- Discovery of Unprecedented Hydrazine-Forming Machinery in Bacteria
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Recent studies described several different routes that facilitate nitrogen-nitrogen bond formation in natural product biosynthesis. We report herein the identification of unprecedented machinery for hydrazine formation involved in the biosynthesis of s56-p1, a dipeptide natural product with a unique hydrazone unit. The gene cassette comprising this machinery is widespread across several bacterial phyla, highlighting the overlooked potential of bacteria to synthesize hydrazine.
- Matsuda, Kenichi,Tomita, Takeo,Shin-Ya, Kazuo,Wakimoto, Toshiyuki,Kuzuyama, Tomohisa,Nishiyama, Makoto
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- Azine based AIEgens with multi-stimuli response towards picric acid
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Multifunctional aggregation induced emission luminogens (AIEgens) are novel materials which have significant applications in various fields including biomedical, optoelectronics and sensors. Enormous efforts have been directed towards the strategic development and characterisation of AIEgens, in order to better understand the AIE mechanism. Herein, we studied the photophysical properties of symmetrical azine (D-π-D) based AIEgens in detail by varying the solvent polarity and viscosity. The AIE behaviour of the azine derivatives relies on the substituents on the nitrogen atom of the amine moiety. Further, these azine derivatives sense the picric acid (PA) with high selectivity and sensitivity in both monomer and aggregated forms. The hydrogen bonding interaction of PA with any one side of the amine nitrogen leads to the formation of a new intramolecular charge transfer state which results in the formation of new absorption and emission spectra. Interestingly in the presence of PA, azine monomers exhibit fluorescence enhancement in pure THF, while aggregated azine molecules show fluorescence quenching in THF-water mixtures.
- Pavithra, Kumaravelu,Sathiyaraj, Munusamy,Thiagarajan, Viruthachalam
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- Tuning of azine derivatives for selective recognition of Ag+ with the in vitro tracking of endophytic bacteria in rice root tissue
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Several azine derivatives have been prepared and structurally characterized by spectroscopic and single-crystal X-ray diffraction analysis. Two of them, viz. naphthalene based (A10) and anthracene based (A11) show fluorescence enhancement in the presence of Ag+ in aqueous-methanol. Moreover, A11 efficiently tracks Ag+in vitro endophytic bacteria infected rice root tissue. Experimental results have been substantiated by theoretical DFT calculations.
- Ghosh, Abhijit,Adhikari, Sangita,Ta, Sabyasachi,Banik, Avishek,Dangar, Tushar Kanti,Mukhopadhyay, Subhra Kanti,Matalobos, Jesús Sanmartín,Brand?o, Paula,Félix, Vítor,Das, Debasis
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- Conversion of Ammonia to Hydrazine Induced by High-Frequency Ultrasound
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Hydrazine is a chemical of utmost importance in our society, either for organic synthesis or energy use. The direct conversion of NH3 to hydrazine is highly appealing, but it remains a very difficult task because the degradation of hydrazine is thermodynamically more feasible than the cleavage of the N?H bond of NH3. As a result, any catalyst capable of activating NH3 will thus unavoidably decompose N2H4. Here we show that cavitation bubbles, created by ultrasonic irradiation of aqueous NH3 at a high frequency, act as microreactors to activate and convert NH3 to NH species, without assistance of any catalyst, yielding hydrazine at the bubble–liquid interface. The compartmentation of in-situ-produced hydrazine in the bulk solution, which is maintained close to 30 °C, advantageously prevents its thermal degradation, a recurrent problem faced by previous technologies. This work also points towards a path to scavenge .OH radicals by adjusting the NH3 concentration.
- Allavena, Audrey,Amaniampong, Prince N.,Chave, Tony,De Oliveira Vigier, Karine,Grimaud, Laurie,Humblot, Anaelle,Jér?me, Fran?ois,Streiff, Stéphane
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supporting information
p. 25230 - 25234
(2021/09/14)
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- Dihydrazone compound high in affinity with Abeta protein and Tau protein, derivative thereof, and applications of dihydrazone compound and derivative
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The invention provides a dihydrazone compound high in affinity with Abeta protein and Tau protein, a derivative thereof, and applications of the dihydrazone compound and the derivative. The structureof the dihydrazone compound is represented by formula I. The dihydrazone compound can be directly taken as a fluorescence probe used for detecting neurofibrillary tangles in vivo or in tissue samples;when the dihydrazone compound is adopted in nuclear medicine imaging, appropriate radioisotopes are needed for labeling. The dihydrazone compound is especially suitable to be used for diagnosis of neurodegenerative diseases, and diagnosis of patients with diseases with Abeta plaques including Alzheimer's disease.
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Paragraph 0029-0031; 0050-0052
(2019/05/15)
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- C[sbnd]N bond formation in alicyclic and heterocyclic compounds by amine-modified nanoclay
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In the current protocol, amine functionalized montmorillonite K10 nanoclay (NH2-MMT) was applied to catalyze the formation of C[sbnd]N bonds in the synthesis of azines and 2-aminothiazoles at room temperature. In comparison with the current methods of C[sbnd]N bond formation, this approach displays specific advantages include atom economy, clean conversion, design for energy efficiency, the use of nontoxic and heterogeneous catalyst, higher purity and yields, safer solvent and reagents for this organic transformation.
- Zarnegar, Zohre,Alizadeh, Roghayeh,Ahmadzadeh, Majid,Safari, Javad
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- Compound capable of detecting organophosphate neurotoxic agent stimulants and application thereof
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The invention relates to a compound capable of detecting an organophosphate neurotoxic agent stimulants and application thereof. The compound has a structural general formula shown as the specification, can be used for detection of organophosphate neurotoxic agent stimulants according to the change of color or fluorescence in preparation of solutions, films or test paper. The compound provided by the invention has the advantages of simple preparation method, high yield, easy separation, high purity, and sensitive response to organophosphorus neurotoxic agents, and can achieve quick and accurate detection of organophosphorus neurotoxic agent stimulants in solutions or gas phases.
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Paragraph 0033; 0039; 0040; 0041; 0042; 0043
(2017/03/08)
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- Tungsten hexachloride nanoparticles loaded on montmorillonite K-10: a novel solid acid catalyst in the synthesis of symmetrical and unsymmetrical azines
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In the present investigation, we have developed a novel technique to prepare azines using nano-WCl6 loaded on Montmorillonite K10 clay as a highly active catalyst. A variety of aldehydes and ketones were efficiently converted to the corresponding azines using catalytic amounts of nanosized WCl6/Mont. K10 under mild conditions. The nanostructures of WCl6 loaded on Mont. K10 as solid acid catalyst have been prepared by solid dispersion method. The advantages of this catalyst are rapid completion of the reactions, simplicity of performance, lack of pollution and mild and green reaction conditions. The morphologies, structure, and chemical components of parent and modified clay were successfully characterized using SEM, FT-IR, CV, XRD and EDX measurements.
- Safari, Javad,Gandomi-Ravandi, Soheila,Shariat, Saeedeh
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p. 1499 - 1507
(2016/07/06)
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- Anomalous reaction of hydrazine hydrate with 5-arylidene barbiturates: Formation of benzalazines
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Reaction of 5-arylidene barbiturates (3a-i) with hydrazine hydrate resulted in the unusual formation of novel benzalazines (5a-i) in 70-90% yield rather than the expected pyrazole fused pyrimidines.
- Goudgaon,Upendar Reddy, Ch.,Patil, Sharanabasappa,Sheshikant
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p. 277 - 282
(2019/01/21)
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- Features of the reactions of β-Aryl(heteryl)-α-nitroacrylates with N,N-, N,O-, and N,S-Binucleophiles
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The reactions of β-aryl(heteryl)-α-nitroacrylates with N,N-, N,O-, and N,S-binucleophiles proceed regiospecifically through the initial formation of the AdN products, among which only the product from oaminothiophenol was isolated. The conditions of converting the S-adducts into 2-aryl(heteryl)benzothiazole were found. The N-adducts formed in the reaction with hydrazine, o-phenylenediamine, and o-aminophenol undergo immediately the spontaneous transformation into the linear (azine, azomethine) or heterocyclic (benzimidazole) structures. Pleiades Publishing, Ltd., 2012.
- Baichurina,Baichurin,Filippenko,Aboskalova,Berestovitskaya
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p. 1400 - 1408
(2013/01/15)
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- Facile method for the conversion of semicarbazones/thiosemicarbazones into azines (Under Microwave Irradiation) and oxadiazoles (By Grinding)
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In an effective transformation, semicarbazones/thiosemicarbazones are smoothly converted into azines under microwave irradition. Oxadiazoles are also obtained from semicarbazones by reaction with bromine generated in situ via a grinding reaction in the solid phase. Taylor &Francis Group, LLC.
- Chattopadhyay, Gautam,Ray, Partha Sinha
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p. 2607 - 2614
(2011/08/07)
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- Selective and convenient protection of aldehydes as azines under solvent-free conditions
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Aldehydes can be easily protected as azines in the presence of hydrazine monohydrochloride and ferric chloride under solvent-free conditions. The major advantages of this method are: operational simplicity, ready availability, selectivity, general applicability, mild reaction conditions with low cost of the reactants, short reaction times and excellent yields.
- Eshghi, Hossein,Hosseini, Mosayyeb
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experimental part
p. 636 - 638
(2009/05/11)
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- β-Acetyl-β-nitrostyrenes: Structure and use for synthesis of heteryl-containing structures
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1H, IR, and electronic absorption spectroscopy and X-ray diffraction analysis were used to establish that 1-acetyl-1-nitro-2-phenyl-and 2-(p-methoxyphenyl)ethenes have Z configuration, and their 2-(p-N, Ndimethylaminophenyl)-substituted analog exists in chloroform-d 3 as a mixture of Z and E isomers. The reactions of gem-acetylnitroethenes with N-methylpyrrole were shown to involve alkylation at the C2-reaction center of the heterocycle. The reactions of these nitroalkenes with hydrazine form pyrazoles and azines, with acetylhydrazine, the corresponding hydrazones (via transalkenylation), and with sodium azide, acetylsubstituted 1,2,3-triazoles.
- Aboskalova,Smirnova,Kataeva,Baichurin,Fel'gendler,Berkova,Berestovitskaya
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experimental part
p. 1711 - 1718
(2009/02/06)
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- Optically active transition metal-diamine compound and process for producing optically active alcohol with the same
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The present invention provides a water-soluble transition metal-diamine complex which can be easily separated from reaction products through liquid separation, etc. and is recycleable; an optically active diamine compound constituting the ligand of the complex; and a catalyst for asymmetric synthesis which comprises these. The present invention relates to a water-soluble optically active transition metal-diamine complex represented by the formula (2): [wherein R1 and R2 each represents hydrogen, a hydrocarbon group, —SO2R13 (wherein R13 is a hydrocarbon group, substituted amino, etc.), etc.; R3 to R12 each represents hydrogen, a hydrocarbon group, alkoxy, substituted amino, etc.; M represents a transition metal; X represents halogen; L represents a ligand; and * indicates an asymmetric carbon atom; provided that at least one of R3 to R7 and R8 to R12 is substituted amino], a catalyst for asymmetric synthesis containing the complex, and a process for producing an optically active alcohol, which comprises using the catalyst to asymmetrically reduce a ketone.
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Page/Page column 20
(2008/06/13)
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- The catalytic olefination reaction of aldehydes and ketones with CBr 3CF3
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The new approach of catalytic olefination reaction (COR) has been used to convert aromatic and aliphatic aldehydes and ketones to 2-bromo-3,3,3- trifluoroprop-1-enes by the treatment of corresponding hydrazones with CBr 3CF3 under copper(I) catalysis conditions. The reaction proceeds stereoselectively, the target alkenes were obtained in good yields.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 907 - 913
(2007/10/03)
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- A novel approach to 2-chloro-2-fluorostyrenes
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A new general catalytic olefination reaction (COR) of aromatic and heteroaromatic aldehydes and ketones was applied to synthesise 2-chloro-2-fluorostyrenes. The two-stage procedure includes the transformation of carbonyl compounds into hydrazones followed by treatment with CFCl3 mediated by copper catalysis. Trichlorofluoromethane was used as a chlorofluoromethylene transfer reagent. The reaction proceeds stereoselectively and the target alkenes were obtained in high yield. A proposed mechanism for the reaction is discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Nenajdenko, Valentine G.,Shastin, Alexey V.,Korotchenko, Vasily N.,Varseev, Georgy N.,Balenkova, Elisabeth S.
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p. 302 - 308
(2007/10/03)
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- A convenient synthesis of azines under solvent-free conditions using microwave irradiation
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In an extremely fast method the reaction of hydrazine sulfate with a number of aldehydes and ketones, is accelerated by microwave irradiation under solvent free conditions in the presence of CH2CO2Na/CaCl2 to afford high yields of relevant azines.
- Khouzani-Loghmani, Hossein,Sadeghi, Majid M. M.,Safari, Javad,Abdorrezaie, Mohammad S.,Jafarpisheh, Masood
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- A novel approach to fluoro-containing alkenes
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A new and general one-pot transformation of aromatic aldehydes to fluorinated olefins containing -CH=C(Cl)CF3 or -CH=C(F)CClF2 moieties is described. Freons CCl3CF3 and CCl2FCClF2 were used as trifluoromethyl and difluoromethyl C2-building blocks respectively. A proposed mechanism for the reaction is discussed.
- Korotchenko, Vasily N,Shastin, Alexey V,Nenajdenko, Valentine G,Balenkova, Elisabeth S
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p. 7519 - 7527
(2007/10/03)
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- Solid-state reactivity of the hydrazine-hydroquinone complex
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The solid-state reactivities of the hydrazine-hydroquinone 1:1 complex and of hydrazine hydrochloride with solid aldehydes, ketones, carboxylic acids, thiohydantoin and 4-nitrophenyl isothiocyanate were investigated. Only the hydrazine complex provides quantitative additions, condensations, ring openings and ring closures. The solid-state mechanisms were investigated by atomic force microscopy (AFM) and the far-reaching anisotropic molecular movements are correlated with the crystal packing, both on the hydrazine complex surface and on the surface of two benzaldehydes. The hydrazine moves into the aldehyde crystals for chemical reaction without melting. Characteristic surface features are created by the common phase rebuilding and phase transformation on both the hydrazine-donating and -accepting crystals. Copyright
- Kaupp, Gerd,Schmeyers, Jens
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p. 388 - 394
(2007/10/03)
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- Oxidative Transformations of Aldazines and Ketazines with Organic Peroxyacids
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Oxidation of aromatic aldazines and ketazines with various peroxycarboxylic acids was investigated.It was found that one part of azine molecule 2 was converted into carbonyl compound 1 or related acid 3 while the second part was transformed into carboxylic ester 4 related to peroxyacid used as an oxidant.It was revealed that aromatic azines could be used as a source of diazaarylmethanes and mechanisms of reactions studied were postulated. aldazines, carboxylic esters, ketazines, oxidation, peroxycarboxylic acids
- Mlochowski, J.,Giurg, M.
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p. 2333 - 2342
(2007/10/02)
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- CONDENSATION OF p-(DIMETHYLAMINO)BENZALDEHYDE WITH HYDRAZINE IN A MICELLAR MEDIUM
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The rate of the condensation of p-(dimethylamino)benzaldehyde with hydrazine in aqueous solution and the yield of the product (the amine) rise by two orders of magnitude in presence of micelles of sodium dodecyl sulfate.It was found that the micellar effect in the kinetics is manifested at the first dimolecular stage of the reaction of the aldehyde with hydrazine and is explained by the concentrating of the reactants in the micelles.The rate constants of the condensation of hydrazine with a number of substituted benzaldehydes conform to the Hammett equation with a low positive value of ρ.
- Yatsimirskii, A. K.,Yatsimirskaya, N. T.,Krivova, S. B.
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p. 752 - 757
(2007/10/02)
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- Charge-tansfer complexes of substituted aromatic azines and ?-acceptors
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Charge-transfer complexes of symmetrically substituted aromatic azines with tetracyanoethylene (TCNE) and 1,4-benzoquinones in methylene chloride have been investigated spectrophotometrically.The spectral data, molar extinction coefficients and transition energies of the complexes formed as well as the ionization potentials of the electron donors are reported.Both BENSI-HILDEBRAND and JOB methods have been applied in determination of association and apparent formation constants respectively.Substituent effect on charge-transfer equilibria of the substituted azines has been discussed.
- Mourad, Aboul-Fetouh E.
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p. 933 - 938
(2007/10/02)
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