A simple strategy for the induction of extracellular hydroxyl radical (OH) production by white-rot fungi is presented. It involves the incubation of mycelium with quinones and Fe(3+)-EDTA. Succinctly, it is based on the establishment of a quinone redox cycle catalyzed by cell-bound dehydrogenase activities and the ligninolytic enzymes (laccase and peroxidases). The semiquinone intermediate prod...

The photosensitised degradation of 4-chlorophenol (4-CP) by iron meso-tetrakis(2,6-dichloro-3-sulfophenyl)porphyrin (FeTDCPPS) has been studied in aerated aqueous solution, and is shown to lead to formation of p-benzoquinone (BQ) and p-hydroquinone (HQ) as main photoproducts. In deaerated solution no p-benzoquinone was formed. The photolysis products were identified by high performance liquid c...

Quinones are a class of compounds having substantial toxicity and pharmacological function. This work has produced a derivatization method for quinone detection with high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). Through introducing tags (methoxy) to the quinone structures, the ionization efficiencies of five quinones (p-benzoquinone (B...

Fluorescent proteins undergoing green to red (G/R) photoconversion have proved to be potential tools for investigating dynamic processes in living cells and for photo-localization nanoscopy. However, the photochemical reaction during light induced G/R photoconversion of fluorescent proteins remains unclear. Here we report the direct observation of ultrafast time-resolved electron transfer (ET) ...

BACKGROUND In our previous studies conducted on Ardisia crispa roots, it was shown that Ardisia crispa root inhibited inflammation-induced angiogenesis in vivo. The present study was conducted to identify whether the anti-angiogenic properties of Ardisia crispa roots was partly due to either cyclooxygenase (COX) or/and lipoxygenase (LOX) activity inhibition in separate in vitro studies. METHO...

Two-dimensional (2D) spectral correlation analysis has been employed to interpret the complex spectroelectrochemical data obtained from an electrochemical system undergoing following reactions after electron transfer. The system used was electrochemical reduction of p-benzoquinone (p-BQ) in acetonitrile, which produces anion radicals and dianions at its first and second reduction potentials. Th...

Benzene is metabolized to hydroquinone in liver and subsequently transported to bone marrow for further oxidization to 1,4-benzoquinone (1,4-BQ), which may be related to the leukemia and other blood disorders. In the present study, we investigated the proteome profiles of human primary bone marrow mesenchymal stem cells (hBM-MSCs) treated by 1,4-BQ. We identified 32 proteins that were different...

Quinones are widely distributed substances of often potential toxicological significance. On the other hand, cyclic AMP is known to promote a cell-survival response and to retard apoptosis [Berridge, Tan and Hilton (1993) Exp. Hematol. 21, 269-276]. Therefore the effects of quinones on adenylate cyclase were tested. Adenylate cyclase is rapidly inhibited by quinones, with IC50 values of 40-45 m...

Benzene is a chemical contaminant widespread in industrial and living environments. The oxidative metabolites of benzene induce toxicity involving oxidative damage. Protecting cells and cell membranes from oxidative damage, glucose-6-phosphate dehydrogenase (G6PD) maintains the reduced state of glutathione (GSH). This study aims to investigate whether the downregulation of G6PD in K562 cell lin...

Fenton oxidation is generally inhibited in the presence of a high concentration of chloride ions. This study investigated the feasibility of using benzoquinone (BQ) and hydroxylamine hydrochloride (HA) as Fenton enhancers for the removal of glycerin from saline water under ambient temperature by accelerating the ferric system. It was found that organics removal was not obviously affected by chl...