Carbazole Reaction Research Articles

Organoamido- and Aryloxo-Lanthanoids. I. The Preparation and Characterization of Some Lanthanoid(II) Organoamides, and the X-Ray Crystal Structure of cis-Bis(Carbazol-9-Yl)Tetrakis(tetrahydrofuran)europium(II)

Reaction of carbazole ( Hcbz ) or 2-phenylindole ( Hpin ) with bis ( pentafluorophenyl )-ytterbium or -europium in tetrahydrofuran ( thf ) gives the complexes M( cbz )2( thf )4 (M = Yb or Eu ) or Yb (pin)2( thf )4. From treatment of lanthanoid metals with bis ( pentafluorophenyl )mercury and 2-phenylindole, 2,3,4,5-tetraphenylpyrrole ( Htpp ) or carbazole , the complexes M(pin)2( thf )4 (M = Yb , Eu or Sm ), M( tpp )2( thf )3 (M = Yb or Sm ) and Yb ( cbz )2( thf )4 have been isolated. Desolvation of M(pin)2( thf )4 under vacuum yields Yb (pin)2( thf ) and Sm (pin)2( thf )3. Oxidation of Sm (pin)2( thf )4 with Hg(C6F5)2 and 2-phenylindole gives Sm (pin)3( thf ). The crystal structure of Eu ( cbz )2( thf )4 shows the complex to be monomeric with distorted octahedral stereochemistry for europium, cis-carbazol-9-yl ligands ({ Eu -N} 2.559 Ǻ), and longer Eu -O bonds (av. 2.600Ǻ) trans to N than mutually trans ({ Eu -O} 2.553Ǻ). Other complexes M(NR2)2( thf )n (NR2 = pin, cbz or tpp ) are considered to be monomeric with five (n = 3) or six (n = 4) coordination.

Excited state deprotonation reactions of aromatic amines: a diffusion-controlled process

The excited state proton transfer reactions of carbazole (CAZL), indole (IND) and diphenylamine (DPA) were studied using a picosecond time-resolved technique. The forward rate constant for deprotonation shows a slight temperature dependence. The activation energy for the process was determined by taking various bases in both aqueous and non-aqueous media. It is of the order of the diffusional barrier in the solution phase. Hence it is concluded that the process is diffusion controlled. The values of the diffusion-controlled rate constants are discussed.

Mutagenicity of the reaction products of carbazole in the presence of nitrogen dioxide and nitrocarbazole

The mutagenicity of the photochemical reaction products of carbazole in the presence of nitrogen dioxide (NO 2) and nitrocarbazole was investigated using a high-pressure mercury lamp (100 W). Samples extracted from the photochemical reaction products of carbazole with NO 2 were more mutagenic than those of acridine and phenazine with NO 2 for Salmonella typhimurium strain TA98 in the absence of S9 mix with a trend toward detoxification in the presence of the metabolic system. The mutagenicity of the photochemical reaction products of carbazole with NO 2 were higher than those of the products of carbazole with a mixture of NO 2 and sulfur dioxide (SO 2) and no irradiation. Mononitro- and dinitro-carbazole in the samples extracted from the reaction products were analyzed by mass spectrometry. It was suggested that mononitrocarbazole, which seemed to be weakly mutagenic, and dinitrocarbazole were readily formed by the reaction of carbazole with NO 2, and that the other high-potency mutagens were formed by the photo-chemical reaction of carbazole with NO 2 with irradiation by light.

ChemInform Abstract: Reactions of Electron‐Rich Heterocycles with Orthocarboxylic Acid Derivatives. Part 11. Reactions of Carbazole and 4‐Methoxycarbazole with Triethyl Orthoformate: Regiospecific Functionalization of the Carbazole Nucleus.

AbstractCarbazole (I) reacts with triethyl orthoformate (II) to yield the N‐formyl derivative (IV) after hydrolysis.

両側臼歯欠損が顎関節滑液のグリコサミノグリカンに及ぼす影響についての生化学的研究

This study was designed to determine the effect of bilateral extraction of all molars and premolars on glycosaminoglycans (GAG) in the synovial fluid of the monkey temporomandibular joint (TMJ). TMJ radiographs were taken using standard techniques at intervals of 2, 4, 8, 16, and 24 weeks following surgery. The synovial fluid was digested with pronase E and GAG were extracted using CPC at intervals of 2, 8, 16, and 24 weeks following surgery. Qualitative and quantitative changes in the GAG were examined by the carbazole reaction and electrophoresis on a cellulose acetate strip. The molecular weight distribution of GAG was examined by gel chromatography.The following results were obtained1) No morphological changes were observed in the condylar head or articular eminence, although the position of the condyle changed in a superoposterior direction in the 16 and 24 week groups.2) The GAG was composed of hyaluronic acid (HA) only.3) HA concentration as uronic acid was initially 2. 13 mg/m/, gradually decreasing with time.4) Gel chromatogrophy-measured HA in the experimental groups was eluated later than the control group, indicating a decrease in the molecular size of HA in the experimental groups. Decreased molecular size of HA was observed up until the 16 week; an increase to the 2 week level was observed in the 24 week group.It is suggested that bilateral extraction of molars in monkeys caused quantitative and qualitative changes in the HA of the synovial fluid.

Reactions of electron‐rich heterocycles with orthocarboxylic acid derivatives. 11. Reactions of carbazole and 4‐methoxycarbazole with triethyl orthoformate: Regiospecific functionalization of the carbazole nucleus

AbstractCarbazole (1a) and 4‐methoxycarbazole (1b) can be regioselectively functionalized by reaction with triethyl orthoformate. Whereas the reaction of 1a with the ortho ester furnishes the amide acetal 2, the new carbazole derivatives 4–10 are formed, depending on the reaction conditions, in the electrophilic substitution of 1b. The products of this reaction sequence provide a contribution to studies on the mechanism of the transformation of 1b to tris‐carbazolylmethane 5. Compound 5 represents a new, three‐bladed propeller in the triheteroarylmethane series.

Screening for mucopolysaccharide disorders with the berry spot test

The Berry spot test, based on metachromatic straining of urinary acid mucopolysaccharides (MPS), is widely used to screen for inherited MPS disorders. During a 5-year period over 6000 specimens from a variety of patients were tested as part of routine metabolic screening. Urine was applied to filter paper, stained with toluidine blue, and destained by washing in acetic acid. Over 90% of specimens showed no metachromasia. Quantitative measurements of hexuronic acid were carried out on all specimens with positive tests using the borate modification of the Dische carbazole reaction. Molecular species were identified following electrophoresis on cellulose acetate and staining with alcian blue. Mean concentration of hexuronic acid in specimens with + reaction was 113 +/- 67 mumol/L. Only chondroitin sulfate A/C was identified by electrophoresis. Hexuronic acid concentration in strongly positive + + + specimens ranged from 335-1546 mumol/L, and heparan sulfate, dermatan sulfate or both were identified. Additional specimens were obtained from patients with + + + reactions and from 15 control children with negative spot tests. Excretion of hexuronic acid by + + + patients was 175-258 mumol/day (84-181 mmol/mol creatinine) compared to 41 +/- 36 mumol/day (10 +/- 5 mmol/mol creatinine) by control subjects. Urine testing simplifies the differential diagnosis by demonstrating the biochemical defect and pointing to the probable enzyme defect. The screening test has been highly effective in identifying patients with MPS disorders.

Equilibrium p K* of carbazole studied by the deprotonation reaction in ammoniacal aqueous media

Forward and backward rate constants for the excited state deprotonation reaction of carbazole in ammoniacal aqueous media were determined from both steady state (Weller's fluorescence quenching technique) and direct kinetic studies. The results establish that the equilibrium p K * may be significantly different from the “apparent” p K * obtained by the fluorometric titration method.

Re-examination of the products of the action of galactose oxidase. Evidence for the conversion of raffinose to 6''-carboxyraffinose.

Galactose oxidase is a fungal enzyme which is known to oxidize the C-6 hydroxymethyl of galactose to an aldehyde group. When the products of a galactose oxidase-catalase treatment of raffinose were examined by gel filtration and ion exchange chromatography, we found that, in addition to the expected 6''-aldehydoraffinose, two other components were present. Of these two components, the major one was retained on a column of AG 1-X8 (formate), gave a positive carbazole reaction for uronic acid, and on paper chromatograms had a mobility identical with that of 6''-carboxyraffinose. The infrared spectrum of the compound showed a carbonyl absorbance at 1725 cm-1 and was distinguishable from the spectra of raffinose and 6''-aldehydoraffinose. These data showed that raffinose was partly converted to 6''-carboxyraffinose when treated with galactose oxidase and catalase. The conversion of [3H]raffinose to [3H]6''-carboxyraffinose increased gradually with time of oxidation from 22% at 6 h to 68% at 96 h. Results of other experiments provided evidence that this was an enzymic conversion and depended on the presence of galactose oxidase. The activities responsible for the formation of aldehyde and uronic acid could not be separated by affinity chromatography, gel electrophoresis, or ion exchange chromatography, indicating that the same enzyme is responsible for both activities. Treatment of galactose, melibiose, and stachyose with galactose oxidase and catalase also resulted in the formation of the corresponding uronic acids. These studies indicate that galactose oxidase not only converts the C-6 hydroxymethyl group of galactose to an aldehyde group, but also catalyzes further oxidation to the carboxyl group.

Continuous-flow monitoring of hexuronic acid by carbazole reaction during gel filtration of proteoglycans in urea solutions

Continuous-flow monitoring of hexuronic acid by carbazole reaction during gel filtration of proteoglycans in urea solutions

Excited-state proton transfer kinetics of carbazole

Rate constants for the excited-state proton transfer reaction of carbazole in aqueous alkaline solution have been determined using picosecond single photon counting. Fluorescence decay measurements show that the back reaction is slow compared to the fluorescence decay time and therefore equilibrium is not attained in the excited state. The validity of a pK value for the lowest excited state determined from steady-state fluorescence measurements assuming equilibrium is discussed. It is concluded that the thermodynamic pK * value for carbazole is 10.98.

Relative molecular weight and concentration determination of sodium hyaluronate solutions by gel-exclusion high-performance liquid chromatography

Gel-exclusion chromatography coupled with HPLC instrumentation can be used to determine the molecular weight of highly purified sodium hyaluronate in solution. The method is very reproducible, precise, and rapid, and allows molecular weight determinations up to 2 million to be done in the presence of considerable impurities. This technique offers considerable advantages over traditional light-scattering, sedimentation equilibrium, and viscometry methods for molecular weight determinations, in that HPLC-gel exclusion is rapid and not subject to errors arising from impurities. Simultaneous with molecular weight measurements, sodium hyaluronate concentrations can be determined with a lower range of 0.1 to 0.3 mg/ml dependent upon the sensitivity of the refractive index-detecting system. Unlike the carbazole reaction, this technique is unaffected by low-molecular-weight impurities such as monosaccharides or substances with relative molecular weights less than 18,000.

A convenient method for obtaining 3-chloro- and 3,6-dichlorocarbazoles

It has been shown that the reaction of carbazole and some of its derivatives with phosphorus pentachloride in 1,2-dichloroethane leads predominantly to 3-chloro- and 3,6-dichlorocarbazoles, depending on the reaction conditions.

Photochemical reaction of carbazole and some derivatives in dichloromethane

By irradiation of carbazole and some derivatives in CH 2Cl 2 soln two different reaction pathways were observed depending on the substitution of the heterocyclic compound.

Use of holography to investigate photochemical reactions from higher excited states. Action spectrum of the second-photon step in the two-photon dissociation reaction of carbazole

Use of holography to investigate photochemical reactions from higher excited states. Action spectrum of the second-photon step in the two-photon dissociation reaction of carbazole

Dietary Fiber Content of Corn Bran

The dietary fiber (DF) content in a corn bran flour obtained from Tabor Milling Company was estimated and analyzed using a fractionation procedure developed previously. This method includes estimation of cold and hot water-soluble biopolymers as well as total pectic substances, hemicellulose, cellulose and Klason lignin. Quantitative and qualitative analysis of the neutral sugars in the carbohydrate polymers was achieved by gas-liquid chromatography. Acidic sugars were estimated by a modified carbazole reaction. The corn bran flour was estimated to contain 50.12% total DF. The DF was composed of 34.49% hemicellulose, 12.34% cellulose, 0.23% Klason lignin and 3.06% total pectic substances. These values were similar to those obtained from the analysis of a standard wheat bran using the same methodology in another study.

Study on the factors yielding high color in the carbazole reaction with hexuronic acid-containing substances.

The color yields with hexuronic acids and hexuronic acid-containing substances were studied by means of the carbazole method of Bitter and Muir with or without 0.025 M borate. The carbazole-borate to carbazole (CB/C) ratios thus obtained indicated not only the degree of the borate effects on the color yields with these materials but also the anomalous nature of some of these substances in the carbozole reaction. The present data indicate that the high color yield with heparin in the carbozole reaction may be due to the production of free amino groups from acid-labile sulfamino groups in the early stage of the reaction, resulting in suppression of protonation on the alpha-D-glucosaminidic oxygen atoms attached to the hexuronic acid residues in the molecule. Moreover, it is suggested that the degree of the unusual color yields in the carbazole reaction with glycosaminoglycans is greatly influenced by the anomeric configuration of the hexosaminyl linkages attached to the hexuronic acid residues in these polymers.

Normal isotope effect on the rate of dissociation of carbazole in the excited state

The kinetics of the dissociation reaction of carbazole in the excited state has been investigated by measuring the fluorescence lifetime in the dilute alkaline H 2O and D 2O solutions. A normal isotope effect has been observed on the dissociation reaction rate, but the difference of the activation energies is less than the difference of the zero-point vibrational energies between NH and ND bonds.

Determination of Chondroitin‐4‐Sulfate through Its Uronic Acid Content

AbstractA standardized new variant of the uronic acid determination based on carbazole reaction is suggested which has been proved for routine analyses. Its relative error is less than ± 2% in case of measuring 50–340 μg chondroitin‐4‐sulfate or the equivalent glucuronic acid. The method is suitable for determining other mucopolysaccharides, polyuronides and uronic acids, too.

Influence of glycosaminoglycan content on mass transfer behavior of porcine artery wall Part 2. Differences in mass transfer rates related to variations in glycosaminoglycan content

It has been suggested that the glycosaminoglycans (GAG) influence atherogenesis by regulating the permeability of the arterial wall. For this reason, a study has been made of the diffusive transport of Ca 2+ and water across the in vitro porcine artery wall, where particular attention was focused on the influence of GAG content and distribution within the wall on the transport properties. The radioisotopes 45Ca and 3HHO were used to measure the tracer-diffusion flux in a stirred, two chamber diffusion cell. GAG were isolated, fractionated using a cetyl pyridinium chloride-cellulose column procedure, and assayed using a colorimetric carbazole reaction for uronic acid. The biochemical analyses showed that the pulmonary artery contains significantly more hyaluronic acid and dermatan sulfate than found in two locations in the thoracic aorta. In addition, a significant regression was found for the diffusion coefficient of 45Ca 2+ (99% level) and 3HHO (95% level) versus specific GAG fractions. The regression indicated an increase in permeability with increase in the ratio of sulfated : nonsulfated GAG.