Dinitrobenzene sulfonic acid

Sodium hydroxyalkanesulfonates may be determined in the presence of an unsaturated hydrocarbon, including sodium alkenesulfonate. The sulfonates are converted to the free sulfonic acids using a slight excess of 2,4-dinitrobenzene-sulfonic acid. The hydroxyl group of the sulfonic acid liberated is acetylated in ethyl acetate solution by a known excess of acetic anhydride. The unconsumed anhydride is hydrolyzed by a pyridine-water mixture and the acids titrated potentiometrically with standard sodium hydroxide solution. The hydroxy-alkanesulfonate content is calculated after correction for any traces of acidity or alkalinity in the original sample. 

I. Treatment of Crohn s Disease Using Dinitrobenzene Sulfonic Acid-induced Inflammatory Bowel Syndrome... 

Wistar-derived male or female rats weighing 200 g, which fasted 24 hours, were used. Distal colitis was induced by intracolonic instillation of 2,4-dinitrobenzene sulfonic acid, which was injected to ensure that the solution remained in the colon. The Step 3... 

T. spiralis Infection ameliorates experimental (dinitrobenzene sulfonic acid = DNBS)-induced colitis in mice, with a down-regulation of myeloperoxidase (MPO) activity in colonic tissue linked to an emerging Th2-type immune response characterized by high lL-4 and lL-13 production by spleen cells in T. spiralis infected mice (Khan et al. 2002). 

Edwards and colleagues have reported derivatization with 2,4-dinitrobenzene sulfonic acid, a procedure useful for quantification of a number of phenylethylamines, to be unsuitable for analysis of HA. However, Doshi and Edwards discovered that 2,6-dinitro-4-trifluoromethyl benzenesulfonic acid (DNTS) reacts readily with catecholamines, histamines, and related biogenic amines with very suitable properties for GC-ED. Formation of the trifluoroacetyl, trimethylsilyl, and heptafluoro butyryl derivatives of HA for GC have been reported, but these compounds have been found to be unsuitable for quantification of HA because of excess tailoring. 

A simple test for free epoxy groups, either in epoxy monomers or in only partially reacted resins, is the reaction with 2.4-dinitrobenzene sulfonic acid. In the presence of piperazine, the resulting ester gives an intensive yellow coloration. For this test, about 0.5 g of the sample is dissolved in a few ml of dioxane, and then a 1 % solution of 2.4-dinitrobenzene sulfonic acid in dioxane is added. After about 1 hr, add a 1 % solution of piperazine in dioxane. The yellow color is specific for free epoxy groups. 

Mazzon E, Dugo L, Li JH et al. GPI 6150, a PARP inhibitor, reduces the colon injury caused by dinitrobenzene sulfonic acid in the tat. Biochem Pharmacol 2002 64 327-37. 

Dinitrobenzene sulfonic acid (DNBSyethanol trinitrobenzene sulfonic acid (TNBSyethanol oxazolone... 

In animals sensitized to DNCB, an intravenous injection of a sodic solution of dinitro-benzensulfonic acid induces a complete inhibition of the contact reaction, but this is only temporary. Contrary to the injection of the dinitrobenzene sulfonic acid which produces a complete but temporary tolerance, the injection of simple DNCB does not induce a complete inhibition but only a decrease in the reaction (Frey and Geleik, 1962 Frey and de Weck, 1964 and de Weck and Frey, 1966). 

Epoxy groups have also been determined spectrophotometrically using 2,4 dinitrobenzene sulfonic acid [66] and by the Zeisel method [67-69]. 

Fig. 12.1. Some active molecules used for the haptenation of antibodies. In (a) /i-aminobenzenearsonic acid or A -(4-aminobenzoyl)-L-glutamic acid are diazotized (according to Table 12.4) and reacted separately with 4-hydroxyphenylisothiocyanate to yield ars-azo-hydroxyphenylisothiocyanate (RAPITC) and glut-azo-hydroxyphenyl-isothiocyanate (GAPITC), respectively, which differ in R. 2,4-Dinitro-l-fluorobenzene and 2,4-dinitrobenzene sulfonate are presented in (b).

The primary site of electrophilic attack on 5(4//)-oxazolones is at position C-4. The oxazolones are activated by deprotonation. For example, a variety of 2,4-disubstituted-5(4.H)-oxazolones (80) react with l-fluoro-2,4-dinitrobenzene and sodium carbonate to give 2,4,4-trisubstituted products <88CB67>. When the products are refluxed in methanol containing a catalytic amount of p-toluene-sulfonic acid, they rearrange to 1-hydroxyindazoles (81) (Scheme 24). Apparently, under certain conditions the site of electrophilic attack may be diverted to the 2 position <93TL3907>. Methylene chloride solutions of a, -unsaturated aldehydes, ketones, and esters containing a catalytic amount... 

Salh et al. also showed that curcumin is able to attenuate colitis in the dinitrobenzene (DNB) sulfonic acid-induced murine model of colitis. When given before the induction of colitis, it reduced macroscopic damage scores, NF-kB activation, and myeloperoxidase activity, and it attenuated the DNB-induced message for IL-ip. Western blotting analysis revealed a reproducible DNB-induced activation of p38 MAPK in intestinal lysates detected by a phosphospecific antibody. This signal was significantly... 

The polymer is treated for 4 hours at 80 °C with l-fluoro-2,4-dinitrobenzene in an ethanol hydrogen carbonate medium. After washing out the excess of reagent, the dinitrophenyl group introduced is measured spectrophotometrically at 430 nm after dissolution of the derivatised polymer in methane sulfonic acid. 

Arylation with l-fluoro-2,4-dinitrobenzene (Sanger s reagent FDNB) and trinitrobenzene sulfonic acid was outlined in Section 1.2.4.2.2. FDNB also reacts with cysteine, histidine and tyrosine. 

Trinitrodipheny Isulfone, crysts (from glac acet ac), mp 196—97° was prepd by heating 4-chloro-rl,3-dinitrobenzene or 2,4-dinitrophenyl-p-toluenesulfonate with Na 3-nitrobenzene-l-sulfinate in aq ale (Refs 1 St 3) 3,5,4 TrinitrodiphenyIsulfone, ndls, mp 199° prepd by heating 3 nitrophenyI-(4-nitrophenyl)-sulfone with a mixt of fuming nitric acid 8c sulfuric acid at 150°(Refs 2St4)... 

SeAt reactions proceed much more slowly with pyridine than with benzene. They usually demand drastic conditions and occur exclusively at the 3-position [47]. The reactivity of pyridine is comparable to that of nitrobenzene ( 10 relative to benzene). In S Ar reactions occuring in strongly acidic media (nitration, sulfonation), this reactivity is similar to that 1,3-dinitrobenzene (< 10" ). The basicity of the pyridine nitrogen is crucial in deciding whether the S Ar reactions in an acid medium involve the free pyridine base or the further deactivated pyridinium ion for instance, pyridines with a pX > 1 are nitrated via the protonated species, while in the case of pyridines with a pX > 2.5, the free base is involved. As expected, donor substituents increase the S Ar reactivity. 

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