Presence Of NaHCO3 Research Articles

Effect of calmodulin on the stimulation of capacitation and acrosome reaction of frozen thawed bull spermatozoa

Capacitation and acrosome reaction (AR) are the prerequisites for successful fertilization by mammalian spermatozoa. Intracellular calcium (Ca2+) has a regulatory role in sperm motility, capacitation, and AR. Calmodulin (CaM) antagonists calmidazolium (CZ) and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W7) were used to investigate the possible role of CaM, a Ca2+ specific binding protein, on motility, capacitation and AR of frozen-thawed bovine spermatozoa. Capacitation and AR in sperm were evaluated by using chlortetracycline (CTC) staining technique. Addition of the 1 mM dibutyryl cAMP (dbcAMP) and 100 ?M 1-methy l-3-isobutylxanthine (IBMX) to CaM antagonists treated sperm incubated in the presence of NaHCO3 and CaCl2 in media overcome the inhibitory effects of these antagonists to support capacitation and AR at 4 h of incubation period. In contrast, addition of dbcAMP with IBMX induced AR in spermatozoa incubated with NaHCO3-free medium but these compounds did not induce AR in cells incubated in CaCl2-free medium. However, the addition of dbcAMP and IBMX partially, but significantly (p<0.01) reversed the inhibitory effect of W7 and CZ on the sperm capacitation and AR. These results suggest that CaM may play an important role in the regulation of capacitation and AR in frozen-thawed bovine spermatozoa.Bang. J. Anim. Sci. 2016. 45 (3): 1-9

Succinate and Lactate Production from Euglena gracilis during Dark, Anaerobic Conditions.

Euglena gracilis is a eukaryotic, unicellular phytoflagellate that has been widely studied in basic science and applied science. Under dark, anaerobic conditions, the cells of E. gracilis produce a wax ester that can be converted into biofuel. Here, we demonstrate that under dark, anaerobic conditions, E. gracilis excretes organic acids, such as succinate and lactate, which are bulk chemicals used in the production of bioplastics. The levels of succinate were altered by changes in the medium and temperature during dark, anaerobic incubation. Succinate production was enhanced when cells were incubated in CM medium in the presence of NaHCO3. Excretion of lactate was minimal in the absence of external carbon sources, but lactate was produced in the presence of glucose during dark, anaerobic incubation. E. gracilis predominantly produced L-lactate; however, the percentage of D-lactate increased to 28.4% in CM medium at 30°C. Finally, we used a commercial strain of E. gracilis for succinate production and found that nitrogen-starved cells, incubated under dark, anaerobic conditions, produced 869.6 mg/L succinate over a 3-day incubation period, which was 70-fold higher than the amount produced by nitrogen-replete cells. This is the first study to demonstrate organic acid excretion by E. gracilis cells and to reveal novel aspects of primary carbon metabolism in this organism.

Cation-Dependent Self-assembly of Vanadium Polyoxoniobates.

Reaction of Na7H[Nb6O19]·15H2O with NaVO3·2H2O at 220 °C in the presence of NaHCO3 gives new bicapped α-Keggin vanadododecaniobate [VNb12O40{NbO(CO3)}2]13-, isolated and structurally characterized as Na9H4[VNb12O40{NbO(CO3)}2]·37H2O (1). According to 51V NMR and ESI-MS data, this anion equilibrates in solution with [VNb12O40]15- and oligomeric species that result from dissociation of the {NbO(CO3)}+ fragments. In the presence of potassium, the same reaction gives [VxNb24O76]n- (x = 4, n = 12 (2a); x = 3, n = 17 (2b)). The anions with x = 3 and 4 cocrystallize together, but exist as separate entities both in solid and in solution according to 51V MAS NMR and ESI-MS data.

ChemInform Abstract: One‐Step Synthesis of Imidazo[1,2‐a]pyridines in Water.

A novel straightforward method for the synthesis of 2,3-disubstituted imidazo[1,2-a]pyridine derivatives in water as a truly safe and cheap reaction medium was developed. Hence, N-alkyl pyridinium and S-alkyl thiouronium salts were reacted in the presence of NaHCO3 as a mild base in water to produce imidazo[1,2-a]pyridines in moderate to excellent yields.

Tentacle-type immobilized metal affinity cryogel for invertase purification from Saccharomyces cerevisiae

The aim of this study is to investigate the usability of cryogel columns for the purification of invertase from Saccharomyces cerevisiae. Poly(2-hydroxyethyl methacrylate) monolithic columns were produced via cryogelation. Ester groups of the poly(2-hydroxyethyl methacrylate) structure were then converted to imine groups by the reaction with poly(ethylene imine) in the presence of NaHCO3. Transition metal ions, Cu(II), Co(II), and Ni(II), were chelated on the PEI-modified cryogel columns. Purification of invertase from natural source namely S. cerevisiae was also studied, and the purification fold values were obtained as 41.350, 44.714, and 30.302 for Cu(II)-chelated, Co(II)-chelated, and Ni(II)-chelated PHEMA/PEI columns, respectively.

Chlorination and decarboxylation of (heptafluoronaphthalen-2-yl)acetic acid. Synthesis of 2-(dichloromethyl)- and 2-(difluoromethyl)heptafluoronaphthalenes

Decarboxylation of (heptafluoronaphthalen-2-yl)acetic acid in DMF in the presence of NaHCO3 gave 2-methylheptafluoronaphthalene, and treatment with PCl5 on heating afforded dichloro(heptafluoronaphthalen-2-yl)acetic acid. Decarboxylation of the latter in DMF led to the formation of 2-(dichloromethyl)-heptafluoronaphthalene which was converted to 2-(difluoromethyl)heptafluoronaphthalene by heating with cesium fluoride.

A Highly Efficient and Reusable Palladium(II)/Cationic 2,2'-Bipyridyl-Catalyzed Stille Coupling in Water.

A water-soluble PdCl2(NH3)2/cationic 2,2′-bipyridyl system was found to be a highly efficient catalyst for Stille coupling of aryl iodides and bromides with organostannanes. The coupling reaction was conducted at 110 °C in water, under aerobic conditions, in the presence of NaHCO3 as a base to afford corresponding Stille coupling products in good to high yields. When aryltributylstannanes were employed, the reactions proceeded smoothly under a very low catalyst loading (as little as 0.0001 mol %). After simple extraction, the residual aqueous phase could be reused in subsequent runs, making this Stille coupling economical. In the case of tetramethylstannane, however, a greater catalyst loading (1 mol %) and the use of tetraethylammonium iodide as a phase-transfer agent were required in order to obtain satisfactory yields.

Salts of 2- or 3-haloalkylamines in the synthesis of N-aminoalkyl derivatives of heterocyclic and aromatic amines

Reactions of 2-haloethyl- or 3-halopropylamine salts with NH-substrates (indoline, 1,2,3,4-tetrahydroquinoline, aniline, and N-ethylaniline) in the presence of NaHCO3 in water furnished various N-aminoalkyl derivatives of heterocyclic and aromatic amines.

Oxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) chalcogenides and use of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl)sulfone in heterocyclization with primary amines

AbstractOxidation of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfide and selenide with hydrogen peroxide in chloroform/acetic acid or acetic acid affords previously unknown E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfoxide, selenoxide, and sulfone. The reaction of E,E‐bis(3‐bromo‐1‐chloro‐1‐propen‐2‐yl) sulfone with primary amines in ethanol in the presence of NaHCO3 or Na2CO3 is found to lead not only to heterocyclization but also to alcoholysis of the chloromethylidene groups in the intermediate bis(chloromethylidene) derivatives of thiomorpholine‐1,1‐dioxides to afford N‐organyl‐2(E),6(E)‐bis(ethoxymethylidene) thiomorpholine‐1,1‐dioxides as final products.

Smooth Photocatalyzed Benzylation of Electrophilic Olefins via Decarboxylation of Arylacetic Acids.

Arylacetic acids were used as sources of benzyl radicals under tetrabutylammonium decatungstate photocatalyzed conditions for the benzylation of electron-poor olefins. The reaction proceeds smoothly in a mixed aqueous medium (MeCN/H2O 2/1) in the presence of NaHCO3, NaClO4, and an electron transfer agent (biphenyl). The reaction tolerates a wide variety of functional groups on the aromatic ring (whether electron donating or electron withdrawing) and can be extended to heteroaromatic analogues. The olefins have the double role of radical trap and electron acceptor. The present approach can also be extended to arylpropionic acids (including the nonsteroidal anti-inflammatory drugs ibuprofen and flurbiprofen), as well as mandelic acid derivatives.

Dithiocarbamate as an efficient intermediate for the synthesis of 2-(alkylthio)thiazol-4(5H)-ones

ABSTRACT An effective approach for the synthesis of 2-(alkylthio)thiazol-4(5H)-ones from alkyl dithiocarbamates and chloroacetyl chloride in the presence of NaHCO3 has been developed. Good to excellent yields of products, simple reaction conditions and general applicability are the most important advantages of this protocol.

Crystal structure, computational studies, and stereoselectivity in the synthesis of 2-aryl-thiazolidine-4-carboxylic acids via in situ imine intermediate

ABSTRACTThis article presents the synthesis of (2R/2S,4R)-2-aryl-thiazolidine-4-carboxylic acids via nucleophilic addition of L-Cysteine on aromatic aldehydes involving a yield and time-effective room temperature reaction in an aqueous DMSO medium in the presence of NaHCO3 as a base. The synthesized diastereomers were spectroscopically characterized and quantified for diastereomeric excess by liquid chromatography-mass spectrometry analysis. The impact of the type and position of substituent in aromatic aldehydes on reaction time, % yield, 1H NMR shift at newly formed chiral center [C(2)-H], and diastereomeric excess (de%) have been investigated. A plausible mechanism for stereoselectivity via an in situ imine intermediate is proposed using real-time IR monitoring of the synthetic reaction based on the significant signals at 1597, 1593 cm−1 for imine (C=N) stretching. The imine mechanism for stereoselectivity was further supported by NMR studies of azomethine 13C NMR signals at 159, 160 δ ppm and by the single crystal structure of hitherto unknown (2S,4R)-3-(tert-butoxycarbonyl)-2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid (3a) obtained as a major diastereomer in the synthesis of the butyloxy carbonyl (BOC) derivative of (2R/2S,4R)-2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid. The significant ortho-OH effect of phenolic hydroxyl group leading to strong hydrogen bondings plays a vital role in the formation of 2S,4R BOC derivative stereoselectively. The frontier molecular orbitals, possible electronic excitations, IR band characterizations, and reactivity parameters of newly reported compound (3a) have been predicted using quantum chemical descriptors from density functional theory. The theoretical exploration of experimental spectra using time-dependent DFT indicated a (π–π*) transition between HOMO and LUMO in the ultraviolet region.

Assessment of ground water qualities of some areas of Imphal west district of Manipur during Pre-Monsoon – 4th Phase

Fifteen ground water samples (S-1 to S-15) were collected from 12 hand pumps and 3 dug wells of Imphal West district of Manipur during pre-monsoon period(May) of 2015. They were analyzed for physicochemical parameters such as temperature, p H , TDS (total dissolved solids), electrical conductivity (EC), total alkalinity (TA) (and hence CO 2- 3 and HCO - 3 ), total hardness (TH), Ca 2+ , Mg 2+ , Na + , K + and Cl - . Ground waters represented by S-1,S-2,S-10,S-11 and S-13 to S-15 are found to be fit for drinking purpose from physicochemical analysis point of view. But TDS values for S-3 and S-4, total alkalinity values for S-3 to S-9 andS-12, total harness value for S-8, concentration of Mg 2+ for S-8, and concentrations of Na + for S-3 and S-4 are above their corresponding acceptable limits but below the permissible limits of BIS standard for drinking water and threshold limit of WHO (in case of Na + ). So, some suitable treatments are necessary so as to keep the values/concentrations of the above mentioned parameters below their corresponding acceptable limits/threshold limit of BIS standard for drinking water and that of WHO. However, ground waters represented by S-3 to S-9 and S-12 are fit for drinking in absence of alternate sources. All the ground waters (S-1 to S-15) are fit for other domestic and irrigation purposes. Further correlation coefficient data reveals that TA shows strong positive correlations with HCO 3 - , Na + and Mg 2+ (r= 1, 0.892 and 0.649 respectively) but moderately strong positive correlation with Ca 2+ (r=0.541) showing that the total alkalinity of such ground waters is due to the presence of NaHCO 3 , CaHCO 3 and MgHCO 3 . Strong positive correlations of TH (total hardness) with Ca 2+ , Mg 2+ and HCO 3 - (r = 0.944, 0.970 and 0.629 respectively) show that total hardness for these different ground waters, is due to the presence of CaHCO 3 and MgHCO 3 .

Benzo[4,5]imidazo[2,1-b]quinazolin-12-ones and benzo[4,5]imidazo[1,2-a]pyrido[2,3-d]pyrimidin-5-ones by a sequential N-acylation–SNAr reaction

An efficient synthesis of benzo[4.5]imidazo[2,1-b]quinazolin-12-ones and benzo[4,5]imidazo[1,2-a]pyrido[2,3-d]pyrimidin-5-ones is reported from the reaction of 2-aminobenzimidazole with 2-haloaroyl chlorides. The reaction takes advantage of the 1,3-disposition of nucleophilic centers in 2-aminobenzimidazole and the similar arrangement of electrophilic sites in the acid chloride to assemble the central six-membered ring. Initial treatment of 2-aminobenzimidazole (1.2equiv) with the acid chloride (1equiv) in the presence of NaHCO3 (2equiv) in DMF at −10°C gives acylation at the saturated benzimidazole nitrogen. Subsequent heating to 75°C, in the same reaction vessel, then completes the synthesis via an SNAr ring closure by the C2 amino group. The reaction has broad scope, and gives 76–98% yields for the two-step sequence. The final products exist in a tautomeric equilibrium, which can be blocked by acylation at N6.

Palladacycles Based on 8-Aminoquinoline Carboxamides of Cobalt and Iron Sandwich Compounds and a New Method to α-Alkylate Cp Rings of Metal Sandwich Carboxamides

Reactions of {η5-C5H4[C(O)Cl]}Co(η4-C4Ph4) and {η5-C5H4[C(O)Cl]}Fe(η5-Cp) with 8-aminoquinoline resulted in cobalt and iron sandwich derived carboxamides. The reaction of these carboxamides with Pd(OAc)2 in acetonitrile resulted in αC–H activation of the Cp rings of the sandwich compounds and formation of novel palladacycles 3 and 4, having both N–H and one α-C–H hydrogen atom of the Cp ring displaced and palladium forming a square planar complex with acetonitrile as the fourth ligand. These air-stable palladacycles reacted with MeI and EtI in acetic acid, resulting in mono- and 2,5-di-α-alkylated sandwich carboxamides, thereby providing a new method to realize Cp-multisubstituted sandwich compounds. Selectivity in α-substitution was observed in the presence of NaHCO3. The cobalt sandwich carboxamide 1, the new palladacycles 3 and 4, and the 2,5-dimethylated cobalt sandwich carboxamide 5 have also been structurally characterized using single-crystal X-ray structural studies.

Novel N-2-(Furyl)-2-(chlorobenzyloxyimino) Ethyl Piperazinyl Quinolones: Synthesis, Cytotoxic Evaluation and Structure-Activity Relationship.

Quinolone antibacterials are one of the most important classes of pharmacological agents known as potent inhibitors of bacterial DNA gyrase and topoisomerase IV that efficiently inhibit DNA replication and transcription by generating several double-stranded DNA break. Some quinolone derivatives demonstrated inhibitory potential against eukaryote topoismarase II and substantial dose-dependent cytotoxic potential against some cancerous cells. In present study, synthesis and cytotoxic activity evaluation of new series of N-pipearzinyl quinolones containing N-2-(furyl-2 or 3-yl)-2-(chlorobenzyloxyimino) ethyl moiety 7a-i have been studied. Reaction of quinolone, with 2-bromo-1-(furan-2 or 3-yl)ethanone-O-substituted chlorobenzyloxime in DMF in presence of NaHCO3 at room temperature, gave the title compounds N-2-(furan-2 or 3-yl)-2-(chlorobenzyloxyiminoethyl) quinolone 7a-i. Synthesized compounds were further evaluated in-vitro against three human breast tumor cell lines. Preliminary screening indicated that compound 7 g demonstrated significant growth inhibitory potential against all evaluated cell lines. The results of structure-activity relationship study exhibited that quinolone derivatives are superior in cytotoxic potential compared to 1, 8-naphthyridone series. Furthermore, ethyl quinolone derivatives were more potent cytotoxic agents comparing with cyclopropyl quinolones.

Solvolysis of 14,17-etheno-bridged 16α-nitroestratrienyl acetate and lactam formation pathways studied by LC–NMR and LC–MS. Structures of minor products

The ethanol solvolysis of 3-methoxy-14,17-etheno-16α-nitroestra-1,3,5(10)-trien-17β-yl acetate in the presence of NaHCO3 was studied by means of real-time NMR experiments, LC–SPE–NMR, and LC–MS. The pathway to form 3-methoxy-2′-oxopyrrolidino-[4′,5′:14β,15β]-estra-1,3,5(10)-trien-17-one was disclosed. The intermediacy of nitrile oxide and alkoxynitrone was postulated based on the analysis of the reaction products. The proposed mechanism of cleaving the bridge in the nitro compound is legal for the formation of N-acetoxylactams, nitriles, isoxazoles and isoxazolines.

Synthesis of icariin from kaempferol through regioselective methylation and para-Claisen-Cope rearrangement.

The hemisynthesis of the naturally occurring bioactive flavonoid glycoside icariin (1) has been accomplished in eleven steps with 7% overall yield from kaempferol. The 4′-OH methylation of kaempferol, the 8-prenylation of 3-O-methoxymethyl-4′-O-methyl-5-O-prenyl-7-O-benzylkaempferol (8) via para-Claisen–Cope rearrangement catalyzed by Eu(fod)3 in the presence of NaHCO3, and the glycosylation of icaritin (3) are the key steps.

Sodium bicarbonate assisted oxidation, by H2O2, of styrene and cyclohexene using polymer grafted dioxidomolybdenum(VI) complex as a catalyst

Ligand H2hap-iah (I), obtained by the condensation of equimolar amounts of o-hydroxy acetophenone (hap) and indole-3-acetic hydrazide (iah) reacts with [MoVIO2(acac)2] in 1:1 ratio in refluxing methanol to give [MoVIO2(hap-iah)(MeOH)] (1). Complex 1 has been grafted in chloromethylated polystyrene cross-linked with 5% divinylbenzene {now abbreviated as PS-[MoVIO2(hap-iah)(MeOH)] (2)} via covalent bonding through imino nitrogen of the indole group. Both complexes are characterized by various spectroscopic techniques (IR, electronic, 1H, and 13C NMR), analytical and thermal studies. Complex 2 has also been analyzed by atomic force microscopy (AFM), field-emission scanning electron micrographs (FE-SEM) as well as energy dispersive X-ray (EDAX) studies. The polymer-grafted compound 2 was used for the catalytic oxidation of styrene and cyclohexene in the presence of NaHCO3 using aqueous H2O2 as oxidant. The intermediate peroxido species, expected to be involved during catalytic action, was also generated from the solution of 1 and studied by UV–vis. Various reaction conditions were considered to optimize reactions conditions for the maximum oxidation of substrates. Styrene under optimized reaction conditions gave mainly styrene oxide as a major product. Oxidation of cyclohexene gave cyclohexene oxide selectively. The polymer-grafted complex shows higher conversions than its neat counterpart. The polymer-grafted complex provides additional advantage over its homogeneous counterpart in terms of increased catalyst lifetime and easier separation from the reaction mixture and allows for recyclable catalytic system.

Hydrogen production by water splitting with Al and in-situ reduction of CO2 into formic acid

The utilization of CO2 as a carbon source to produce useful chemicals could be regarded as a promising way to reduce CO2 emissions and to minimize global warming. In this study, hydrogen obtained by water spilling with Al was used for in-situ reduction of CO2 into formic acid. The common bulk Al was employed as a reducing agent to split water for reduction of CO2, possessing safe and convenient advantages. Results revealed that the hydrogen production from water with the oxidation of Al can be enhanced in the presence of NaHCO3, as a source of CO2, which can be in-situ reduced into formic acid. A considerable high formic acid yield of 64% with near 100% selectivity was achieved. Additionally, experiments of mix-metals containing Fe, Al, Cu. Zn and Sn with NaHCO3 were conducted to investigate the Electronic waste (E-waste) as reductant for reducing CO2 and more than 60% yield of formic acid were obtained, indicating that CO2 reduction by waste metal is feasible. This study can assist in developing an efficient and economical process for conversion of CO2 to value-added chemicals.