Freshly cut slices darken as a result of oxidation of endogenous phenols in reactions catalyzed by polyphenol oxidase. Ascorbic acid, thiols, and other reducing substances prevent enzymic darkening (5, 17). Earlier studies showed that ATP substantially decreased browning in plant tissues, apparently via the reduction of quinones (14). ATP itself is not a reducing agent. The reducing compound is...

The aim of the study was to identify and quantitatively assess of carotenoids and isoprenoid quinones biosynthesized by six different strains of acetic acid bacteria, belonging to genus Asaia, that are common beverage-spoiling bacteria in Europe. Bacterial cultures were conducted in a laboratory liquid culture minimal medium with 2% sucrose. Carotenoids and isoprenoid quinones were investigated...

Fourier transform infrared difference spectroscopy (FTIR DS) is widely used to study the structural details of electron transfer cofactors in photosynthetic protein complexes. In photosynthetic proteins quinones play an important role, functioning as a cofactor in light-driven electron transfer. In photosystem I (PS I) phylloquinone (PhQ) functions as an intermediary in electron transfer. To in...

A series of substituted quinones was alkylated with diethylcadmium. Regiochemistry of addition shifted from quinol formation to conjugate addition as a function of the steric and electronic effects of the substituents.

Lyonia ovalifolia has been used in a folk medicine for the treatment of wounds, cuts, burns, and scabies by different communities Nepal. The present study is intended to evaluate phytochemical constituents leaf plant subject methanol hexane extract screening, GC-MS analysis, HPLC FTIR analysis. Phytochemical screening revealed presence phenolic compounds, flavonoids, glycosides, tannins, xantho...

Two new prenylated quinones, piperogalone (1) and galopiperone (2), and a new prenylated dihydroquinone, hydropiperone (3), were isolated from Peperomia galioides H.B.K (Piperaceae). Hydropiperone exhibited potent antiparasitic activity against three species of Leishmania.

Catechyl monomers 1-electron-oxidize and undergo radical coupling to produce benzodioxane units in lignin. Derived o -quinones Diels–Alder reactions giving oxatricyclo new products, but does this occur lignification?.

Short-chain quinones (SCQs) have been investigated as potential therapeutic candidates against mitochondrial dysfunction, which was largely thought to be associated with the reversible redox characteristics of their active quinone core. We recently reported a library SCQs, some showed potent cytoprotective activity complex I inhibitor rotenone in human hepatocarcinoma cell line HepG2. To better...