Benzidine Reaction Research Articles

Synthesis, Characterization, and Evaluation of Antioxidant and Physical Properties of New Bifunctional Aromatic Monomers Containing Imine and Heterocyclic Rings in The Main Chain.

New various monomers with di amine functional groups have been synthesized, containing di azomethine or di seven-membered heterocyclic rings in the backbone. A condensation reaction of benzidine with 4-amino benzaldehyde with some drops of glacial acetic acid in ethanol absolute prepared bi-functional amino groups monomer with azomethine core P1(4-[(1E)-[4[4-(E)-(4-aminophenyl)methylidene]amino]phenyl}phenylimino methyl aniline). The next step was the Cycloaddition reaction of P1 with succinic, malic, and phthalic anhydrides used to obtain aromatic heterocyclic monomers with oxazepane and oxazepine rings containing lactone and lactam groups. All the synthesized monomers were characterized spectrally with many techniques (FT.IR,1 H1.NMR, C13-NMR) that were used to investigate the functional groups in the structure of monomers. Monitoring the progress and completion of the reaction was performed using thin-layer chromatography (TLC). Physical characterizations, including detecting the melting point, purity, colour, retardation factor, molecular formula, and molecular weight, the polarized optical microscope (POM) used for Image-based microscopic interpretation of prepared compounds. All the prepared monomers are considered effective antioxidant agents as they give free radicals scavenging over 60%, reaching 80 %; this activity makes them useful in large numbers of industries as they can scavenge the free radicals that the industrial product may be exposed, which increases its shelf life and enhance its effectiveness.

VETERINARY AND SANITARY ASSESSMENT OF THE MEAT FROM ANIMALS AFTER ORAL ADMINISTRATION OF THE ANTIPARASITIC DRUG «DEGELM-16»

The paper presents veterinary and sanitary assessment of the meat from rabbits and pigs, who had taken a new anthelmintic drug «Degelm-16» in their diet. The meat from 6 rabbits and 6 gilts who were divided into experimental and control groups was studied, three samples per each group. The drug «Degelm-16» was given alimentary with foodstuff to the animals of the experimental group 5 days before the slaughter at a dose of 50 mg/kg. Rabbits and gilts of the control group did not receive the drug. It was discovered that meat samples taken in the control and experimental groups of rabbits and gilts contained a drying crust, elastic muscle fibers. The characteristic smell of test samples corresponded to the specimens species. Meat samples from both animal species were of pale pink colour. Boiling of the meat from rabbits and gilts resulted in cloudy-white broth with pleasant specific smell. The benzidine reaction revealed a peroxidase positive result in the meat extract. The amount of amino-ammonia nitrogen in both rabbit groups ranged from 0.54 to 0.60 mg, in gilt groups – from 0.76 to 0.79. The volume of volatile fatty acids in rabbit meat samples ranged from 1.82 to 1.89 mg KOH. In gilt meat – from 2.19 to 2.43 mg KOH of volatile fatty acids. The reaction for the protein primary decomposition products using copper sulphate in both groups resulted in getting the broth without clots and flakes confirming appropriateness of the meat. The touch smears bacterioscopy showed presence of single microorganisms in the surface layers and complete absence of the bacteria in the deep layers. The data of microbiological analysis did not reveal deviations from the reference values.

Synthesis, Characterization and Preliminary Antimicrobial Evaluation of New Schiff bases and Aminothiadiazole Derivatives of N- Substituted Phthalimide

A new series of schiff base and aminothiadiazole derivatives of N- substituted phthalimide (I-VI) were synthesized. In this work, the intermediate 4-(1,3-dioxoisoindolin-2-yl)benzaldehyde compound (I), was formed by reaction of 4-amino benzaldehyde with phthalic anhydride in glacial acetic acid(GAA). A series of Schiff bases (IV-VI) was prepared by the reaction of benzidine with compound (I) in ethanol and presence of GAA as a catalyst to form compound (IV) which react with compound (I) and p-nitro benzyldehyde to give compound (V) and (VI) respectively. A new phthalimide thiosemi-carbazone derivative (ll) was prepared by reaction of compound (l) with thiosemi-carbazide HCl in the presence of equimolar amount of sodium acetate. Finally, a new phthalimide containing (1,3,4- thiadiazole ring) compound (III) was formed by bromine mediated “oxidative intramolecular cyclization” of compound (I) in the presence of sodium acetate. All of the final target compounds' structures were successfully synthesized and confirmed using analytical and spectroscopic data. These compounds were identified and confirmed by melting points, TLC, FT IR, and 1H NMR. While the antimicrobial effect of the new derivatives has been assessed in vitro against G-positive, G-negative bacteria and fungi activity. All screened compounds exhibited no activity against G-positive bacteria (Staph. Aureus, and Bacillus subtilis). Many of synthesized compounds displayed moderate effect against “G-negative bacteria Escherichia coli, and Klebsiella pneumonia and against Candida tropicalis”. While the best antifungal activity was obtained from compound I which has high activity against Candida tropicalis.

Synthesis, Characterization and Anticancer Evaluation of Some New Heteroatom Compounds

This work deals with the preparation of high yield compounds by simple methods through two parts: the first part involves the preparation of compounds RU1 and RU3 by the reaction of melamine with chloroacetic acid in existence of sodium acetate. The second part includes the preparation of compounds RU2 and RU4 by the reaction of benzidine with chloroacetic acid. The reactions were followed by TLC and the prepared compounds were characterized by FT-IR, 1H-NMR and 13C-NMR techniques. The prepared compounds show a good biological activity against MCF-7.

Synthesis and Characterization of Cr(III) & Fe(II) Bis(2-Methoxybenzylidene)Biphenyl-4,4'-Diamine Complexes

Bis(2-methoxybenzylidene)biphenyl-4,4'-diamine Schiff base was prepared by the reaction of benzidine and O-methoxy benzaldehyde 1:2 reaction. Two complexes of this ligand with Cr(III) and Fe(II) were prepared. All prepared compounds were analysed using elemental analysis, IR, 1H NMR and mass spectroscopy. The formation of proposed structures, including the free ligand and complexes were confirmed.

A novel sensitive and fast colorimetric assay for determination of benzidine as a carcinogen aromatic amine based on Bromopyrogallol red

ABSTRACTBenzidine and its derivatives are among human or animal carcinogens. Therefore, there is an ever-increasing demand for methods suitable for their determination. Herein, we have reported a naked-eye detection method which is based on the benzidine (among carcinogen) reaction with a chromogenic indicator (Bromopyrogallol red (BPR)). The dye-based ensemble systems are expected to be a potential and practical way for the detection of nanomolar concentrations of benzidine in 75% water media. The absorbance signal of BPR increases linearly in the concentration range of 3.25 × 10−7–3.34 × 10−5 mol L−1 for benzidine. The chemosensor enabled sensitive and selective detection of benzidine with a detection limit of 4.17 × 10−8 mol L−1. The RSD value (n = 6) of 9.7 × 10−7 and 3.7 × 10−6 mol L−1 benzidine was determined to be respectively 2.3% and 2.1%. This process proceeded with distinct visual color change within 1.0 min in aqueous solution. We tested the actual samples successfully, and the measurement results were compared with the gravimetric technique for benzidine. It showed that our method exist no significant difference with standard methods by the Student t-test. Therefore, we provided a rapid, simple, sensitive, accurate, and reliable new method for the determination of benzidine in real samples. Advantages offered by the proposed method, compared with those suggested previously of benzidine determination indicates that they have the second detection limit. This system is simple in design, fast in operation and is more promising than previous methods. This approach eliminated the need for the separation stages, multiple-step reactions, sample preparation, chemical modifications, and sophisticated instrumentations.

Synthesis and Identification of Heterocyclic Compounds (Oxazepine, Tetrazole) Derived from Benzidine as Photostabilizing for Poly vinyl chloride

This research describes preparation of new four compounds (A2-A5) having 1,3-oxazepine and Tetrazole rings. The first step involves reaction of benzidine (A1) with aromatic aldehyde (cinnamaldehyde) in ethanol as a solvent in the presence of acid as catalyst to yield the Schiff base (A2), Schiff base (A2) was condensed with maleic anhydride and phthalic anhydride in dry benzene to give a seven-membered heterocyclic ring derivative (A3, A4), In addition, we synthesis novel tetrazole derivative (A5) from the reaction of Schiff base (A2) with sodium azide in tetrahydrofuran. The structure of synthesized compounds were identified by spectral methods [FTIR, ¹H-NMR, and ¹³C-NMR] and measurement physical properties. The photo stabilization of poly (vinyl chloride) films by compounds (A1-A5) was studied. The Photostabilization activities of these compounds were determined by monitoring the carbonyl and hydroxyl indexes values with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were studied by using tetrahydrofuran as a solvent. The influence of concentrations additives (range 0.1-0.5wt) on the rate of photodegradation and Photostabilization course was studied. Therefore, we found that was an increase Photostabilization rates with increasing concentrations of additives. In addition, Studying the effect of film thickness and the results showed that an increase in film thickness would reduce the rate of photolysis. The results indicated that Photostabilisation proportion of plastic in the presence of additives follow the trend: (PVC blank) > PVC+A1> PVC+A2 > PVC+A5> PVC+A4> PVC+A3. According to the results obtained, it proposed mechanisms depending on the structure of the additive.

Bis-2(5H)-furanone derivatives as new anticancer agents: Design, synthesis, biological evaluation, and mechanism studies.

New bis-2(5H)-furanone derivatives containing a benzidine core were synthesized via a one-step transition-metal-free reaction of benzidine with 5-substituted 3,4-dihalo-2(5H)-furanones. Their antitumor activities against various tumor cells have been evaluated by MTT assay. Among them, compound 4e exhibits significant inhibitory activity against C6 glioma cells with an IC50 value of 12.1μm and low toxicity toward HaCaT human normal cells. Studies on the antitumor mechanism reveal that cell cycle arrest at S-phase in C6 cells is induced by compound 4e. Furthermore, investigations with electronic, fluorescence emission and circular dichroism spectra show that compound 4e can significantly interact with C6-DNA. These data indicate that DNA may be one of the potential targets for bis-2(5H)-furanone derivatives as anticancer drugs.

Indirect colorimetric detection of glutathione based on its radical restoration ability using carbon nanodots as nanozymes

This work addresses a colorimetric sensor for glutathione (GSH). In this study carbon nanodots (CDs) were used as the peroxidase mimetic catalysts. The blue colored free cation radicals were generated simply by an oxidation reaction of tetramethyl benzidine (TMB) which was catalyzed by CDs as the catalysts. So, the key role of the CDs was the enhancement in radical generation thereby enhancing the system sensitivity. The results in this study showed that the free radical cation concentration was inversely related to the GSH concentration in the range of 0–7μM with a detection limit of 0.3μM. Moreover, this system showed a perfect selectivity over non-thiolated biological molecules. As a practical application, this chemosensor was used to measure the GSH content of the whole human blood with the results consistent with that of a classical Ellman method.

Localization of sulfated sialic acids in the dentinal tubules during tooth formation in mice

Lectin-like properties of the major enamel protein amelogenin suggest that it binds to glycoconjugates in dentinal tubules released at the dentin-enamel junction (DEJ) during enamel formation. Therefore, a detailed mapping of glycosylation in dentinal tubules during tooth formation was undertaken using histochemistry and lectin-binding assays. The tubular content exhibited sialidase-susceptible gamma-metachromasia with Toluidine Blue (pH 2.5) and staining with Alcian Blue (pH 1.0). The presence of sulfate groups was confirmed by benzidine reactions (Bracco-Curti's and tetrazonium assays). Alpha2,3-, alpha2,6- and alpha2,8-sialidases entirely abolished staining with the benzidine reactions. The presence of sialic acids in dentinal tubules was confirmed with the Bial's reaction and sialidase-susceptible binding of Limax flavus lectin suggesting that sialic acids are the major sulfated sugars in the glycoconjguates. Immunostaining with the monoclonal antibody 5-D-4 before and after treatment with chondroitin-4- and chondroitin-6-sulfatase confirmed the presence of keratan sulfate (KS), a sialylated proteoglycan, in dentinal tubules. We suggest that sulfated sialic acids are part of the KSs. The sulfated glycoconjugates are also found in dentin and the DEJ but not in predentin suggesting that amelogenin binds to the sialoconjugate during enamel formation.

Activation of the MEK5/ERK5 Cascade Is Responsible for Biliary Dysgenesis in a Rat Model of Caroli's Disease

Polycystic kidney (PCK) rats exhibit a multiorgan cyst pathology similar to human autosomal recessive polycystic kidney disease, and are proposed as an animal model of Caroli's disease with congenital hepatic fibrosis (CHF). This study investigated the expression and function of selected components of the mitogen activated protein kinase (MAPK) pathway in cultured intrahepatic biliary epithelial cells (BECs) of PCK rats. Compared to the proliferative activity of cultured BECs of control rats, those of the PCK rats were hyperresponsive to epidermal growth factor (EGF). The increase in BEC proliferation was accompanied by overexpression of MAPK/extracellular signal-regulated protein kinase (ERK) kinase 5 (MEK5), and subsequent phosphorylation of ERK5 in vitro. The increased proliferative activity was significantly inhibited by the transfection of short interfering RNA against MEK5 mRNA. An EGF receptor tyrosine kinase inhibitor, gefitinib ("Iressa", ZD1839), also significantly inhibited the abnormal growth of cultured BECs of PCK rats. By contrast, treatment with PD98059 and U0126, inhibitors for MEK1/2, was less effective. These results suggest that the activation of the MEK5-ERK5 cascade plays a pivotal role in the biliary dysgenesis of PCK rats, and also provide insights into the pathogenesis of Caroli's disease with CHF. As the MEK5-ERK5 interaction is highly specific, it may represent a potential target of therapy.

Appearance of erythrocyte-like globules in the mouse visceral yolk sac endodermal cells on embryonic day 12, with special reference to blood islands

The mouse visceral yolk sac (VYS) is widely known to play an important role as erythropoietic tissue during embryonic periods. Mouse VYS from embryonic days 9 to 12 was examined by light microscopy, electron microscopy and histochemical analysis with benzidine to detect the presence of hemoglobin with special reference to the development of VYS, the disappearance of the blood islands in VYS, and the appearance of a novel structure in the form of erythrocyte-like globules in VYS endodermal cells. The villous appearance of VYS became complicated by the development of VYS endodermal cells. The blood islands positive for the benzidine reaction were light microscopically detected on embryonic days 9, 10, and 11. They disappeared on embryonic day 12, however. Erythrocyte-like globules positive for the benzidine reaction were not observed in VYS endodermal cells on embryonic days 9, 10, and 11, but then appeared on embryonic day 12, by light and electron microscopy. Erythrocyte-like globules in VYS endodermal cells, which appear after the disappearance of blood islands in VYS, may participate in erythropoiesis during embryonic development.

A light and electron microscopic study of the mouse visceral yolk sac endodermal cells in the middle and late embryonic periods, showing the possibility of definitive erythropoiesis

Hematological studies have revealed the importance of the visceral yolk sac (VYS) in the primitive erythropoiesis of mouse embryos at an early stage before day 12. We examined the possibility of the occurrence of extra-embryonic erythropoiesis at a stage later than embryonic day 12 by light and electron microscopic analyses. Surprisingly, a novel structure in the form of erythrocyte-like globules was observed in the VYS endodermal cells. They were consistently present in the VYS endodermal cells from embryonic day 12 until day 18 (birth is day 19), by immunocytochemical and enzyme histochemical analyses. They were immuno-positive for mouse erythrocyte antibody and also positive for the benzidine reaction showing the presence of hemoglobin. The erythrocyte-like globules were shown to be the erythrocytes present in the cytoplasm. These results indicated that erythropoiesis in the VYS endodermal cells continues from the early embryonic stage, as primitive erythropoiesis, until the late stage.

Kinetic Determination of Iodide by the Oxidation Reaction of Benzidine with Chloramine B

A kinetic method was developed for the determination of iodides by their catalytic effect on the oxidation of benzidine with Chloramine B. The determination limit of iodide is 2 × 10–4 μg/mL. It was demonstrated that the proposed method can be used for the determination of iodides in water, soil, and kelp.

Direct evidence of indamine cation radicals in the anodic oxidation of aniline by in situ ESR spectroscopy

The existence of indamine cation radicals in the anodic oxidation of aniline in acidified dimethylsulfoxide (DMSO) is proved by in situ and ex situ ESR spectroscopy. The components of the redox system to form the indamine radicals are studied in DMSO solution by electrochemical in situ ESR spectroscopy, in situ UV-vis spectroscopy and a new triple ESR-UV-vis electrochemistry method. Furthermore, the reaction of benzidine with diphenylamine is investigated for a better understanding of the reaction mechanism. The occurrence of radicals formed in DMSO during electrochemical oxidation is in agreement with the mechanism of the initial stages of electropolymerization of aniline in aqueous solution found by several authors.

Lipolysis in a Belgian sausage: Relative importance of endogenous and bacterial enzymes

The importance of bacterial and meat enzymes in lipolysis and carbonyl formation was evaluated during dry sausage ripening. Sausages were prepared with and without addition of an antibiotic-antimicotic mixture. In some experiments, an extra inoculum of Micrococcaceae was added and in two experiments, glucose was omitted. Total viable bacterial counts after 21 days were lowered by at least 2 log units in the presence of antibiotics. Free fatty acid productions after 3 and 21 days, in the presence of antibiotics were not significantly lower than observed in the control sausages. Total carbonyl compounds (benzidine reaction compounds) were significantly lowered by the presence of antibiotics compared to the control sausages except when glucose was omitted from the recipe. The data suggest that lipolysis is almost exclusively brought about by muscle and fat tissue. Polyunsaturated fatty acids are liberated from the polar lipid fraction and their specific liberation is higher than for monounsaturated and saturated fatty acids. Carbonyl production from lipids seems to be independent of bacterial activity.

Test for occult blood. The benzidine reaction: a text book error

Test for occult blood. The benzidine reaction: a text book error

An FT-IR spectroscopic investigation of the adsorption of benzidine by sepiolite from Eskisehir (Turkey)

The adsorption of benzidine by sepiolite obtained from Eskisehir (Turkey) has been studied by Fourier-transform infrared spectroscopy. A deep green colouration results on reaction of benzidine and sepiolite. In the IR spectrum of benzidine treated sepiolite ν(C-N +) vibrational modes of the uni- and di-positive radical cations are observed in addition to vibrational modes of coordinated benzidine. Spectroscopic results indicate that the principle adsorption mechanism for benzidine is coordination to surface hydroxyls from nitrogen lone pairs and to a relatively small extent, formation of radical cations. No physical sorbed species have been detected. It must be noted that the adsorption of benzidine affected the hydroxyl group vibrations of sepiolite.

HRP reacted with the chromogen o-tolidine produces whole-cell reaction product at light and electron microscope levels: negative effects of sucrose and golgi staining on benzidine reactions

Studies of pathway microcircuitry often require electron microscope analysis. To facilitate these analyses, methods for labeling cells in their entirety are extremely useful. Furthermore, such a method would be most useful if the label would be completely confined by the cell membrane so that second labels for synapse identification could be used. No existing method reliably and repeatably produces this kind of a result. In seeking to develop such a method, a seldom-used chromogen for horseradish peroxidase (HRP) was found which produced superlative results for light and electron microscope analysis. o-Tolidine (3,3′-dimethylbenzidine) reacted with HRP produces a very electron-dense reaction product distributed uniformly throughout the cytoplasm and nucleoplasm; membranes are unobscured so that mitochondria, lysosomes, Golgi apparati and endoplasmic reticula are well defined. The reaction product extends into cellular processes of all sizes, including processes with cell bodies not within the plane of section, and is easily visualized at even the lowest electron microscope magnification. The HRP reaction product is completely confined by the cell membrane, thus terminals presynaptic to labeled cells remain distinct. However, the o-tolidine, the HRP reaction product is negatively affected by exposure to oxidizers. In tissue exposed to sucrose before or after being reacted with o-tolidine, the HRP reaction product is less electron dense and is found only in lysosomes outside the nucleus or occasionally in proximal cellular processes. The o-tolidine/HRP reaction product is similarly affected when exposed to potassium dichromate for Golgi staining. For some other benzidine compounds, the chromogen/HRP reaction product is also negatively affected by exposure to these chemicals. Therefore, o-tolidine is a superior chromogen for HRP, labeling cells with details similar to that found for cells intracellularly injected with HRP.

Development of a radioimmunoassay for RX77368 (pGlu-His-3,3-dimethyl proline amide) — a stable analogue of thyrotrophin releasing hormone (TRH)

The recent interest in RX77368 for the treatment of Motor Neurone Disease (MND) has led to the requirement for an assay (RIA) capable of detecting the peptide at low levels in plasma. Several drug conjugates were prepared in which RX77368 was covalently linked to larger proteins, e.g. bovine serum albumin, keyhole limpet haemocyanin or bovine thyroglobulin, the best yield being obtained with the bis-diazotized benzidine reaction (BDB) linking RX77368 to KLH. The latter conjugate was injected into sheep and ultimately produced an antibody of sufficiently high titre to be used. This combined with an iodinated radiolabel formed the basis of the radioimmunoassay. Cross-reactivity studies using similar analogues and RX77368 metabolites showed that the antibody was specific for RX77368. The greatest cross-reactivity was exhibited by the pGlu-His-monomethylProNH2 peptide (RX74355), but, not being a natural metabolite, this did not interfere with the assay. The RIA was used to measure RX77368 in MND patients in a recent clinical study, where RX77368 was administered both by the intravenous and oral routes. High plasma concentrations of RX77368 were found in the patients given intravenous drug by infusion. The oral route exhibited much lower levels, but had a sustained duration of action of up to 12 h.