NAD(P)H/quinone acceptor oxidoreductase type 1 (QR1) protects cells from cytotoxic and neoplastic effects of quinones though two-electron reduction. Kinetic experiments, docking, and binding affinity calculations were performed on a series of structurally varied quinone substrates. A good correlation between calculated and measured binding affinities from kinetic determinations was obtained. Th...

Representative strains of each of the named species of Legionella were examined for isoprenoid quinones by reverse-phase thin-layer chromatography. All strains contained three or more ubiquinones (Q9, Q10, Q11, Q12, Q13) which were useful for placing the species into one of three distinct groups. Group 1 contained L. longbeachae, L. bozemanii, L. dumoffi, and L. gormanii; group 2 contained only...

An amperometric biosensor based on the enzyme polyphenoloxidase (PPO), which makes the bioelectrocatalysis of phenolic compounds, was developed and optimized using cathecol as substrate. Polyethersulphone membranes were used for enzyme immobilization. Polyphenoloxidase oxidizes monophenols (cresolase activity) and diphenols (catecholase activity) into the corresponding o-quinones; the o-quinone...

Fully substituted quinones including some naturally occurring oxyquinones acted as inhibitors o f yeast gluta­ thione reductase (EC 1.6.4.2). They were competitive, mixed or uncompetitive inhibitors for N A D PH , possess­ ing K j in the range o f 1 2 0 0 |iM and uncompetitive in­ hibitors for glutathione. Rhein (4,5-dioxy-9,10-anthraquinone-2-carbonic acid) and 9,10-phenanthrenequinone were th...

Formation of the 2,3-dicyanohydroquinone (3) can be rationalised in terms of preferential addition of cyanide at the most electron deficient unsubstituted carbon of the cyanoquinone (2 ) in the same way as alcohols and other nucleophiles add to the 3-position of the acylquinone ( 8 ) [4], However, such an argu­ ment could not be applied to the formation of the dihydroxylamine (6 ). Hence, eithe...

Phytochemical studies of leaves and roots of the plant EchiumpycnanthumPomel (family Boraginaceae) revels thepresence of Flavonoids, Tannins, Quinones, Alkaloids, Saponins, Stérols and absence of Anthocyanes and Coumarines.

Increasing the polyunsaturated fatty acid (PUFA) composition of milk is acknowledged to be of benefit to consumer health. Despite the high PUFA content of forages, milk fat contains only about 3% of PUFA and only about 0.5% of n-3 fatty acids. This is mainly due to intensive lipid metabolism in the rumen (lipolysis and biohydrogenation) and during conservation (lipolysis and oxidation) such as ...

Nanostructured materials with tunable structures and functionality are of interest in diverse areas. Herein, metal ions coordinated quinones through metal-acetylacetone coordination bonds to generate a class structurally tunable, universally adhesive, hydrophilic, pH-degradable materials. A library metal-quinone networks (MQNs) is produced from five model quinone ligands paired nine ions, leadi...