Presence Of Sodium Bicarbonate Research Articles

Production and characterization of biodiesel from carbon dioxide concentrating chemolithotrophic bacteria, Serratia sp. ISTD04

A chemolithotrophic bacterium, Serratia sp. ISTD04, enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was evaluated for potential of carbon dioxide (CO2) sequestration and biofuel production. CO2 sequestration efficiency of the bacterium was determined by enzymatic activity of carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Further, Western blot analysis confirmed presence of RuBisCO. The bacterium produced 0.487 and 0.647mgmg(-1) per unit cell dry weight of hydrocarbons and lipids respectively. The hydrocarbons were within the range of C13-C24 making it equivalent to light oil. GC-MS analysis of lipids produced by the bacterium indicated presence of C15-C20 organic compounds that made it potential source of biodiesel after transesterification. GC-MS, FTIR and NMR spectroscopic characterization of the fatty acid methyl esters revealed the presence of 55% and 45% of unsaturated and saturated organic compounds respectively, thus making it a balanced biodiesel composition.

Synthesis, characterization, and electrochemical study of a new tetradentate nickel(II)-Schiff base complex derived from ethylenediamine and 5′-(N-methyl-N-phenylaminomethyl)-2′-hydroxyacetophenone

A tetradentate Schiff base ligand (3) has been synthesized via the reaction of 5′-(N-methyl-N-phenylaminomethyl)-2′-hydroxyacetophenone (2) with a stoichiometric amount of ethylenediamine in absolute ethanol. Compound 2 was prepared by reaction of 5′-chloromethyl-2′-hydroxyacetophenone (1) with N-methylaniline, in the presence of sodium bicarbonate in tetrahydrofuran. Compound 1, on the other hand, was obtained through a reaction between a hydrochloric acid–formaldehyde mixture and 2′-hydroxyacetophenone. Refluxing a mixture of the Schiff base (3) and a stoichiometric amount of nickel(II) acetate tetrahydrate in absolute ethanol at 50°C under a nitrogen atmosphere afforded the expected tetradentate nickel(II)-Schiff base coordination compound (4). Compounds 1–4 have been characterized with the aid of a number of techniques: UV–Vis spectrophotometry; FT-IR, 1H NMR, 13C NMR, and mass spectrometry; and elemental analysis. Cyclic voltammetry has been employed to investigate the redox behavior of compound 4 as well as the ability of the electrogenerated nickel(I) form of 4 to catalyze the reduction of 1-iodooctane.

Diorganotin(IV) Derivatives of N-Methyl p-Fluorobenzo-Hydroxamic Acid: Preparation, Spectral Characterization, X-ray Diffraction Studies and Antitumor Activity

Three diorganotin(IV) complexes of the general formula R2Sn[RcC(O)N(RN)O] (Rc = aryl, RN = Alkyl) have been synthesized by refluxing in toluene the corresponding diorganotin(IV) oxides with the free ligand N-methyl p-fluorobenzohydroxamic acid, using a Dean and Stark water separator. The ligand was derived from the reaction of the corresponding p-fluorobenzoyl chloride and N-methylhydroxylamine hydrochloride in the presence of sodium hydrogen carbonate. The isolated free ligand and its respective diorganotin compounds have been characterized by elemental analysis, IR and 1H-, 13C-, 119Sn-NMR spectroscopies. The crystal structures of the diorganotin complexes have been confirmed by single crystal X-ray diffraction methods. The investigations carried out on the diorganotin(IV) complexes of N-methyl p-fluorobenzohydroxamic acid confirmed a 1:2 stoichiometry. The complex formation took place through the O,O-coordination via the carbonyl oxygen and subsequent deprotonated hydroxyl group to the tin atom. The crystal structures of three diorganotin complexes were determined and were found to adopt six coordination geometries at the tin centre with coordination to two ligand moieties.

New Ecofriendly Validated Spectrophotometric Method For The Estimation Of Amlodipine Besylate In Bulk Drug Using Ninhydrin

A new, accurate, precise and economical spectrophotometric method has been developed and validated for the determination of Amlodipine Besylate in bulk drugs. This method is based on the reaction of ninhydrin with primary amine present in the Amlodipine Besylate in the presence of Sodium Bicarbonate. This reaction proceeds quantitatively at 97 � 1�C in 15 min and produces a purple color product which absorbs maximally at about 566 nm. Beer-Lambert?s law is obeyed in the concentration range of 50-250?g/ml and is described by the regression equation Y = 0.700x - 0.20 with a regression coefficient (r2 ) = 0.999 (n = 6). The effects of variables such as temperature, heating time, concentration of colour producing reagent and stability of colour were investigated to optimize the procedure. For Amlodipine Besylate, the value of molar absorptivity and Sandell?s sensitivity are 3.1077 x 103 L/mol/cm and 0.1824?g/cm2 , respectively and of LOD and LOQ are found to be 0.09 and 0.2729?g/ml, respectively. The statistically validated results indicate that the proposed method has good sensitivity, accuracy, precision and stability. The method is eco friendly and economic as it does not involve a any organic solvents.

Carboxyterfenadine antacid interaction monitoring by UV spectrophotometry and RP-HPLC techniques

Carboxyterfenadine, a primary metabolite of terfenadine, a second generation antihistaminic compound was introduced in therapy as a successor of terfenadine due to its cardiac arrhythmia. There are number of drug interactions of fexofenadine with erythromycin, ketoconazole and alike reported in the literature. In this paper, fexofenadine antacid interaction has been studied in presence of sodium bicarbonate, megaldrate, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium trisilicate, simethicone (dimethylpolysiloxane) and calcium hydroxide by UV–Vis spectrophotometer and high performance liquid chromatography (HPLC). These in vitro fexofenadine–antacid interactions were carried out in simulated gastric and intestinal juices and in buffer of pH 7.4 (simulating blood pH) on BP 2005 dissolution apparatus. The results show non-concordant availability of fexofenadine envisaged due to formation of unstable charge transfer complexes.

Selective Synthesis of Cyano-Functionalized 2-Aryl-4H-chromenes and 2-Amino-4H-chromene-3-carbonitriles by Catalyst-Tuned Reactions of 2-Hydroxychalcones with 2-Substituted Acetonitriles

A selective synthesis of 4H-chromenes by the reactions of 2-hydroxychalcone derivatives with acetonitriles substituted with electron-withdrawing groups is described. Under catalyst-free conditions, the reactions give cyano-functionalized 2-aryl-4H-chromenes, whereas in the presence of sodium bicarbonate, 2-amino-4H-chromene-3-carbonitriles are obtained in excellent yields.

Polymer–clay nanocomposites via chemical grafting of polyacrylonitrile onto cloisite 20A

The synthesis and characterization of polyacrylonitrile (PAN) nanocomposites through grafting the polymer onto organophilic montmorillonite have been reported. Cloisite 20A reacted with vinyltrichlorosilane to replace the edge hydroxyl groups of the clay with a vinyl moiety. Because the reaction liberates HCl, it was performed in the presence of sodium hydrogen carbonate to prevent the exchange of quaternary alkylammonium cations with H + ions. Only the silanol groups on the edge of the clay reacted with vinyltrichlorosilane. The radical polymerization of the product with acrylonitrile (AN) as a vinyl monomer leads to chemical grafting of polyacrylonitrile onto montmorillonite surface. The homopolymer formed during polymerization was separated from the grafted organoclay by Soxhlet extraction. Chemical grafting of the polymer onto Cloisite 20A was confirmed by infrared spectroscopy. The prepared nanocomposite materials and grafted nanoparticles were studied by XRD and TEM. Exfoliated nanocomposites were obtained for 0·5–7 wt% clay content. The nanocomposites were studied by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMTA).

Nanocomposite materials based on isosorbide methacrylate/Cloisite 20A

AbstractThis paper reports experiments on grafting of a new polymerizable monomer onto organophilic montmorillonite. The monomer, 5‐methacryloyloxy‐1,4:36‐D‐anhydrosorbitol (MAS), was synthesized by reacting methacryloyl chloride and isosorbide in the presence of Et3N as base. Then, Cloisite 20A was reacted with vinyltrichlorosilane to replace the edge hydroxyl groups of the clay with a vinyl moiety. Because the reaction liberates HCl, it was performed in the presence of sodium hydrogen carbonate to prevent the exchange of quaternary alkylammonium cations with H+ ions. Only the silanol groups on the edge of the clay react with vinyltrichlorosilane. After the reaction, the product maintained the same basal spacing as the precursor. The radical polymerization of the product with MAS as a vinyl monomer led to chemical grafting of the polymer onto the montmorillonite surface. The homopolymer formed during polymerization was separated from the grafted organoclay by Soxhlet extraction. Chemical grafting of the polymer onto Cloisite 20A was confirmed using infrared spectroscopy. The prepared nanocomposite materials and the grafted nanoparticles were studied using X‐ray diffraction and scanning and transmission electron microscopy. Exfoliated nanocomposite was obtained for 1 wt% clay loadings. The nanocomposites were studied using thermogravimetric and dynamic mechanical analyses. Improved thermal properties were observed for nanocomposites with 1–5 wt% clay content. © 2012 Society of Chemical Industry

Growth of one-dimensional single-crystalline hydroxyapatite nanorods

A facile, effective and template/surfactant-free hydrothermal route in the presence of sodium bicarbonate was developed to synthesize highly uniform single-crystalline hydroxyapatite (HA) nanorods with the lengths of several hundred nanometers and aspect ratio up to ∼20. One dimensional (1-D) growth and aspect ratio could be controlled by hydrothermal reaction time and temperature. The longitudinal axis, also the growth direction of the nanorods, is parallel to the [001] direction of HA hexagonal crystal structure.

ChemInform Abstract: Synthesis, Structure Characterization, and X‐Ray Crystallography of Novel 1‐Benzyl‐3‐phenyl‐1H‐pyrazole‐5‐carboxylate Derivatives with a Carbohydrate Moiety.

AbstractTitle derivatives (III) are prepared by the reaction of the acetylated α‐D‐xylopyranosyl bromide and the corresponding pyrazole‐based carboxylic acid in the presence of sodium bicarbonate and tetrabutylammonium bromide in moderate yields.

Sonochemical degradation of alachlor in the presence of process intensifying additives

The sonochemical degradation of alachlor has been investigated using ultrasonic horn. Initially the effect of operating initial pH has been investigated over the range of 2–11 followed by the effect of different intensifying additives such as hydrogen peroxide and carbon tetrachloride. It has been observed that acidic conditions favor degradation and also both the additives result in enhanced extent of degradation. The combination of ultrasonic horn with conventional Fenton and advanced Fenton process was also investigated. With an objective of deciphering the controlling mechanism for the sonochemical degradation, the effect of addition of hydroxyl radical scavengers such as sodium bicarbonate and n-butanol has been studied and it has been observed that the degradation of alachlor is strongly inhibited in the presence of sodium bicarbonate and n-butanol due to the free radical scavenging effect. Some preliminary experiments have been performed at larger scales of operation to check the efficacy of sonochemical reactors for large scale application. Kinetic studies revealed that all the systems under investigation followed first order degradation except US/Fenton and US/advanced Fenton where second order kinetics was observed. Analysis of the intermediate products of the alachlor degradation process has also been made using LC–MS.

Native, but not thermally denatured lactoferrin solubilizes iron in the presence of bicarbonate ions

Lactoferrin (Lf) can solubilize more than a 70-fold molar equivalent of iron in the presence of bicarbonate anions. Iron solubilized by Lf (FeLf) is a useful food product for iron fortification, preventing anaemia with no risk of toxicity. However, the mechanism underlying this iron solubilization is not yet well understood. The objective of this study was to investigate the effects of thermal treatments on the iron-solubilizing capacity of Lf in the presence of sodium bicarbonate. Lf was subjected to thermal treatment at 50–80 °C for 10 min, and the Lf heated to over 70 °C was precipitated by the addition of Fe(III). No precipitation was observed in FeLf-like mixtures of heated Lf when various other cations were substituted for Fe(III): Cu(II), Zn(II), Mg or Na. The precipitation was related to the degree of thermal denaturation of Lf, accompanied by the formation of high-molecular-weight aggregates as disulphide bonds were established. Transferrin, α-lactalbumin and β-lactoglobulin did not solubilize Fe(III), suggesting that the Fe(III)-solubilizing capacity is characteristic of Lf. In conclusion, native Lf is responsible for iron solubilization in the presence of bicarbonate anions. Owing to the application of native Lf to the manufacture of FeLf, FeLf can improve specific food products by supplementing their iron content.

Synthesis of Pyrazoles via Electrophilic Cyclization

Electrophilic cyclizations of α,β-alkynic hydrazones by molecular iodine were investigated for the synthesis of 4-iodopyrazoles. α,β-Alkynic hydrazones were readily prepared by the reactions of hydrazines with propargyl aldehydes and ketones. When treated with molecular iodine in the presence of sodium bicarbonate, α,β-alkynic hydrazones underwent electrophilic cyclization to afford 4-iodopyrazoles in good to high yields. Iodocyclization was general for a wide range of α,β-alkynic hydrazones and tolerated the presence of aliphatic, aromatic, heteroaromatic, and ferrocenyl moieties with electron-withdrawing and electron-donating substituents.

The Synthesis and Characterization of s-Triazine-Cored and [Fe(III)Salen]-Capped Polymer Complexes

2,4,6-Trichloro-1,3,5-triazine (cyanuric chloride, C3N3Cl3, 1) was used as the starting material. 2-(4-Carboxyphenylamino)-4,6-dichloro-1,3,5-triazine (2) was obtained from the reaction of cyanuric chloride with 4-aminobenzoic acid in the presence of sodium bicarbonate in acetone. A mononuclear complex (4) was obtained by reacting 2 and [FeSalen]2O (3). A series of polymeric compounds was obtained by reacting 4 with a series of diamines. The polymeric complexes were characterized by elemental analysis, AAS, FT-IR, 1H NMR, TGA and magnetic susceptibility measurements. The complexes are low-spin, distorted octahedral Fe(III) species that are bridged by carboxylic acids. The [FeSalen]-containing compounds may have the electronic structure t 2g 5 e g 0 . All the complexes have six coordination and are polymeric.

Ceftazidime-hydrolysing -lactamase OXA-145 with impaired hydrolysis of penicillins in Pseudomonas aeruginosa

To describe a novel extended-spectrum oxacillinase, named OXA-145, differing from narrow-spectrum OXA-35 (from the OXA-10 group) by deletion of residue Leu-165. The genetic environment of bla(OXA-145) and the biochemical properties of OXA-145 are reported. We also assessed the impact of the Leu-165 deletion on the hydrolysis spectrum of the ancestor OXA-10. Extended-spectrum β-lactamase OXA-145 was identified in the multidrug-resistant clinical Pseudomonas aeruginosa 08-056, and characterized by isoelectric focusing, PCR and DNA sequencing. Antibiotic susceptibility tests were performed by agar dilution. The resistance profiles conferred by cloned bla(OXA-10), bla(OXA-35), bla(OXA-145) and a bla(OXA-10) derivative obtained by site-directed mutagenesis were determined in Escherichia coli. Kinetic parameters of OXA-35 and OXA-145 were established after purification of His-tagged proteins. The sequence of OXA-145, encoded by a class 1 integron-borne gene in strain 08-056, differed from that of narrow-spectrum penicillinase OXA-35 by a single amino acid deletion (Leu-165) located in the highly conserved omega loop. Deletion of Leu-165 from OXA-35 (yielding OXA-145) or OXA-10 (the progenitor of OXA-35) extended the hydrolysis spectrum to third-generation cephalosporins and to monobactams, while reducing that for penicillins. OXA-145 showed biphasic hydrolysis curves for all the substrates tested. Its activity against nitrocefin was 10-fold higher in the presence of sodium hydrogen carbonate. OXA-145 is a new extended-spectrum β-lactamase from the OXA-10 group. The deletion of Leu-165 is responsible for a shift in the hydrolysis spectrum from penicillins to third-generation cephalosporins, as well as monobactams. The loss of penicillin hydrolysis was due to a non-carboxylated Lys-73.

Dyeing of Silk/PLA Mixture with Reactive Dyes

Silk/PLA mixture is a new textile material, and it combines the outstanding characteristics of silk and PLA fibers. During the wet process, this mixture is subjected to some problems owing to the poor resistance of PLA fiber to alkali. The silk component in this mixture can be dyed with acid dyes under acidic condition, and with reactive dyes under alkaline condition. In the present work, silk/PLA mixture was dyed with Everzol ED reactive dyes in the case of the use of sodium carbonate and sodium bicarbonate as alkalis for the fixation of dyes. The alkali dosage and dyeing temperature on the uptake of dyes by this mixture were discussed. Also, the dyeing rates, building-up properties and color fastness of reactive dyes were determined. It was found that Everzol ED reactive dyes exhibited good dyeing properties for silk/PLA mixture under weakly alkaline condition in the presence of sodium bicarbonate.

Smart gelation of chitosan solution in the presence of NaHCO 3 for injectable drug delivery system

In situ gelling systems are attractive as injectable vehicles for drug delivery. The present work described a novel gelation process of acidic chitosan solution in the presence of sodium bicarbonate (NaHCO 3). The NaHCO 3 concentration played an important role in this gelling system. When it came within the appropriate range, the chitosan/NaHCO 3 system would stay at sol state in certain condition and showed sol–gel transition from the top to the bottom after heating. The rheological properties of the gelling system, as well as the morphology and erosion behavior of the formed chitosan hydrogels were evaluated as a function of the NaHCO 3 concentration in sols. The hydrogels showed porous morphologies with some diversification depending on the NaHCO 3 concentration, which also affected their erosion behaviors and drug release rates. Moreover, the gelation mechanism of such chitosan/NaHCO 3 system was studied and proposed as the formation of three-dimensional chitosan network with physical junctions thanks to the deprotonation of –NH 3 + in chitosan accompanying with the gradual neutralization between HCO 3 − and acid. In vivo gelation test was also performed by the dorsal subcutaneous injection of chitosan/NaHCO 3 solution in rat. The formation of in situ gels suggested such system promising applications in injectable drug delivery system.

Synthesis, Structure Characterization, and X-ray Crystallography of Novel 1-Benzyl-3-phenyl-1H-pyrazole-5-carboxylate Derivatives with a Carbohydrate Moiety

A series of novel (2S,3R,4S,5R)-3,4,5-triacetoxy-tetrahydro-2H-pyran-2-yl 1-benzyl-3-phenyl-1H-pyrazole-5-carboxylate derivatives (3) were synthesized by the reaction of 2,3,4-tri-O-acetyl-α-D-xylopyranosyl bromide (2) and 1-benzyl-3-phenyl-1H-pyrazole-5-carboxylic acid (1) in the presence of sodium bicarbonate and tetrabutylammonium bromide in dichloromethane at reflux temperature. The structures of new compounds were determined by IR and 1H NMR spectroscopy and HR mass spectrometry (HRMS), and the configuration of the newly generated chiral carbon (C-1) in the xylose ring was tentatively assigned based on the X-ray crystallographic structure of 3d and 3g.

Characterisation of Norway spruce hemicelluloses extracted by pressurised hot-water extraction (ASE) in the presence of sodium bicarbonate

AbstractGround spruce sapwood was extracted with pressurised hot water with addition of different amounts of sodium bicarbonate (NaHCO3) to find optimal pH conditions for extraction of hemicelluloses, especially of galactoglucomannans (GGMs). The extractions were carried out in an accelerated solvent extractor (ASE) at 170°C. When extraction was carried out with 2.5 mM NaHCO3during 60–100 min extraction time (end-pH 3.9), more than 60% of the total extracted substances were hemicellulose-derived carbohydrates. Under these conditions, approximately 80% of the extracted carbohydrates were from GGMs (13% b.o. wood). At higher concentrations of NaHCO3, the yield of carbohydrates, especially those derived from GGMs, decreased. Hydrolytic depolymerisation of hemicelluloses occurring during extraction with plain water was largely inhibited in the presence of 2.5–5 mM NaHCO3. The hydrolytic deacetylation of GGM was diminished at low NaHCO3concentrations but increased dramatically at higher NaHCO3concentrations. It can be concluded that 2.5–5 mM NaHCO3giving an end-pH value of 4 is better for GGM isolation than plain water.

Chemiluminescence behavior of sodium hydrogen carbonate in the potassium permanganate-hydrogen peroxide reaction

Chemiluminescence (CL) phenomenon of hydrogen peroxide with potassium permanganate in the presence of sodium hydrogen carbonate was reported. Effects of the surfactant on the CL system were investigated. Nonionic surfactants could effectively increase the CL signal. Radical scavengers and organic reagents such as nitro blue tetrazolium chloride (NBT), cytochrome c, sodium azide, ascorbic acid, thiourea, tert-butanol and dimethyl sulphoxide were used to study the emitting species. CL emission spectrum was recorded and the results showed that the maximal emission wavelengths of NaHCO3-H2O2-KMnO4 system were 440 and 634 nm. The mechanism was discussed based on electron spin resonance (ESR) spectra, fluorescence spectra and UV-vis absorption spectra. The addition of rhodamine B or uranine into this CL system enhanced the CL signal. It was due to part of the energy transfer from singlet oxygen and excited triplet dimers of two CO2 molecules to rhodamine B or uranine. The CL could be induced by excited rhodamine B or uranine.