Aniline citrate

Ravdin and Crandall (695) isolated a protein fraction from rat liver which converted homogentisic acid to a jS-keto acid decarboxylated slowly by aniline citrate at 38°C. A second enzyme fraction was obtained which converted this keto acid to acetoacetic acid. The /3-keto acid was isolated as its silver salt and was found also to be a dicarboxylic acid and a /3-diketone, and to give fumaric and acetoacetic acids on hydrolysis. The proposed formulation as fumarylacetoacetic acid (see diagram 8) has since beeri amply confirmed. Conversion of homogentisic acid to fumarylacetoacetic acid by a liver preparation involves uptake of the expected two atoms of oxygen (e.g., 489, 523). 

Assay of Transamination. Since the sum of keto acids and amino acids does not change in a transamination, specific reactions are required to assay the reaction products. Some of the methods used are oxidation of a-ketoglutarate to succinate and determination of succinate with succinic dehydrogenase decarboxylation of oxalacetate with aniline citrate decarboxylation with specific amino acid decarboxylases separation of products on paper chromatograms and spectrophotometric determination of those keto acids that exhibit specific absorption. 

Diethyl aniline, 54 Diethylcarbaniazine citrate, 54 Diethyl carbamyl chloride, 54 Diethyl chlorophosphate, 54 Diethylene triamine, 54 Diethyl ether, 54 Di(2-ethylhexyl) phthalate, 54 Diethyl ketone, 54 Diethyl-p-phenylenediamine, 54 Diethyl phthalate, 54 Diethylstilbestrol, 55 Diethyl sulfate, 55 Diethyl zinc, 55 Difluoromethane chloride, 55 Digitoxin, 55 Diglycidyl ether, 55 Digoxin, 55 Diisobutyl ketone, 55 Diisopropylamine, 55 Diisopropyl ether, 55 DIKAMIN , 2,4-D, 55 DIKONIRT , 2,4-D, 55 Dimefox, 55 Dimethoate, 55 3,3 -Dimethoxybenzidine, 55 n,n-Dimethylacetamide, 56 Dimethylamine, 56 4-Dimethylaminoazobenzene, 56 Dimethylaminoethanol, 56 n,n-Dimethyl aniline, 56 7,12-Dimethylbenz[a]anthracene, 56 3,3 -Dimethylbenzidine, 56... 

Fig. 2.11. Cyclic voltammograms of a poly(aniline)-coated glassy carbon electrode (deposition charge ISO mC, geometric area 0.38 cm2), recorded at 5 mV s 1 in oxygen-free 0.1 mol dm 3 citrate/phosphate buffer at pH 5 in the absence (—), and in the presence (—), of 1 mmol dm-3 NADH. Before each scan the electrode was held at -0.3 V for 3 min to ensure complete reduction of the film.

Fig. 2.12. Plot of the current as a function of time for the oxidation of 4 mmol dm- 1 NADH at 0.2 V at a poly(aniline)-coated rotating disc electrode (area 0.38 cm2, deposition charge ISO mC) in 0.1 mol dm 1 citrate/phosphate buffer, pH 5. The rotation speed of the electrode was increased in the sequence I, 4, 9, 16, 25, 36 and 49Hz and reduced in sequence back to 1 Hz. The broken line connects segments of the curve corresponding to the different rotation speeds. Note The current decays more rapidly at the higher rotation speeds and responds rapidly to changes in rotation speed.

Catalysis of NADH oxidation Figure 2.15 shows the first cycle response of two different poly(aniline)/ poly(vinylsulfonate) composite films in 0.1 mol dm-3 pH 7 citrate/phos-phate buffer with and without added NADH. 

Fig. 2.17. Plots of the current at +0.1 V for a poly(aniline)/poly(vinylsulfonate)-coated glassy carbon electrode (deposition charge 150 mC, geometric area 0.38 cm2) rotated at 9 Hz in 0.1 mol dm- 1 citrate/phosphate buffer at pH 7 as a function of the NADH concentration showing the stability of the electrode response. Four replicate calibration curves recorded in succession over 4h using the same electrode are shown ( ) run 1 ( ) run 2 (A) run 3 and (O) run 4. The solid line is drawn as a guide for the eye.

Fig. 2.19. (A) The effect of potential on the observed electrocatalytic response obtained at poly(aniline)/poly(vjnylsu fonate) electrode (geometric area 0.38 cm2, Q, 150 mC) rotated at 9 Hz in 0.1 mol dm-2 citrate/phosphate pH 7 buffer solution. Responses have been recorded at four different concentrations of NADH ( ) 0.12 mmol dm- ( ) 0.3 mmol dm"3 ( ) 0.6 mmol dm-3 and (O) 0.8 mmol dm"3. (B) Cyclic voltammetry of an identical poly(aniline)/poly(vinylsulfonate) electrode in 0.1 mol dm" 3 citrate/phosphate pH 7 buffer scanned at 5mVs , superimposed on this trace is the measured resistance for the same...

Formation of aniline blue test Upon heating insoluble oxalates with concentrated phosphoric acid and diphenylamine or upon heating together oxalic acid and diphenylamine, the dyestuff aniline blue (or diphenylamine blue) is formed. Formates, acetates, tartrates, citrates, succinates, benzoates, and salts of other organic acids do not react under these experimental conditions. In the presence of other anions which are precipitated by calcium chloride solution, e.g. tartrate, sulphate, sulphite, phosphate, and fluoride, it is best to heat the precipitate formed by calcium chloride with phosphoric acid as detailed below. 

N-(4-Piperidyl) propioanilide is prepared by the condensation of propionyl chloride with N-(4-piperidyl)-aniline. The resulting product is further condensed with phenethyl chloride to obtain the corresponding fentanyl base which on reaction with an equimolar portion of citric acid gives rise to the (1 1) citrate. 

Potassium dihydrogen citrate C6H7N Aniline a-Picoline... 

Electrodes modified by electrodeposition of poly(3-methylthiophene) [340] and poly(indole-5<arboxylic acid) films [376] show a rather nonselective catalytic effect for NADH with concomitant oxidation of, for example, dopamine, epinephrine, and acetaminophen. However, the sensitivity for NADH is increased up to 10 times and interferences such as ascorbate could be minimized by charge-selective membranes. Also, poly (aniline)-poly (vinylsulfo-nate) coated GC electrodes were shown to give stable and reproducible electrocatalytic responses to NAD(P)H in citrate-phosphate buffer at pH 7 [302]. 

---