Presence Of NaHCO3 Research Articles

Transcriptome dynamics and hub genes of green alga Nannochloris sp. JB17 under NaHCO3 stress

Soil salinization and alkalization are major problems in crop production. To gain insights into the mechanisms of saline-alkaline tolerance, we investigated the molecular response of a highly stress tolerant green alga, Nannochloris sp. JB17 (JB17) to NaHCO3. Results indicated that JB17 cells retain a high level of cell viability when subjected to a high concentration (300 mM) of NaHCO3. A transcriptome analyses was conducted of JB17 cells that were subjected to either 50 mM or 300 mM NaHCO3 for 4 h, 24 h or 72 h. Thousands of differentially expressed genes (DEGs)11DEGs: Differentially expressed genes. were identified, among which, 134 highly expressed DEGs were mainly enriched in photosynthesis-related processes. Gene co-expression analysis revealed the unique molecular profile of JB17 cells subjected to NaHCO3 stress. Detailed analyses of the long-term and high concentration NaHCO3 related modules indicated that the key pathways and hub genes were related to antioxidant capacity, carbohydrate metabolism, and cell division. Corresponding physiological experiments revealed that the antioxidant enzymes activity and the population of palmelloid cells significantly increased in JB17 cells under NaHCO3 stress. Our data indicate that JB17 cells actively support photosynthesis and increase reactive oxygen species scavenging activity to survive in the presence of NaHCO3. These results provide information on the regulatory mechanisms associated with saline-alkaline tolerance in Nannochloris.

Design, synthesis, molecular docking study, and antibacterial evaluation of some new fluoroquinolone analogues bearing a quinazolinone moiety.

Increasing bacterial resistance to quinolones is concerning. Hence, the development of novel quinolones by chemical modifications to overcome quinolone resistance is an attractive perspective in this context. In this study, it is aimed to design and synthesize a novel series of functionalized fluoroquinolones using ciprofloxacin and sarafloxacin cores by hybridization of quinazolinone derivatives. This objective was tested by a comprehensive set of in vitro antibacterial assays in addition to SAR (structure-activity relationship) characterisation studies. A nucleophilic reaction of ciprofloxacin and sarafloxacin with 2-(chloromethyl)quinazolin-4(3H)-one in the presence of NaHCO3 in dimethylformamide (DMF) was performed to obtain the desired compounds 5a-j. Novel compounds were characterised by 1H, 13C- NMR and IR spectroscopy, MS and elemental analysis. In silico pharmacokinetics prediction assays and molecular docking studies were performed to explore the binding characteristics and interactions. Antibacterial activities of the novel compounds were evaluated by Broth microdilution, well diffusion and disc diffusion assays against three gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus and Enterococcus faecalis) and three gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli). The compounds exhibited moderate to good activities against gram-positive bacteria and weak to moderate activities against gram-negative bacteria. Amongst all ciprofloxacin-derivatives, compound 5d was the most potent agent with high antibacterial activity against gram-positive bacteria, including MRSA and S. aureus ((minimum inhibitory concentration (MIC) = 16nM for both), that is 60 times more potent than ciprofloxacin as parent drug. Compound 5i from sarafloxacin-derivatives was the most potent compound against MRSA and S. aureus (MIC = 0.125μM). Well diffusion and disk diffusion assay results demonstrated confirmatory outcomes for the quantitative broth microdilution assay. Molecular docking study results were in accordance with the results of antibacterial activity assays. The results of the current study demonstrated that the novel ciprofloxacin and sarafloxacin derivatives synthesized here have promising antibacterial activities. Particularly, compounds 5d and 5i have potential for wider antibacterial applications following further analysis.

A ternary Cu2O/BiVO4/WO3 nano-composite: Scavenging agents and the mechanism pathways in the photodegradation of sulfasalazine

As prepared visible-light-sensitive Cu2O/BiVO4/WO3 nano-composite (NC) was used in the photocatalytic degradation of SFSZ (sulfasalazine). The XRD, UV–Vis DRS, SEM, and photoluminescence (PL) techniques were used to characterize the composite. The Crystallite size of the composite was estimated by the Williamson-Hall model around 10.7 nm. A lower PL intensity of the composite than the individual semiconductors confirmed that the rate of electron/hole recombination in the composite is lower than those of individual components. The composite also represented an increased photocatalytic activity with respect to the individual system. During 30 min of photodegradation experiment, about 50%, 3%, 19%, and 67% SFSZ molecules were removed by the individual Cu2O, BiVO4, WO3 semiconductors, and Cu2O-BiVO4-WO3 NC (with a mole ratio of 1:1:1), respectively. Among the prepared nano-composites with different mole ratios, the NC with a Cu2O:BiVO4: WO3 mole ratio of 2:1:1 demonstrated the lowest PL intensity and the highest degradation activity. The effects of some scavenging agents including potassium peroxydisulfate (electron scavenger), potassium oxalate (hole scavenger), sodium bicarbonate, and carbonate (OH scavenger) and ascorbic acid (AA as O2− scavenger) were also studied in detail. The results showed that 80% degradation efficiency by the NC that amplified up to 94% and 97% in the presence of K2S2O8 and bicarbonate but decreased to 62.5%, 19%, and 6.5% in the presence of NaHCO3, KC2O4, and AA, respectively. The results confirmed the pivotal role of superoxide radicals in the degradation process. Among the ‘cascade’ and ‘Z-scheme’ mechanisms, the ‘Z-scheme’ one had a vital role to illustrate the photodegradation pathway of the ternary composite.

Bis(phenoxy-imine) ruthenium(II) carbonyl complexes: syntheses, structures and their catalytic activities for conversion of aldehydes to nitriles

Three new ruthenium(II) carbonyl complexes that bear phenoxy-imine chelate ligands, [RN = CH(C6H4O)]2Ru(CO)2 (1: R = 2,6-Me2C6H3; 2: R = 4-OMeC6H4; 3: R = 4-ClC6H4) have been synthesized. These mononuclear ruthenium(II) complexes were fully characterized by elemental analysis, FT‒IR, and 1H and 13C NMR. Furthermore, the molecular structures of 1-3 were determined by X-ray crystal diffraction analysis. In the presence of NaHCO3 as the base, the Ru carbonyl complexes showed moderate to good catalytic activities for the conversion of aldehydes to nitriles via the dehydration of aldoximes.

3Pa4-1 Enhancement of Sono-oxidation Rate in the Presence of NaHCO3

3Pa4-1 Enhancement of Sono-oxidation Rate in the Presence of NaHCO₃

Visible-Light Activated Titania and Its Application to Photoelectrocatalytic Hydrogen Peroxide Production.

Photoelectrochemical cells have been constructed with photoanodes based on mesoporous titania deposited on transparent electrodes and sensitized in the Visible by nanoparticulate CdS or CdS combined with CdSe. The cathode electrode was an air–breathing carbon cloth carrying nanoparticulate carbon. These cells functioned in the Photo Fuel Cell mode, i.e., without bias, simply by shining light on the photoanode. The cathode functionality was governed by a two-electron oxygen reduction, which led to formation of hydrogen peroxide. Thus, these devices were employed for photoelectrocatalytic hydrogen peroxide production. Two-compartment cells have been used, carrying different electrolytes in the photoanode and cathode compartments. Hydrogen peroxide production has been monitored by using various electrolytes in the cathode compartment. In the presence of NaHCO3, the Faradaic efficiency for hydrogen peroxide production exceeded 100% due to a catalytic effect induced by this electrolyte. Photocurrent has been generated by either a CdS/TiO2 or a CdSe/CdS/TiO2 combination, both functioning in the presence of sacrificial agents. Thus, in the first case ethanol was used as fuel, while in the second case a mixture of Na2S with Na2SO3 has been employed.

Synthesis of daunorubicin conjugates with fragments of H type 5, Lea, Lex antigens and N-fucoglycan

Daunorubicin was conjugated with spacered N-glycosides of di- and trisaccharides containing terminal α-l-fucopyranose residues. The synthesis was carried out by N-monoalkylation of daunorubicin hydrochloride (1) in aqueous DMF in the presence of NaHCO3 using N-β-glycoside N-bromoacetylglycyl derivatives, namely, α-l-Fucp-(1→2)-β-d-Galp-(1→4)-β-d-Glcp-NHCOCH2NHCOCH2Br (2a), α-l-Fucp-(1→4)-[β-d-Galp-(1→3)]-β-d-GlcpNAc-NHCOCH2NHCOCH2Br (3a), α-l-Fucp-(1→3)-β-d-GlcpNAc-NHCOCH2NHCOCH2Br (4a), and α-l-Fucp-(1→6)-β-d-GlcpNAc-NHCOCH2NHCOCH2Br (5a). The conjugates of daunorubicin were obtained as hydrochlorides (2b-5b) in 40% yield. Their oligosaccharide components are fragments of H type 5, Lea, Lex antigens and N-fucolglycan, respectively. 0(I) Erythrocytes hemagglutination inhibition assay was performed with conjugates 2b–5b and Ulex europaeus (UEA 1), Lotus tetragonolobus (LTA), and Laburnum anagyroides (LAA) plant fucolectins.

607. Scope and Predictive Genetic/Phenotypic Signatures of “Bicarbonate [NaHCO3]-Responsivity” and β-Lactam Sensitization among Methicillin-Resistant Staphylococcus aureus (MRSA)

BackgroundSelected MRSA strains become susceptible to β-lactams (e.g., oxacillin [OX]; cefazolin [CFZ]) in vitro when tested in a standard medium (cation-adjusted Mueller–Hinton Broth; CA-MHB) supplemented with NaHCO3 (“NaHCO3-responsivity”). In vivo activity of β-lactams was demonstrated for MRSA strains with this phenotype in a rabbit endocarditis model (Ersoy et al Antimicrob Agents Chemother 2019). The current study was designed to: (i) determine the prevalence of the NaHCO3-responsive phenotype in a large collection of clinical MRSA isolates; and (ii) identify genetic and phenotypic predictors of this phenotype. Methods. 58 recent MRSA bloodstream isolates representing contemporary clonal complex (CC) genotypes were screened for the NaHCO3-responsive phenotype by broth microdilution MICs in CA-MHB, with or without NaHCO3 supplementation (25–44 mM).Methods58 recent MRSA bloodstream isolates representing contemporary clonal complex (CC) genotypes were screened for the NaHCO3-responsive phenotype by broth microdilution MICs in CA-MHB, with or without NaHCO3 supplementation (25–44 mM).Results43/58 (74.1%) and 21/58 (36.2%) were rendered susceptible to CFZ and OX, respectively, in the presence of NaHCO3; 20 of the 21 OX-susceptible strains were also susceptible to CFZ in the presence of NaHCO3. High baseline β-lactam MICs (i.e., MICs in CA-MHB alone ≥64 µg/mL) was not predictive of NaHCO3 responsivity. The CC8 genotype was correlated with NaHCO3 responsivity for OX, but not CFZ (P < 0.05).ConclusionThe NaHCO3-responsive phenotype is relatively common for both OX and especially CFZ among clinical MRSA isolates. Identification of specific genetic factors linked to this phenotype remains ongoing. Confirmation in relevant animal models that this phenotype is predictive of β-lactam efficacy in vivo could provide a solid foundation for a paradigm shift in antimicrobial susceptibility testing of MRSA.Disclosures All authors: No reported disclosures.

Surface construction of nitrogen-doped chitosan-derived carbon nanosheets with hierarchically porous structure for enhanced sulfacetamide degradation via peroxymonosulfate activation: Maneuverable porosity and active sites

Nitrogen-doped chitosan-derived carbon nanosheets with hierarchically porous structure were synthesized via a facile pyrolysis treatment of chitosan/urea/NaHCO3 mixture (denoted as CNU). The contents of reactive functionalities, graphitization degree and porous structure of CNU can be effectively tailored by pyrolysis temperature (Tp). The outstanding peroxymonosulfate (PMS)-activation ability of CNU800 (prepared at Tp = 800 °C) for sulfacetamide (SAM) degradation related to its high level of C=O/C (23.7%) and graphitic N/C (4.8%), relatively high graphitization degree, and its large specific surface area and hierarchically porous structure. The introduction of urea in the presence of NaHCO3 during chitosan pyrolysis facilitated the formation of the graphene-like carbocatalyst with hierarchically porous structure and an enhanced PMS-activating activity. The effect of catalyst loading, PMS dosage and common matrix species on PMS activation by CNU800 for SAM degradation was investigated. Quenching experiment and electron paramagnetic resonance collectively revealed that non-radical oxidation (e.g., singlet oxygen (1O2)) was the dominant PMS-activating pathway in the CNU800/PMS/SAM system. The main SAM degradation pathway was also proposed. The conversion between N bonding configurations partially deactivated CNU800. This study deepens the understanding of biomass-based carbocatalyst for environmental remediation.

NaHCO3 Dilates Mouse Afferent Arteriole Via Na+/HCO3- Cotransporters NBCs.

Sodium bicarbonate has long been used to treat chronic kidney disease. It has been demonstrated to slow the decline in glomerular filtration rate in chronic kidney disease patient; however, the mechanisms are not completely understood. We hypothesized that NaHCO3 dilates afferent arterioles (Af-Art) by stimulating nitric oxide (NO) release mediated by the Na+/HCO3- cotransporter (NBC) contributing to the elevation in glomerular filtration rate. Isolated microperfused mouse renal Af-Art, preconstricted with norepinephrine (1 µmol/L), dilated 45±2% (n=6, P<0.05) in response to NaHCO3 (44 mmol/L). Whereas, NaCl solution containing the same Na+ concentration was not effective. The mRNA for NBCn1 and NBCe1 were detected in microdissected Af-Art using reverse transcription-polymerase chain reaction and quantitative polymerase chain reaction. The Af-Art intracellular pH measured with 2',7'-bis-(2-carboxyethyl)-5-(and-6) carboxyfluorescein, acetoxymethyl ester increased significantly by 0.29±0.02 (n=6; P<0.05) in the presence of NaHCO3, which was blunted by N-cyanosulphonamide compound (S0859) that is an inhibitor of the NBC family. After clamping the intracellular pH with 10 μM nigericin, changing the bath solution pH from 7.4 to 7.8 still dilates the Af-Art by 53±4% (n=7; P<0.005) and increases NO generation by 22±3% (n=7; P<0.005). Both pH-induced NO generation and vasodilation were blocked by L-NG-Nitroarginine Methyl Ester. NaHCO3 increased NO generation in Af-Art by 19±4% (n=5; P<0.005) and elevated glomerular filtration rate in conscious mice by 36% (233 versus 318 ul/min; n=9-10; P<0.0001). S0859 and L-NG-nitroarginine methyl ester blocked NaHCO3-induced increases in NO generation and vasodilation. We conclude that NBCn1 and NBCe1 are expressed in Af-Art and that NaHCO3 dilates Af-Art via NBCs mediated by NO that increases the glomerular filtration rate.

Appraisal of Ruthenium(II) complexes of (4-phenoxyphenylazo) ligands for the synthesis of primary amides by dint of hydroxylamine hydrochloride and aldehydes

A new family of O, N donor-functionalized (4-phenoxyphenylazo)-2-naphthol/4-substituted phenol-based ligands (HL1-HL4) has been synthesized. The prepared ligands were successfully utilized for the access of a series of ruthenium(II) carbonyl complexes of the type [Ru(L)Cl(CO)(EPh3)3] (E = phosphine/arsine), (L = 1-(4-phenoxyphenylazo)-2-naphthol (HL1), 2-(4-phenoxyphenylazo)-4-chlorophenol (HL2), 2-(4-phenoxyphenylazo)-4-methylphenol (HL3) and 2-(4-phenoxyphenylazo)-4-methoxyphenol (HL4)). All of the ruthenium(II) carbonyl complexes and ligands have been fully characterized by FT-IR, UV–visible, 1H NMR, 31P NMR, mass spectrometry and CHN analysis. The ligands have been analyzed by 13C NMR. The UV–visible spectroscopic study reveals that both the ligands and Ru(II) complexes exhibit excellent charge transfer transitions. This is the basic criteria for the oxidative amidation reaction, which is an influential strategy for the transformation of oxygenated organic compounds to the profitable amides. However, this catalytic process makes more impact on the application of new divalent ruthenium(II) azo compounds as catalyst in a single-pot conversion of aldehydes to amides in the presence of NaHCO3.

Functiaonalization of 2-(1-Cyclohexen-1-yl)aniline Derivatives

The reaction of 2-(1-cyclohexen-1-yl)aniline and -6-methylaniline with phthalic anhydride has afforded 2-(2-cyclohex-1-en-1-ylphenyl)- and 2-(2-cyclohex-1-en-1-ylphenyl)-6-methylphenyl)-1H-isoindole-1,3(2H)-diones. The reaction of the obtained isoindole-1,3-diones with bromine in dichloromethane in the presence of sodium bicarbonate has led to the formation of the product of pseudo-allylic halogenation. Replacement of the halogen atom by methoxy group has been performed by keeping 2-[2-(6-bromocyclohex-1-en-1-ylphenyl)-6-methylphenyl)]-1H-isoindole-1,3(2H)-dione in a methanolic solution in the presence of NaHCO3. The reaction of 2-(2-cyclohex-1-en-1-yl-6-methylphenyl)-1H-isoindole-1,3(2H)-dione with molecular bromine in the presence of methanol has given a co-halogenation product, whereas the dibromination product has been obtained in the presence of octyl alcohol.

4,6‐Diacetyl Resorcinol Based Vanadium(V) Complexes: Reactivity and Catalytic Applications

Four ONO donor ligands are isolated from the condensation of 4,6‐diacetyl resorcinol with isonicotinoyl hydrazide (H2dar‐inh, I), nicotinoyl hydrazide (H2dar‐nah, II), benzoyl hydrazide (H2dar‐bhz, III), and 2‐furoyl hydrazide (H2dar‐fah, IV) on refluxing in MeOH. The reaction of in situ generated aqueous K[H2VVO4] with ligands I–IV at neutral pH gives complexes [K(H2O)2][VO2(dar‐inh)] (1), [K(H2O)2][VO2(dar‐nah)] (2), [K(H2O)2][VO2(dar‐bhz)] (3), and [K(H2O)2][VO2(dar‐fah)] (4), respectively. The reaction of [VIVO(acac)2] (acac = acetylacetonato) with these ligands (I–IV) under aerobic conditions in methanol yields oxidomethoxidovanadium(V) complexes [VO(OMe)(MeOH)(dar‐inh)] (5), [VO(OMe)(MeOH)(dar‐nah)] (6), [VO(OMe)(MeOH)(dar‐bhz)] (7), and [VO(OMe)(MeOH)(dar‐fah)] (8). All the isolated complexes are characterized by elemental, thermal, electrochemical, and spectroscopic techniques [FTIR, UV/Vis, NMR (1H, 13C and 51 V NMR)], and single‐crystal X‐ray diffraction analysis (for 1, 6, 7, and 8). X‐ray analysis confirms the coordination of the ligands through Ophenolate, Nazomethine, and Oenolate to the metal center. In the molecular structure of [K(H2O)(EtOH)][VVO2(dar‐inh)] (abbreviated as 1a where one molecule of water is replaced by EtOH), water molecules act as bridges between two K+ ions and the complex shows a dimeric structure due to the presence of electrostatic interactions between V=O oxygen atoms with K+ ions. These complexes are active catalysts for the oxidative bromination of thymol in the presence of KBr, HClO4, and H2O2 and give 2‐bromothymol, 4‐bromothymol, and 2,4‐dibromothymol as major products. Complexes 1–4 were also tested as catalysts for the epoxidation of various alkenes (namely styrene, cyclohexene, cis‐cyclooctene, 1‐hexene, 1‐octene, cyclohexenone, and trans‐stilbene) with H2O2 in the presence of NaHCO3 as promoter, giving the corresponding epoxides selectively.

Copper-Catalyzed Synthesis of 13-Aminoisoquinolino[2,1-a ]perimidine-12-carboxylates via α-Arylation with a High Chemoselectivity

The α-arylation between cyanoacetate and 2-(2-bromophenyl)-1H-perimidine took place first catalyzed by CuI/L-proline in the presence of NaHCO3, and then the amino on perimidine chemoselectively attacked the cyano group to undergo a nucleophilic addition, giving a series of 13-aminoisoquinolino[2,1-a]perimidine-12-carboxylate derivatives in good yields.

N-substituted piperazinyl sarafloxacin derivatives: synthesis and in vitro antibacterial evaluation

BackgroundFluoroquinolones (FQs) are compounds of major interest with broad antimicrobial activities against community and hospital-acquired infections such as respiratory tract infections (nosocomial pneumonia, chronic bronchitis and tuberculosis), skin and soft tissue infections, bone and joint infections, intra-abdominal infections and sexually transmitted diseases. This broad range of activities along with favorable pharmacokinetic and low toxicity introduced this class of compounds as important antimicrobial chemotherapy agents. The rapid increase in prevalence of FQs resistant microbes in environment motivated medicinal chemists to discover new quinolone-based compounds with potent activities against Gram-positive bacteria.MethodsThe designed compounds were prepared through the two-component reaction between aromatic α-haloketones or α-halooximes and sarafloxacin in the presence of NaHCO3 in DMF, affording the corresponding N-[2-(aryl-3-yl) ethyl] piperazinyl quinolone derivatives in good yields. All synthesized compounds were evaluated for antibacterial activities against Gram-positive [Staphylococcus aureus ATCC 6538p, Micrococcus luteus, ATCC 1110, Staphylococcus epidermidis ATCC 12228 and Bacillus subtilis ATCC 6633] and Gram-negative [Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 10031 Pseudomonas aeruginosa ATCC 9027 and Serratia marcescens PTCC 1111] bacteria.ResultsThe antibacterial activities of 24 new compounds were reported as MIC values in comparison to sarafloxacin. The most active compound, 4 g, exhibited similar inhibitory activity against Gram-positive bacteria including S. aureus, S. epidermidis and B. subtilis compared to positive control. Furthermore, benzyloxime incorporated derivatives (4 s-4x) showed poor activity against all tested strains, except 4x.ConclusionThe obtained results indicated that the synthesized compounds containing substituted piperazine moiety at the C-7 position displayed same or weak inhibitory activities compared to sarafloxacin. Graphical abstractᅟ

Prototyping flexible supercapacitors produced with biohydrogel

Flexible symmetric supercapacitor prototypes composed of electrodes that were prepared by polymerizing poly(hydroxymethyl-3,4-ethylenedioxythiophene) inside a poly-γ-glutamic acid (γPGA) biohydrogel matrix, previously loaded with microparticles of poly(3,4-ethylenedioxythiophene) (PEDOT) and alumina (Al2O3), have been fabricated and characterized. Prototypes have been assembled in a totally solid, compact and lightweight configuration, where the supporting electrolytic medium is a γPGA hydrogel prepared in presence of NaHCO3. The elements of the prototypes have been characterized and their optimized to obtain the highest specific capacitance. The electrochemical performances of the prototypes have been investigated by cyclic voltammetry, charge-discharge galvanostatic cycles and electrochemical impedance spectroscopy. After 2000 charge-discharge cycles (i.e. 60.000 s of continuous operation), the loss of specific capacitance is of only 8%, revealing an excellent stability. Results are very promising for the development of compact, flexible, lightweight and biocompatible supercapacitors to be employed like energy-autonomous electronic devices.

Tunable Synthesis of Hierarchical Superparamagnetic Fe3O4 Nanospheres by a Surfactant-Free Solvothermal Method

Hierarchical Fe3O4 nanospheres with superparamagnetism have been fabricated via a solvothermal method without any surfactants. The effect of reaction parameters like the types of the reagent, the reaction time, and the reagent concentration on the morphology and structure of the resultant samples are investigated. In this method, ferric chloride (FeCl3 ⋅ 6H2O) is used as the iron source, and EG acts as both solvent and reducing agent. The presence of NaHCO3 or Na2CO3 provides alkine condition and gaseous bubbles in the control over the size of Fe3O4 nanospheres. The formation mechanism for Fe3O4 nanospheres is illustrated by an Ostwald ripening process. The Fe3O4 nanospheres were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and superconducting quantum interference device magnetometer (SQUID-VSM). The Fe3O4 nanospheres exhibited a wider size distribution at the amount of 0.397 mol/L NaHCO3, showing a high saturation magnetization close to 84.46 emu/g. The Fe3O4 nanospheres soluble in deionized water is also investigated.

Metal-free and selective cleavage of unstrained carbon–carbon single bonds: Synthesis of β-ketosulfones from β-chlorohydrins and sodium sulfinates

ABSTRACTA metal-free protocol for the selective cleavage of unstrained C–C single bonds was developed. Under the catalysis of KI and in the presence of NaHCO3, the readily available α-chloro-β-hydroxy ketones underwent bond breaking and sulfonylation smoothly to afford β-ketosulfones with high efficiency and broad substrate scope. Mechanism investigations, both experimental and theoretical, showed that a retro-aldol cleavage/nucleophilic substitution sequence might be involved.

Acetonylation of 5(3)-(1H-tetrazol-1-yl)-3(5)-nitro-1H-pyrazole

N-Acetonylation of 5(3)-(1H-tetrazol-1-yl)-3(5)-nitro-1H-pyrazole with bromoacetone in the presence of NaHCO3 at 60 °C gave, along with expected isomeric N-acetonyl derivatives, a tricyclic product of the intramolecular electrophilic attack at the carbon atom of the tetrazole cycle.

Characterization of carbon dioxide concentrating chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel

Proteomics and metabolomics analysis has become a powerful tool for characterization of microbial ability for fixation of Carbon dioxide. Bacterial community of palaeoproterozoic metasediments was enriched in the shake flask culture in the presence of NaHCO3. One of the isolate showed resistance to NaHCO3 (100mM) and was identified as Serratia sp. ISTD04 by 16S rRNA sequence analysis. Carbon dioxide fixing ability of the bacterium was established by carbonic anhydrase enzyme assay along with proteomic analysis by LC–MS/MS. In proteomic analysis 96 proteins were identified out of these 6 protein involved in carbon dioxide fixation, 11 in fatty acid metabolism, indicating the carbon dioxide fixing potency of bacterium along with production of biofuel. GC–MS analysis revealed that hydrocarbons and FAMEs produced by bacteria within the range of C13–C24 and C11–C19 respectively. Presence of 59% saturated and 41% unsaturated organic compounds, make it a better fuel composition.