary metabolites that present some anti-proliferation and anti-metastasis effects in various cancer types both in vitro and in vivo. This review focuses on the anti-cancer prospects of plant-derived quinones, namely, aloe-emodin, juglone, β-lapachol, plumbagin, shikonin, and thymoquinone. We intend to summarize their anti-cancer effects and investigate the mechan...

The structures of six inhibitors of prolyl hydroxylase, fibrostatins A, B, C, D, E and F produced by a strain of Streptomyces, were deduced to be 1, 2, 3, 4, 5 and 6, respectively, from chemical and spectroscopic evidence, especially from extensive 13C NMR studies including selective decoupling and low power selective decoupling experiments monitored by 13C-1H long-range couplings. These compou...

In a preliminary note (Daglish & Wokes, 1948) it was shown that the 'apparent vitamin C' of the walnut (Juglan8 regia) (Wokes, Organ, Duncan & Jacoby, 1943) was probably a hydrojuglone derivative. The evidence for this was based upon the findings that solutions of the substance separated by chromatography showed an ultraviolet absorption curve similar to those of reduced acetoxyjuglone and ahyd...

Conditions of oxidative stress may lead to cataract formation. Reaction of certain flavoproteins, the NADH: oxidoreductases, with different quinones is well known to form hydrogen-peroxide. This reaction was investigated to get more information on cataract induction by naphthalene and its quinone metabolites. Protein extracts from bovine lens cortex exhibit "diaphorase" activity, indicated as d...

We report the redox potentials of a set of organic aryl molecules, including quinones, juglone, tyrosine and tryptophan, calculated using a first principles molecular dynamics (FPMD) based method. The hybrid functional HSE06 reproduces the redox potentials spanning from -0.25 V to 1.15 V within an error of 0.2 V, whereas the errors with the BLYP functional are much larger (up to 0.7 V). It is f...

Epidemiological studies on the effects of green tea consumption (Camellia sinensis) have demonstrated a reduction for the risk of age-related diseases. The investigation of the in vivo and in vitro antioxidant properties of an aqueous extract of green tea (GTE) was the aim of the current study. 2,2-Diphenyl-1-picrylhydrazyl (DPPH(•)) and superoxide anion radical (O₂(•-)) assays were used to est...

We have shown that Caenorhabditis elegans lacking the PCM-1 protein repair l-isoaspartyl methyltransferase are more sensitive to oxidative stress than wild-type nematodes. Exposure to the redox-cycling quinone juglone upon exit from dauer diapause results in defective egg-laying (Egl phenotype) in the pcm-1 mutants only. Treatment with paraquat, a redox-cycling dipyridyl, causes a more severe d...