Naphthol Blue Black Research Articles

Cellular pharmacological properties of gold(III) porphyrin 1a, a potential anticancer drug lead

The development of gold(III) complexes as potential anticancer drugs with higher cytotoxicity and fewer side effects than existing metal anticancer drugs has been actively pursued in recent years. In this study, we explored the cellular pharmacological properties of gold(III) porphyrin 1a, an anticancer drug lead we previously described. The cytotoxicity study of gold(III) porphyrin 1a by naphthol blue black (NBB) staining assay demonstrated that the higher cytotoxicity of gold(III) porphyrin 1a was not related to its photosensitizing activity. Serum dependent test revealed that serum proteins exhibited lesser effects on the activity of gold(III) porphyrin 1a. In addition, in vivo and in vitro binding assays showed that gold(III) porphyrin 1a acted on DNA noncovalently, which was differently from cisplatin. Flow cytometric study indicated that gold(III) porphyrin 1a inhibited cell growth partly through abrogating cell cycle at G 0–G 1, and induced apoptosis in SUNE1 cells. The enhanced expression of p53, a cell cycle-controlling and apoptosis-related protein, further demonstrated that the cell cycle arrest and apoptosis induced by gold porphyrin 1a were p53 dependent. Our results highlighted the potential of gold(III) porphyrin 1a as an anticancer drug.

Photocatalytic degradation of textile azo dye over Ce1−xSnxO2 series

Ce1−xSnxO2 (x=0, 0.1, 0.2, 0.3 and 1.0) have been prepared by co-precipitation method and characterized by XRD, FTIR, BET surface area and TG/DSC methods. The solid state studies such as electrical resistivity, magnetic susceptibility and diffuse reflectance measurements have been carried out and are attempted to correlate with the photocatalytic activity of these compositions. Solar radiation induced degradation of the textile diazo dye Naphthol Blue Black (NBB) has been carried out on these semiconductor compositions. The surface adsorbed oxygen plays an important role in scavenging photogenerated electrons thus preventing the recombination between electron and hole, inducing effective photodegradation.

Histocytological Analysis of Callogenesis and Somatic Embryogenesis from Cell Suspensions of Date Palm (Phoenix dactylifera)

The date palm is a dioecious perennial species of the Arecaceae for which in vitro micropropagation is essential to ensure the renewal of palm plantations. This study presents a histocytological analysis of the traditional Mauritanian Amsekhsi cultivar beginning from the initial callogenesis and continuing up to the establishment of the cellular embryogenic cell suspensions. The formation of somatic embryos and their development into rooted plants are also described. Foliar segments of seedlings cultured in the presence of 2,4-D produced primary calli that were chopped to produce fine friable granular calli that subsequently produced cellular suspensions when transferred to liquid medium. The somatic proembryos that developed after removal of the 2,4-D were plated on agar medium where they developed into rooted plants. Thin sections of tissue fragments taken at each stage of the process were stained using Periodic Acid Schiff and Naphthol Blue-Black. The first cellular divisions were localized close to the vascular vessels of the leaf. The primary calli were obtained within 2 months. Fine friable granular calli grew quickly after the primary calli were chopped. Individual embryogenic cells were identified that rapidly started to divide and developed into globular proembryos. In addition, in the microcalli, breaking zones appeared in the thick pectocellulosic walls which delimited the pluricellular proembryos. The anatomy of somatic embryos is similar to that of zygotic embryos despite a deficit in the accumulation of intracellular proteins. When rooted with NAA, the vitroplants developed a strong orthotropic taproot. This study contributes to understanding the whole process of somatic embryogenesis, but two specific questions remain to be answered: what factors are involved in the reactivation of the somatic cells at the beginning of the initial callogenesis, and why do the somatic embryos not accumulate proteins in their tissues during maturation?

Decolorization of synthetic dyes by hydrogen peroxide with heterogeneous catalysis by mixed iron oxides

Heterogeneous catalysts based on magnetic mixed iron oxides (MO·Fe2O3; M: Fe, Co, Cu, Mn) were used for the decolorization of several synthetic dyes (Bromophenol Blue, Chicago Sky Blue, Cu Phthalocyanine, Eosin Yellowish, Evans Blue, Naphthol Blue Black, Phenol Red, Poly B-411, and Reactive Orange 16). All the catalysts decomposed H2O2 yielding highly reactive hydroxyl radicals, and were able to decolorize the synthetic dyes. The most effective catalyst FeO·Fe2O3 (25mgmL−1 with 100mmolL−1 H2O2) produced more than 90% decolorization of 50mgL−1 Bromophenol Blue, Chicago Sky Blue, Evans Blue and Naphthol Blue Black within 24h. The fastest decomposition proceeded during the first hour of the reaction. In addition to dye decolorization, all the catalysts also caused a significant decrease of chemical oxygen demand (COD). Individual catalysts were active in the pH range 2–10 depending on their structure and were able to perform sequential catalytic cycles with low metal leaching.

Photocatalytic degradation of dye naphthol blue black in the presence of zirconia-supported Ti-substituted Keggin-type polyoxometalates

Zirconia-supported Ti-substituted Keggin-type polyoxometalates, Li 5PW 11TiO 40/ZrO 2 (PW 11Ti/ZrO 2) and K 7PW 10Ti 2O 40/ZrO 2 (PW 10Ti 2/ZrO 2), were prepared by incorporating PW 11Ti and PW 10Ti 2 cluster into a zirconia matrix via a sol–gel technique. These insoluble and readily separable composites were characterized by DR-UV (DR: diffuse reflectance) and FT-IR spectra, 31 P MAS NMR, ICP-AES, and nitrogen adsorption determination, indicating that the clusters were chemically attached to the zirconia supports, and the primary Keggin structure remained intact. The photocatalytic activity of the supported PW 11Ti and PW 10Ti 2 was tested via degradation of an aqueous dye naphthol blue black (NBB). It indicated that the dye NBB can be degraded totally and mineralized into the inorganic products such as CO 2, NH 4 +, NO 3 −, and SO 4 2− ions by irradiating the composite slurry in the near-UV area. Dropped of PW 11Ti or PW 10Ti 2 cluster from the zirconia matrix into the reaction system was hardly observed during the photocatalytic tests, attributed to the strong chemical interactions between the Keggin units and the zirconia support.

Photoelectrochemical mineralization of textile diazo dye pollutants using nanocrystalline WO 3 electrodes

Photoelectrochemical degradation processes of Naphthol Blue Black (NBB) dye in aqueous solutions were investigated seeking an effective method of degrading textile diazo dyes. Nanocrystalline WO 3 film on a Pt mesh electrode was used as the photoanode for photoelectrochemical degradation of NBB dye. Higher rates of NBB degradation were observed in chloride-containing environments than in sulfate solutions. A strong pH dependence of the NBB dye degradation rate has been found in chloride media. The pH dependence follows the trend of decreasing oxidizing power of electron holes, h VB,s, trapped at the surface of WO 3 particles, with increasing solution pH. In the low pH range (1.0–4.5), photooxidation of the medium favors the formation of Cl and Cl 2 − radicals which are powerful oxidants for the NBB dye. In alkaline solutions, the formation of OH radicals is predominant over Cl and Cl 2 − radicals but the kinetics of NBB degradation is much slower than in acidic media. In sulfate solutions, the rate of NBB photodegradation is slower than in chloride media. Evidently, the lower oxidizing power of the dipersulfate ion S 2O 8 −2 being the oxidant in this environment, is the limiting factor. The intermediates of the NBB dye degradation were detected using HPLC analysis. Possible dye degradation mechanism is proposed.

Synthesis of layered organic–inorganic nanohybrid material: an organic dye, naphthol blue black in magnesium–aluminum layered double hydroxide inorganic lamella

Open lamella systems such as layered double hydroxides (LDHs) can be used to generate new nanostructured materials of layered organic–inorganic nanohybrid type. The synthesis of a new nanocomposite material consisting of inorganic layers, Mg–Al-LDH (MAL) as a host and naphthol blue black (NBB), an organic dye as a guest was successfully done. Various concentrations of NBB, ranging from 0.001 to 0.0015 M were used to prepare the nanocomposite under different Mg/Al molar ratios and pH. The concentration of NBB of 0.0015 M at pH 10 was found to be able to give a well-ordered nanolayered organic–inorganic hybrid structure with basal spacing of 19.6 Å.

Photoelectrochemical degradation of naphthol blue black diazo dye on WO 3 film electrode

Photoelectrochemical degradation of a textile diazo dye, naphthol blue black (NBB), has been investigated using different semiconductor electrodes. A higher photoelectrocatalytic activity has been observed for WO 3 film electrodes, prepared by electrodeposition, than for TiO 2 nanoparticulate film electrodes. By annealing of the WO 3 film deposited on a Pt substrate, we were able to increase the photodegradation rate of NBB, owing to the reduced losses due to the electron–hole recombination. This treatment also increased the long-term photostability of the electrode. The effect of the supporting electrolyte was examined using NaCl, NaClO 4, KNO 3, and Na 2SO 4 solutions. The highest NBB degradation rate was found in the acidic Cl − medium. With increasing solution pH, the degradation rate decreased to a lower level indicating a change in the NBB photodecomposition mechanism. The reaction is of the first order with respect to NBB in the concentration range up to ca. 6×10 −5 M NBB. The apparent rate constants for the photoelectrocatalytic degradation of NBB in 0.5 M NaCl+8.8×10 −5 M NBB solution, on a WO 3 film electrode at E=1.08 V versus SCE, are 1.302×10 −4 and 3.41×10 −5 cm −2 s −1, under illumination with ultraviolet and visible light, respectively. It has been found that the mechanism of the sub-band excitation with the dye self-sensitization is a minor degradation path for NBB, while the main path involves the electron–hole generation and heterogeneous oxidation with participation of valence-band electron holes. The latter reactions involve oxidation of solution components with generation of powerful oxidants, such as the OH , Cl 2 −, and Cl radicals, being directly responsible for the fast dye decomposition.

Kinetic Determination of Nanogram Levels of Manganese(II) by Naphthol Blue Black-Potassium Periodate-1,10-Phenanthroline System

The catalytic effect of manganese(II) on the oxidation of Naphthol Blue Black, with potassium periodate in the presence of 1,10-phenanthroline in weakly acidic media is studied. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance of the dye at 618 nm. Under the optimum conditions (3 × 10−5 mol dm−3 Naphthol Blue Black, 6 × 10−4 mol dm−3 potassium periodate, 1 × 10−4 mol dm−3 1,10-phenanthroline, 0.1 mol dm−3 acetate buffer – pH 4.0, 60 °C, 5 min) manganese(II) in the range 0.08–4 ng cm−3 can be determined by the fixed-time method with a detection limit of 0.025 ng cm−3. The influence of foreign ions on the accuracy of the results is investigated. The developed method is highly sensitive, selective, and simple. The method was applied successfully to the determination of manganese in cucumbers, garlic cloves and parsley leaves.

Combinative Sonolysis and Photocatalysis for Textile Dye Degradation

The merits of combining two advanced oxidation processes, viz., sonolysis and photocatalysis, have been evaluated by investigating the degradation of an azo dye, naphthol blue black (NBB), using a high-frequency ultrasonic generator and UV−photolysis. An additive effect on the degradation rate of the parent compound is observed when the sonolysis and photocatalysis experi ments were carried out in a simultaneous or sequential manner. Sonolysis is effective for inducing faster degradation of the parent dye, while TiO2 photocatalysis is effective for promoting mineralization.

Photocatalytic reduction of azo dyes Naphthol Blue Black and Disperse Blue 79

Photocatalytic reduction of two textile azo dyes, Naphthol Blue Black (NBB) and Disperse Blue 79 (DB79) has been carried out in colloidal WO3 and TiO2 suspensions. Under bandgap excitation of the semiconductor colloids these dyes undergo irreversible reduction as they react with the trapped electrons. The quantum efficiency for the photocatalytic reduction of these dyes were 5.4% and 4.8% for NBB and DB79 respectively. The kinetics and mechanism of the interfacial charge transfer in these colloidal suspension has been elucidated with transient absorption spectroscopy. The reaction between the dye and trapped electrons is diffusion limited and occurs with rate constants of 1.1×108 M−1s−1 and 4.0×107 M−1s−1 for NBB and DB79 respectively.

Excited states and reduced and oxidized forms of a textile diazo dye, naphthol blue black. Spectral characterization using laser flash photolysis and pulse radiolysis studies

The excited singlet and triplet states of a diazo textile dye (Naphthol Blue Black) have been investigated by pico and nanosecond flash photolysis. The excited singlet state shows a difference absorption maximum at 500 nm and has a lifetime of 25–30 ps in ethanol. The triplet excited state generated by triplet-triplet energy transfer shows an absorption maxima at 710–730 nm. The oxidized form as well as the reduced form of the diazo dye have been generated pulse radiolytically by reacting with azide and e aq radicals, respectively. Preliminary results of the photoelectrochemical irreversible reduction of Naphthol Blue Black in colloidal TiO 2 are also reported.

Environmental Photochemistry on Semiconductor Surfaces. Visible Light Induced Degradation of a Textile Diazo Dye, Naphthol Blue Black, on TiO2 Nanoparticles

Visible light induced degradation of the textile diazo dye Naphthol Blue Black (NBB) has been carried out on TiO2 semiconductor nanoparticles. Diffuse reflectance transient absorption and FTIR techniques have been used to elucidate the mechanistic details of the dye degradation. The failure of the dye to degrade on insulator surfaces such as Al2O3 or in the absence of oxygen further highlights the importance of semiconducting properties of support material in controlling the surface photochemical processes. The primary event following visible light excitation is the charge injection from the excited dye molecule into the conduction band of the semiconductor TiO2, producing the dye cation radical. This was confirmed by diffuse reflectance laser flash photolysis. The surface-adsorbed oxygen plays an important role in scavenging photogenerated electrons, thus preventing the recombination between the dye cation radical and photoinjected electrons. Diffuse reflectance FTIR study facilitated identification of r...

Nanostructured Semiconductor Films for Photocatalysis. Photoelectrochemical Behavior of SnO2/TiO2Composite Systems and Its Role in Photocatalytic Degradation of a Textile Azo Dye

Nanostructured semiconductor films of SnO2, TiO2 and SnO2/TiO2 have been employed for electrochemically assisted photocatalytic degradation of a textile azo dye naphthol blue black (NBB). The degradation rate is significantly higher for SnO2/TiO2 composite films than SnO2 and TiO2 films alone. An effort has been made to correlate the photoelectrochemical behavior of these films to the rate of photocatalytic degradation of NBB. The enhanced degradation rate of NBB using composite semiconductor films is attributed to increased charge separation in these systems. Photoelectrochemical and photocatalytic degradation experiments carried out in both nitrogen- and oxygen-saturated solutions with an externally applied electrochemical bias provide useful information in optimizing semiconductor concentrations in a composite film.

Sorption—desorption studies of anionic dyes on alumina pretreated with acids

Sorption—desorption behaviour of the anionic dyes naphthol blue-black (NB) and lissamine green ‘BN’ (LG) on chromatographic alumina, pretreated with mineral acids, is described. Alumina samples of surface-phase pH 1.0–8.0 were prepared and studied for their sorption behaviour. The sorption was found to vary with surface pH of the substrate and acid used for pretreatment. Quantitative sorption was shown at pH ⩽ 4.0 (NB) and pH ⩽ 3.5 (LG) on Al 2O 3 treated with HNO 3 [Al 2O 3(n)], and maximum sorption occurred at pH 5.0 (NB) and pH 5.5 (LG) on Al 2O 3 treated with H 2SO 4 [Al 2O 3(s)] and pH 2.5 (NB) and pH 3.0 (LG) on Al 2O 3 treated with H 3PO 4 [Al 2O 3(p)]. Variation in sorption with time (10 min-72, h), temperature (30–60°C) and regeneration of the substrates with aqueous electrolytes is also reported. Desorption efficacy of anions was in the order: PO 3− 4 > SO 2− 4 > NO − 3. The acid-treatment, and hence the specifically adsorbed anions (NO − 3, SO 2− 4, PO 3− 4), appears to modify the sorption properties of alumina significantly. It appears that the controlling force for adsorption is predominantly ion exchange. A few synthetic mixtures of the dyes were separated by column chromatography, using inorganic electrolytes as eluents.

Spectrophotometric quantitation of anchorage-dependent cell numbers using extraction of naphthol blue-black-stained cellular protein

A convenient method is described by which the actual or relative number of cells in anchorage culture is determined. After removal of the growth medium, cells are subjected to a double-fixation procedure. The cellular protein content is subsequently quantitatively stained with naphthol blue-black. After a period of removal of unbound stain, dye-protein complexes are hydrolytically released and measured spectrophotometrically at 620 nm. A linear correlation exists ( r = 0.994) between cell concentration, in the range 3 × 10 4 to 8 × 10 5 cells/ml of final assay volume, and absorbance up to reading values of 3.8. The technical reproducibility of the assay, as judged from assessments of cell numbers in suspension culture, displays a coefficient of variation of 5%. The method was developed for 9.6-cm 2 culture dishes, but it should be possible to transform it for the use of microtiter plates.

Detection of polyhedra from insect virus diseases on filter membranes.

Polyhedra filtered directly from the air or from aqueous suspensions by means of Millipore filter membranes, are stained on the membranes as follows: To a microscope slide mount consisting of a small piece of membrane filter on which the polyhedra are retained, are added 1 drop of a 1:4 dilution of saturated aqueous picric acid and 1 drop of staining solution: 0.1 gm of naphthol blue-black, C.I. 246 (Hartman-Leddon Co.) dissolved in a mixture of 98% methanol, 5; distilled water, 4 and glacial acetic acid, 1—parts by volume (Grosset et al. Proc. Soc. Exp. Biol. Med., 97, 72-7, 1958). The slide is placed on a hot plate at 600° C (dull red heat) until evaporation takes place and the filter membrane turns blue. Before the membrane begins to burn, the slide is removed and allowed to cool. For stain-sensitive polyhedra the above procedure is adequate. However, for stain-resistant polyhedra it is sometimes necessary to heat the mount with the picric acid alone, followed by the stain and a second heating. For hig...