1.3.5- Benzenetriol, from

Hydroxyhydroquinone (24) forms colorless plates from diethyl ether when freshly prepared. It occurs in many plants and trees in the form of ethers, quinonoid pigments, coumarin derivatives, and complex compounds. Sponges from the coastal waters of Florida have been found to contain small amounts of 1,2,4-trihydroxybenzene and traces of 2,2, 4,4, 6,6 -hexahydroxybiplienyl (25) (78). The benzenetriol has also been isolated from tobacco leaves and tar from tobacco smoke (79). Hydroxyhydroquinone has strong reducing properties. Applications have been suggested in the synthesis of agricultural... 

The gallic acid used in the preparation of 1,2,3-benzenetriol can be obtained by microbial degradation of tannins, which are complex combinations of glucose and gallic acid obtained from oak bark and gallnuts. A few other representatives of the many types of naturally occurring derivatives of polyhydric arenols are... 

In a study by Orzechowski et al. (1995), hepatocytes from adult male Wistar rats and NMRI mice were incubated for 1 hour with 0.5 mM 14C-benzene, and the supernatant analyzed for metabolites. Formation of sulfate conjugates of benzene, hydroquinone, and 1,2,4-benzenetriol was also studied in a separate experiment. Mouse hepatocytes produced two metabolites (1,2,4-trihydroxybenzene sulfate and hydroquinone sulfate) that were not found in rat hepatocyte incubations. These sulfate metabolites were found in incubations including benzene, or the metabolites themselves, hydroquinone and 1,2,4-benzenetriol. Mouse hepatocytes were almost three times more effective in metabolizing benzene, compared to rat hepatocytes. This difference was accounted for in the formation of hydroquinone, hydroquinone sulfate, and 1,2,4-trihydroxybenzene sulfate. These in vitro experiments indicate there are both quantitative and qualitative differences in rodent metabolism of benzene. 

Rao (1991) showed that hematin catalyzed the autoxidation of hydroquinone or 1,2,4-benzenetriol in vitro, producing reduced oxygen species that may be responsible for protein or DNA binding after benzene exposure. Further work along this line of research has provided evidence that in vitro, chelates of iron and hydroquinone or 1,2,4-benzenetriol are potent DNA cleaving agents (Rao 1996 Singh et al. 1994), and that 1,2,4-benzenetriol, but not hydroquinone, causes the release of iron from ferritin (Ahmad et al. 1995). 

Benzenetriol or hydroquinone have also been shown to release reactive products from glutamate or DNA in the presence of copper ions (Rao and Pandya 1989). 

Benzene metabolites have also been shown to damage murine hematopoietic cells in vitro (Seidel et al. 1991). In addition, benzene has been shown to decrease mitochondrial respiration and increase superoxide radical production in isolated rat heart mitochondria (Stolze and Nohl 1994). The effects of exposure of HL-60 cells (human promyelocytic leukemic cells) to hydroquinone, />benzoquinonc, or 1,2,4-benzene-triol were studied by Rao and Snyder (1995). The cytotoxic effect of the metabolites on HL-60 cells, measured as cell viability, could be ranked as />benzoquinone>hydroquinone> 1,2,4-benzenetriol, with viability from 50% to 70% after incubation with concentrations up to 100 pM for 4 hours. Basal levels of superoxide anion or nitric oxide production were not affected by incubation of the cells with the metabolites, but in the presence of TPA, each metabolite increased superoxide anion production however, nitric oxide production was increased with hydroquinone and />benzoquinonc, but not 1,2,4-benzenetriol. HL-60 cells showed increased production of hydrogen peroxide after exposure to the three benzene metabolites. This study suggests that benzene metabolites may predispose the cells to oxidative damage by inhibiting or reducing antioxidant mechanisms within the cell. 

Ahmad S, Singh V, Rao GS. 1995. Release of iron from ferritin by 1,2,4-benzenetriol. Chemico-Biological Interactions 96 103-111. 

The reaction should be theimoneutral if there is no net difference, steric or electronic, upon replacing the phenolic hydrogen with a methyl group. From the enthalpies of formation of gas and solid phase trimethoxybenzenes, the enthalpies of reaction are 9.7 kJ mol for the 1,2,3- and —4.0 kJ mol for the 1,3,5-benzenetriol in the gas phase. The solid phase reaction enthalpies are 1.9 kJ moU for the 1,2,3- and 0.4 kJ mol for the 1,3,5-isomer. The enthalpies of reaction per methyl replacement are one-third these values. All... 

The compounds that we have identified from sorghum root extracts other than 1 are 5-ethoxysorgoleone (2), 2,5-dimethoxysorgoleone (3), 2-hydroxy-5-methoxy-3-[(8 Z, 11 Z, 14 Z-)-8, 1114 -heptadecatrienyI]-2,5-cyclohexadiene-1, 4-dione (4), 2-hydroxy-5-methoxy-3-[(8 Z,l rZ)-8, ll -pentadecadienyl]-2,5-cyc-lohexadiene-1,4-dione (5), 2-hydroxy-5-methoxy-3-[(8 Z)-8 -pentadecenyl]-2,5-cyclohexadiene-1,4-dione (6), 2-hydroxy-5-methoxy-3-pentadecyl-2,5-cycIo-hexadiene-1,4-dione, also known as dihydromaesanin (7), 4,6-dimethoxy-2-[(8 Z, 11 Z)-8, 1114 -pentadecatrienyl]-1,3-benzenediol (8), 4-methoxy-6-etho-xy-2-[(8 Z,irZ)-8, ir,14 -pentadecatrienyl]-l,3-benzenediol (9) and 6-ethoxy-3-[(10 Z,13 Z)-10, 13, 16 -heptadecatrienyl]-l,2,4-benzenetriol (10) (Fig. 3). 

The hydrothermolysis (27.5 MPa, 290 - 400 C) of D-fructose furnished 5-hydroxymethyl-2-furaldehyde, furfural, and l,2,4-benzenetriol. The epimeric compounds S3, separable by h.p.l.c., have been isolated in high yields from the reaction of D-glucose with guanosine under physiological conditions. An analysis of the aroma compounds produced on exposure of riramnose to cysteine under roasting conditions (2(X) - 220 C) revealed the presence of ca. 180 compounds, mosdy derivatives of furan, pyrrole, artd thiophene, 125 of which have been identified. ... 

The biodegradation of nitrophenols has been studied extensively because of the wide use of pesticides that contain nitrophenyl groups and because the nitrophenols are used as preservatives for leather. Simpson and Evans (42) isolated a Pseudomonas from soil that was able to grow on 4-nitrophenol with concomitant release of nitrite. Based on evidence from simultaneous adaptation studies they proposed that 4-nitrophenol was converted to hydroquinone. Subsequently, Munnecke and Hsieh (28) detected traces of hydroquinone in the medium when cultures of a soil pseudomonad were grown on 4-nitrophenol. They proposed that hydroquinone was hydroxylated to 1,2,4-benzenetriol as the next step in the metabolic pathway but provided no experimental evidence. Nitrite release was detected during the degradation of a wide range of nitrophenols and nitrobenzoates (20) over the next 20 years, but the mechanism of the reaction remained obscure because the enzyme responsible for the initial reaction could not be studied in cell extracts. 

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