Tetrahydroquinone

Termination of polymerization, 173 Tetrafluoromethane, 32 Tetrahydroquinone quadrupole spectrum, 195... 

Any sulfate ions resulting from oxidation of sulfite should be removed otherwise they will be converted to sulfuric acid in the subsequent procedure and destroy sultone. Ordinarily, 12-13 g. of barium chloride dihydrate is required. The end point of the addition is conveniently determined with tetrahydroquinone indicator used in spot tests on filter paper [cf. Ind. Eng. Chem., Anal. Ed., 9, 331 (1937)]. 

Jansson, K, and V. Jansson. 1991. Induction of mutation in V79 Chinese hamster cells by tetrahydroquinone, a metabolite of pentachlorophenol. Mutat. Res. 260 83-87. 

The tetrahydroquinones referred to above are readily reduced to tetrahydro-l-naphthoquin-4-ol derivatives, the photochemistry of which is also of interest. In solution these materials, 117, undergo intramolecular (2 + 2) photocycloaddition to give products, 118, having the tetracyclo[5.3.0.02-604 2]decane ring skeleton. If their configuration permits, these products immediately convert into hemiacetals, 119. 

Ethyl -2 -hydroxy-1 - (methylmethoxy) -1,2,3,4-tetrahydroquinone, see Alachlor Ethyl mercaptan, see Butvlate. EPTC. Ethylene dibromide, Molinate... 

Chiron et al. (1995) investigated the photodegradation of alachlor (20 mg/L) in distilled water and Ebro River water using an xenon arc irradiation. Photolytic half-lives of alachlor in distilled water and river water were 140 and 84 min, respectively. In distilled water, alachlor completely disappeared after 10 h of irradiation. The major photoproducts were hydroxyalachlor and 8-ethyl-l-methoxymethyl-4-methyl-2-oxo-1,2,3,4-tetrahydroquinone. 

Glushkov VA, Tolstikov AG (2007) Synthesis of substituted 1,2,3,4-tetrahydroquinones by the povarov reaction new potentials of the classical reaction. Russ Chem Rev 77 137-159... 

Place 25 mL of the decolorized filtrate obtained from the Sodium Chloride test (above) into a 125 mL Erlenmeyer flask, and add 1 drop of a 0.5% phenolphthalein solution in 50% ethanol. Add 0.05 N sodium hydroxide, dropwise, until the solution is alkaline to pH paper, and then add 0.002 N hydrochloric acid until the indicator is decolorized. Add 25 mL of ethanol and about 0.2 g of tetrahydroquinone sulfate indicator. Titrate with 0.03 N barium chloride solution to a red endpoint. Make a blank determination. 

Pyrogallic acid Various organic compounds l,4-cyclohexanedione(tetrahydroquinone) 3-alizarinsulfonic acid sodium salt Salicylic acid > 5-suIfosalicylic acid / Ameta Khandia (1982) Chopin-Dumas (1981) Farage Janjic (1981-1, 2, 3) Gupta et al. (1981) Gupta Srinivasulu (1981)... 

Spectrophotometric measurements were conducted at room temperature (22° to 25°C.) in a Cary recording spectrophotometer, model 11, or a Zeiss manual spectrophotometer, PMQ III. Activities of cytochrome oxidase and tetrahydroquinone oxidase were measured with a GME Oxygraph at room temperature according to the method reported previously (5). 

Through the conventional enzyme assay in the ascorbate-cytochrome c system, it was found that the hematin a-globin complex was devoid of either the cytochrome oxidase or the tetrahydroquinone oxidase activity. Adding phospholipids did not alter the activity. 

These observations, especially the practical identity of state VII with the ferricyanide-oxidized form (state VIII), strongly suggest that the hematin a globin complex does not possess any oxygenative property or at least does not show up in the spectral behavior as myoglobin or hemoglobin does. All of these results, however, only show that the reduced form of the complex is autoxidizable but that the oxidized form cannot be reduced by reduced cytochrome c or by tetrahydroquinone. Why the oxidized form in state VII diflFers from that in state I is discussed below. 

Soil Degradation products identified in an upland soil after 80 days of incubation included 7-ethyl-l-hydroxyacetyl-2,3-dihydroindole, 8-ethyl-2-hydroxy-l-(methyl-methoxy)-1,2,3,4-tetrahydroquinone, 2, 6 -diethyl-2-hydroxy-A-(methoxymethyl)aceta-nilide and 9-ethyl-1,5-dihydro-1 -(methoxymethyl)-5-methyl-1,4-benzoxazepin-2-(37/)-one (Chou, 1977). In an upland soil, the microorganism Rhizoctonia solani degraded alachlor to unidentified water soluble products (Lee, 1986). Degradation of alachlor by soil fungi gave 2-chloro-2, 6 -diethylacetanilide, 2,6-diethylaniline, 1-chloroacety 1-2,3-dihydro-7-ethylindole, 2, 6 -diethyl-A-methoxymethylaniline and chloride ions (Tiedje and... 

GaIipeine is a biologically active tetrahydroquinone alkaloid that was first isolated in 1999 from the bark of the Venezuelan shrubby tree Galipea officinalis Hancock (Ruta-ceae). In folk medicine, it was used against fevers and an ethanolic extract of Galipea officinalis bark was tested... 

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