Quinones functions

Zayats M, Katz E, Baron R, Willner I. 2005. Reconstitution of apo-glucose dehydrogenase on pyrroloquinoline quinone-functionalized Au nanoparticles yields an electrically contacted hiocatalyst. J Am Chem Soc 127 12400-12406. 

This enzyme makes use of the novel cofactor TTQ (tryptophan tryptophyl quinone) which contains an ortho-quinone functional array. The substrate forms an imine... 

Further evidence for the presence of quinone functions was presented by Garten and Weiss 93). 

Routes to benzo-fused derivatives of 1,4-dioxanes, 1,4-oxathianes and 1,4-dithianes make use of anions or dianions of the appropriate 1,2-disubstituted benzene. An alternative approach to the synthesis of 1,4-benzodioxanes involves Diels-Alder addition reactions of alkenes across the quinone function of 1,2-benzoquinones, e.g. (352) — (353). 

Doxombicin (Adriamycin ) is an important chemotherapeutic agent. However, it suffers from dose-limiting cardiomyopathy. It thus represents an attractive building block for the preparation of an MGd conjugate. In particular, the easy-to-reduce quinone functionality could provide an additional site for electron capture (from, e.g., NAD(P)H), which in turn could aid in the production of ROS [77-87],... 

We have synthesized molecules with regioisomeric variations in the placement of the nitro group and with quinone functionality,31 heterocyclic and porphyrin-based molecules,32 pyridine-based molecules,33 molecules with diazonium alligator clips,34 biphenyl- and fluorenyl-based molecules,35 nitrile terminated molecules,36 previously-published molecules with improved syntheses,37 and combinatorial methods of synthesizing tens to hundreds of molecule types at a time.38... 

Antitumor agents mitomycin A (61 A) and mitomycin C (61C) contain a latent quinone functionality, which is exposed by reductive activation and elimination of a glycoside or an alcohol followed by opening of the aziridine ring. These quinone methides then react with nucleic acids to form bis-adducts.103 The reductive activation of mitomycins provides selectivity in targeting solid tumors, because this is favored in the oxygen-deprived environment of tumor cells, and inhibited by the oxygen-rich environment of healthy tissues.107... 

Quinone functionalities appear as components in organic switches, and the coupled redox chemistry of quinones with transition metals may provide the basis for an organotransition metal switch [164]. A system that may exhibit light-induced switching was studied in the example of the quionone-tethered form of Ru(bipy)3+ [242], but the charge-separated state that results from the Ru(II) —Q electron transfer is short-lived [164,242],... 

Anthraquinone-based bolaphile 30 (included in this nonionic section for convenience) was created in order to locate the quinone moiety within the center of a membrane however, stable membrane formation was prevented due to steric considerations. It was possible to integrate this quinoid bolaphile into other host membranes, such as dihexyldecyl-phosphate. The absence of borohydride reduction supports the premise that the quinone functionality is located at the midpoint of the host membrane wall.35 Structures 29, 30, and 31 were synthesized as... 

A variety of oxygen-containing functional groups have been proposed to exist in carbon black (17). The best documented of these are the phenolic hydroxy and quinone functions. These also are the most likely groups capable of entering into reactions with hydrocarbon polymers. The presence of carboxylic acid and lactone groups also appears well established (69-71), but is not universally accepted (72). 

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