- Synthesis and characterization of novel color chemosensors based on azo dyes for possible application in opioid pharmacology
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(Chemical Equation Presented) An applicable strategy of chemical labeling of morphine (M) and 6-acetyl morphine (6-AM) using diazonium salts is described. M or 6-AM was coupled with aryl diazoinum salts to give morphine azo dyes. The coupling of the diazotized 4,4′-diaminostilbene with M or 6-AM in ratio 1:2 gave stilbene-based azo dyes containing two M or 6-AM units, respectively. Diazotization of 5-(p-aminophenyl)-10,15,20-triphenylporphyrin and subsequent azo coupling of the diazoniun salt with M and with 6-AM was our route to get highly fluorescent morphine dyes. The resulting dyes can exist in two possible tautomeric structures, azo and hydrazone, stabilized to a significant extent by intramolecular H-bonding. It was shown that these dyes exists predominantly or exclusively in their hydrazone form. This conclusion is drawn from the lack of a distinct band in the 380-420 nm region of the absorption spectra (a region in which the long wavelength absorption band for the azo-form is observed), together with results of NMR studies in deuterated DMSO. The tautomeric properties of the compounds were judged by density functional calculations at the B3LYP/6-31G* and B3LYP/6-31G** levels. The analysis of spiked compounds in human urine samples was studied by capillary electrophoresis (CE) with UV-fluorescence photo-diode array detectors.
- Genady, Afaf R.
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- THE DIAZO REACTION OF BILIRUBIN: STRUCTURE OF THE YELLOW PRODUCTS (STUDIES ON PLANT BILE PIGMENTS-14)
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The reaction of bilirubins with aromatic diazonium salts in alcoholic solvents leads to an equimolar mixture of two types of products.One is the well-known 9-azopyrromethenone.The other is a yellow product (λmax=420nm) identified as 9-alkoxymethylpyrromethenone, the alkoxy-substituent being derived from the solvent.Thus, reaction of the symmetrically substituted bilirubins IIIα (1c) and XIIIα (1b) in methanol with diazotized sulfanilic acid yields one mole of the azopigments (4b and 4a), respectively, and one mole of the corresponding 9-methoxymethylpyrromethenones (2b and 2a).Bilirubin IXα (1a) consequently yields a mixture of all four products.The two resulting 9-methoxymethylpyrromethenones were separated by chromatography and identified as 2a and 2b.They can react further with the diazonium salts to give the corresponding 9-azopyrromethenones, but the reaction is much slower than that of bilirubin, which explains the observed product distribution.These results are discussed in relation to earlier work.
- Kufer, W.,Scheer, H.
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- Novel analogs of sulfasalazine as system xc ? antiporter inhibitors: Insights from the molecular modeling studies
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System xc ? (Sxc ?), a cystine-glutamate antiporter, is established as an interesting target for the treatment of several pathologies including epileptic seizures, glioma, neurodegenerative diseases, and multiple sclerosis. Erastin, sorafenib, and sulfasalazine (SSZ) are a few of the established inhibitors of Sxc ?. However, its pharmacological inhibition with novel and potent agents is still very much required due to potential issues, for example, potency, bioavailability, and blood–brain barrier (BBB) permeability, with the current lead molecules such as SSZ. Therefore, in this study, we report the synthesis and structure–activity relationships (SAR) of SSZ derivatives along with molecular docking and dynamics simulations using the developed homology model of xCT chain of Sxc ? antiporter. The generated homology model attempted to address the limitations of previously reported comparative protein models, thereby increasing the confidence in the computational modeling studies. The main objective of the present study was to derive a suitable lead structure from SSZ eliminating its potential issues for the treatment of glioblastoma multiforme (GBM), a deadly and malignant grade IV astrocytoma. The designed compounds with favorable Sxc ? inhibitory activity following in vitro Sxc ? inhibition studies, showed moderately potent cytotoxicity in patient-derived human glioblastoma cells, thereby generating potential interest in these compounds. The xCT-ligand model can be further optimized in search of potent lead molecules for novel drug discovery and development studies.
- Patel, Dhavalkumar,Kharkar, Prashant S.,Gandhi, Neha S.,Kaur, Ekjot,Dutt, Shilpee,Nandave, Mukesh
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p. 758 - 777
(2019/06/24)
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- Sustainable Synthesis of Balsalazide and Sulfasalazine Based on Diazotization with Low Concentrations of Nitrogen Dioxide in Air
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Low concentrations of nitrogen dioxide, which arises as a side product from a range of industrial processes, can effectively be recycled through the diazotization of anilines. The studies reported herein now demonstrate that the removal of nitrogen dioxide from gas streams is even more effective when hydrophilic anilines are used as starting materials. The diazonium salts, which are obtained in this way in up to quantitative yields, can directly be employed in azo coupling reactions, thus opening up an attractive route to the industrially important group of azo compounds.
- Hofmann, Dagmar,Gans, Eva,Krüll, Jasmin,Heinrich, Markus R.
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supporting information
p. 4042 - 4045
(2017/03/31)
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- Synthesis and anti-oxidant evaluation of some novel sulfa drugs
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Background: Curcumins were reported to possess anti-inflammatory and antiangiogenic. Furthermore, Curcumin is a very potent free radical scavenger than vitamin E. Moreover, cyanoacetamides were reported to possess, antimicrobial antifungal, insulin releasing, antiinflammatory and antitumor. Thus the present study focuses on the synthesis of some novel structure hybrids incorporating either curcumin or cyanoacetamide with sulphonamide, aiming to reach a more potent antioxidant agent. Methods: 4-arylazoenol derivatives 12-16 and E-hydrazo derivatives 19-23 were prepared and their structure was confirmed by variable spectra analysis. The newly synthesized compounds were screened for their antioxidant activity using ABTS and Bleomycin-dependent DNA damage methods. Results: Coupling of the diazonium salts 7-11 of different sulpha drugs with curcumin 1 or with cyanoacetamide 18 afforded the corresponding 4-arylazoenol derivatives 12-16 and E-hydrazo derivatives 19-23. Among all the synthesized compounds, 12-16, 18, 20 and 22 were the most potent antioxidant compounds. Conclusion: The objective of the present study was to synthesize and evaluate the antioxidant activity of some novel sulfonamides structure hybrids incorporating either curcumin or N-[4- (aminosulfonyl) phenyl]-2-cyanoacetamide moiety with the hope of discovering new structure serving as antioxidant agent. The data showed clearly that most of compounds displayed good in vitro antioxidant activities.
- Gouda, Moustafa A.,Hussein, Belal H.M.
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p. 1425 - 1432
(2017/12/28)
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- Graphene quantum dot grafting azo derivative composite material, and preparation method and application of same
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The invention discloses a graphene quantum dot grafting azo derivative composite material, and a preparation method and an application of same. The preparation method comprises the steps of: 1) dispersing graphene quantum dots (GQDs) in thionyl chloride and N,N-dimethylformamide (DMF) and performing a reflux reaction to obtain an acylchloridized graphene quantum dot material (GQDs-COCl); 2) performing a reaction to sulfanilic acid azo-phenol (SUL-Ph) with the GQDs-COCl in tetrahydrofuran to produce the graphene quantum dot grafting azo derivative composite material. The graphene quantum dot grafting azo derivative composite material has strong recognizing capability, high selectivity and good stability on metal ions in molecular fluorescence, so that the material may be applied to the fields such as biomedicines, sensors, optical and electronic devices, solar cells, electronic equipment, optical fuels, composite particle systems, etc.
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(2018/03/24)
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- Determination of labetalol hydrochloride in drug formulations by spectrophotometry
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A validated, selective and sensitive spectrophotometric method has been developed for the determination of labetalol hydrochloride in commercial dosage forms. The method is based on the coupling reaction of positive diazonium ion of 4-aminobenzenesulfonic acid with phenolate ion of labetalol to form a colored azo compound which absorbs maximally at 395 nm. Under the optimized experimental conditions, the color is stable up to 2 h and Beer's law is obeyed in the concentration range of 0.8-17.6 μg mL-1 with a linear regression equation of A = 4.84 × 10-4 + 7.864 × 10-2 C and coefficient of correlation, r = 0.9999. The molar absorptivity and Sandell's sensitivity are found to be 2.874 × 104 L mol-1 cm-1 and 0.013 μg cm-2 per 0.001-absorbance unit, respectively. The limits of detection and quantitation of the proposed method are 0.08 and 0.23 μg mL-1, respectively. The intra-day and inter-day precision variation and accuracy of the proposed method is acceptable with low values of standard analytical error. The recovery results obtained by the proposed method in drug formulations are acceptable with mean percent recovery ± RSD of 99.97 ± 0.52 - 100.03 ± 0.63%. The results of the proposed method compared with those of Bilal's spectrophotometric method indicated excellent agreement with acceptable true bias of all samples within ± 2.0%.
- Rahman, Nafisur,Rahman, Habibur,Azmi, Syed Najmul Hejaz
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p. 185 - 196
(2008/02/09)
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- Diazo dyestuff compounds and their use
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The present invention relates to a diazo dyestuff compound of the following formula (I) wherein, M is H, Na, or Li. The formula (I) compound is particularly suitable for using as a component in a black dye composition for ink-jet printing ink, and inkjet printing inks with good light-fastness are obtained.
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(2008/06/13)
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- 4,4'-DIAZOBENZANILIDE DYESTUFFS
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The present invention provides 4,4'-diazobenzanilide derivatives, a process for their preparation, their use as dyes, dyed paper, formulations comprising them and also precursors thereof and their processes of preparation.
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Page/Page column 30
(2008/06/13)
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- Process for producing 7-amino-6-demethyl-6-deoxytetracycline
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This invention provides a new process for producing 7-amino-6-demethyl-6-deoxytetracycline (Compound 3) which is an intermediate for the synthesis of minocycline. Compound 3 can be obtained by reduction of Compound 1 using a dithionite as reducing agent. This invention also provides a method to produce Compound 3 from Compound 2 in one pot. STR1 (wherein Ar denotes a substituted aryl group, and X stands for the residue of a mineral acid from which hydrogen atom has been eliminated).
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- The Influence of Chlorine and Sulphonate Substituents on the Visible Absorption Maxima of Some Azo Dyes
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A total of 110 arylazo dyes have been prepared, based on five benzenoid and heterocyclic coupling components, and containing combinations of chlorine and sulphonate (sulpho) substituents in the diazo components.Their visible absorption maxima have been analysed in order to determine the degree to which chloro and sulfo substituent influences are constant and transferable, both within a series, and between series.Additivity is found to pertain, if allowances are made for steric effects.A 2-sulpho group alone can induce nonplanarity, depending on the nature of the coupling component.The 2-sulpho-3-chloro combination is particularly responsible for hypsochromic shifts unexpected on the basis of strict additivity.Computer-aided molecular modelling studies have clarified the steric interactions present.Di-ortho-substitution also induces nonplanarity and hypsochromic effects.There is some evidence for non-equivalence of a substituent in the two distinct meta-orientations, although MO calculations do not reproduce this behaviour.
- Greenwood, David,Hutchings, Michael G.,Lamble, Brian
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p. 1107 - 1114
(2007/10/02)
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- USE OF CURRENTLESS POTENTIAL-TIME CURVES FOR DETERMINING THE RATE CONSTANTS OF DIAZOTATION REACTIONS
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The kinetics and the rate constants for the diazotation of nine aromatic amines at various conditions (temperature, medium) were determined by the method of currentless potential-time curves.A comparison with an independent method and with literature data is presented.
- Dlask, Vladimir
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p. 2315 - 2319
(2007/10/02)
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- STUDIEN ZUM VORGANG DER WASSERSTOFFUEBERTRAGUNG 62. HERSTELLUNG UND ELEKTROREDUKTIVE SPALTUNG EINIGER ARYLDISULFONSAEUREDERIVATE
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Benzene-disulfonylchlorides were converted to the corresponding dialkyl- and diphenylesters, N-alkyl- and N-aryl disulfonamides.The half-wave-potentials E11/2 and E21/2 were measured and the products obtained on potentiostatic fission at E11/2 were isolated and characterized.The electroreduction of benzene-1,4-disulfonic acid-diphenylester in methanol yields phenol in quantity approximately corresponding to the current passed, but no corresponding quantity of sulfinic acid.In dry acetonitrile, benzene-1,4-disulfonic acid diesters and diamides undergo potentiostatic fission (at E11/2) in good chemical and current yields, giving the corresponding monosulfonate-sulfinic acid or monosulfonamide-sulfinic acid and alcohol or amine.The passage of further electrical current reduces the sulfinic acids to other, as yet undetermined, products.
- Horner, Leopold,Schmitt, Rolf-Elhard
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p. 169 - 178
(2007/10/02)
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