- Isophthaloyl-Based Selective Fluorescence Receptor for Zn (II) Ion in Semi-Aqueous Medium
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A novel Isophthaloyl-based symmetrical (12E,21E)-N1’,N3’-bis(2-hydroxybenzylidene) isophthalohydrazide, receptor (1) was synthesized and characterized using various spectroscopic technique. The reorganization ability of receptor (1) was evaluated in semi-aqueous medium and shows significant enhancement in fluorescence intensity for Zn (II) ion over various metal ions in CH3CN:H2O (1:1, v/v). The 1:2 binding stoichiometry between receptor (1) and Zn (II) ion was established using Job’s plot and the proposed complex structure was calculated by applying Density Functional Theory (DFT) method. The binding constant (Ka) of receptor (1) with Zn (II) ion was established with the Benesi-Hildebrand plot, Scatchard and Connor’s plot and the values are 1.00 × 104?M?1, 1.05× 104?M?1 and 1.05× 104?M?1 respectively. The limit of detection (LOD) and limit of quantification (LOQ) of receptor (1) and Zn (II) ion was 0.292?μM and 0.974?μM respectively. The binding mode was due to photo-induced electron transfer (PET) and the coordination of Zn (II) ion with C = N hydroxyl group of receptor (1). Electrochemical analysis of metal free receptor (1) and with Zn (II) ion also confirmed the formation of complex.
- Khadke,Patil,Patil,Borhade
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- Hydrazine functionalized probes for chromogenic and fluorescent ratiometric sensing of pH and F-: Experimental and DFT studies
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Two novel hydrazine based sensors, BPPIH (N1,N3-bis(perfluorophenyl)isophthalohydrazide) and BPBIH (N1′,N3′-bis(perfluorobenzylidene)isophthalohydrazide), are presented here. BPPIH is found to be a highly sensitive pH sensor in the pH range 5.0 to 10.0 in a DMSO-water solvent mixture with a pKa value of 9.22. Interesting optical responses have been observed for BPPIH in the above mentioned pH range. BPBIH on the other hand turns out to be a less effective pH sensor in the above mentioned pH range. The increase in fluorescence intensity at a lower pH for BPPIH was explained by using density functional theory. The ability of BPPIH to monitor the pH changes inside cancer cells is a useful application of the sensor as a functional material. In addition fluoride (F-) selectivity studies of these two chemosensors have been performed and show that between them, BPBIH shows greater selectivity towards F-. The interaction energy calculated from the DFT-D3 supports the experimental findings. The pH sensor (BPPIH) can be further interfaced with suitable circuitry interfaced with desired programming for ease of access and enhancement of practical applications.
- Roy Chowdhury, Additi,Mondal, Amita,Roy, Biswajit Gopal,Bose, Jagadeesh C.K.,Mukhopadhyay, Sudit,Banerjee, Priyabrata
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- A Strategy to Synthesize Molecular Knots and Links Using the Hydrophobic Effect
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Conventional approaches to the synthesis of molecular knots and links mostly rely on metal templation. We present here an alternative strategy that uses the hydrophobic effect to drive the formation of complex interlocked structures in water. We designed an aqueous dynamic combinatorial system that can generate knots and links. In this system, the self-assembly of a topologically complex macrocycle is thermodynamically favored only if an optimum packing of all its components minimizes the hydrophobic surface area in contact with water. Therefore, the size, geometry, and rigidity of the initial building blocks can be exploited to control the formation of a specific topology. We illustrate the validity of this concept with the syntheses of a Hopf link, a Solomon link, and a trefoil knot. This latter molecule, whose self-assembly is templated by halides, binds iodide with high affinity in water. Overall, this work brings a fresh perspective on the synthesis of topologically complex molecules: Solvophobic effects can be intentionally harnessed to direct the efficient and selective self-assembly of knots and links.
- Cougnon, Fabien B.L.,Caprice, Kenji,Pupier, Marion,Bauzá, Antonio,Frontera, Antonio
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- A reversible and efficient probe for dual mode recognition of Al3+ and Cu2+ with logic gate behaviour: Crystal structure, theoretical and in-vivo bio-imaging investigations
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This work presents the synthesis, characterization, crystal structure and spectroscopic investigations of isophthalohydrazide based probe. Among various tested metal ions, the probe selectively detects Al3+ and Cu2+ in aqueous ethanol via fluorometric and colorimetric methods, respectively. It displays a fluorescence “turn-on” response with Al3+ and visual colour change from colourless to yellow with Cu2+. Sensing mechanism is explored with UV–Vis, fluorescence spectroscopy and 1H NMR titration, and confirmed with computational results. Suppression of C[dbnd]N isomerization and photo-induced electron transfer (PET) along with chelation enhanced fluorescence emission (CHEF) result in “turn-on” fluorescence with Al3+ while ligand to metal charge transfer (LMCT) accounts for visual colour change with Cu2+. Job's plot and HRMS confirm 1:2 (L:M) stoichiometry. The probe also exhibits efficient reversibility and reproducibility with EDTA which are successfully mimicked with combinatorial logic gate and truth table. Additionally, solid state applications and bio-imaging investigation on gut tissue of Drosophila 3rd instar larvae are performed.
- Choudhury, Lokman H.,Kumar Pandey, Anoop,Kumar, Rohit,Singh, Vinod P.,Srikrishna, S.,Upadhyay, Chandan,Yadav, Pranjalee
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- FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
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- Ultralow-Molecular-Weight Stimuli-Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides
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The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140–200) hydrazide-derived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can self-assemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π–π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1′-binaphthalene-2,2′-diamine and S2? through much different times of gel re-formation and blue-green color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.
- Wu, Dehua,Song, Jintong,Qu, Lang,Zhou, Weilan,Wang, Lei,Zhou, Xiangge,Xiang, Haifeng
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p. 3370 - 3378
(2020/10/02)
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- Preparation method and application of cobalt organic macro-cyclic compound
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The invention belongs to the technical field of supramolecular chemistry, and relates to a preparation method and application of a cobalt organic macro-cyclic compound. The preparation method is characterized in that Co in a transition metal cobalt salt is used as a node, L is used as a ligand for reaction to prepare the metal organic macro-cyclic compound, and the synthetic route is as follows: Co+L-> Co-L; wherein the ligand L is selected from DTP; the transition metal cobalt salt is selected from one of cobalt chloride hexahydrate, cobalt nitrate hexahydrate, cobalt sulfate heptahydrate, cobalt tetrafluoroborate hexahydrate or cobalt perchlorate hexahydrate. The prepared cobalt organic macro-cyclic compound is low in raw material price and high in yield. The obtained compound isstable in chemical property, can catalyze an intra-molecular dehydrogenation coupling reaction of N-phenyl enamine, realizes efficient and green dehydrogenation, and has an important realistic meaning.
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Paragraph 0027; 0028
(2020/06/04)
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- SAR Studies on Aromatic Acylhydrazone-Based Inhibitors of Fungal Sphingolipid Synthesis as Next-Generation Antifungal Agents
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Recently, the fungal sphingolipid glucosylceramide (GlcCer) synthesis has emerged as a highly promising new target for drug discovery of next-generation antifungal agents, and we found two aromatic acylhydrazones as effective inhibitors of GlcCer synthesis based on HTP screening. In the present work, we have designed libraries of new aromatic acylhydrazones, evaluated their antifungal activities (MIC80 and time-kill profile) against C. neoformans, and performed an extensive SAR study, which led to the identification of five promising lead compounds, exhibiting excellent fungicidal activities with very large selectivity index. Moreover, two compounds demonstrated broad spectrum antifungal activity against six other clinically relevant fungal strains. These five lead compounds were examined for their synergism/cooperativity with five clinical drugs against seven fungal strains, and very encouraging results were obtained; e.g., the combination of all five lead compounds with voriconazole exhibited either synergistic or additive effect to all seven fungal strains.
- Del Poeta, Maurizio,Haranahalli, Krupanandan,Lazzarini, Cristina,Mallamo, John,McCarthy, J. Brian,Ojima, Iwao,Pathiranage, Senuri,Sun, Yi,Zambito, Julia
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- Promising bactericidal approach of dihydrazone analogues against bio-film forming Gram-negative bacteria and molecular mechanistic studies
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Gram-negative members of the ESCAPE family are more difficult to treat, due to the presence of an additional barrier in the form of a lipopolysaccharide layer and the efficiency of efflux pumps to pump out the drugs from the cytoplasm. The development of alternative therapeutic strategies to tackle ESCAPE Gram-negative members is of extreme necessity to provide a solution to the cause of life-threatening infections. The present investigations demonstrated that compounds 17, 20, 25 and 26 possessing the presence of electron donating (OH and OCH3) groups on the phenyl rings are highly potent; whereas compounds 9, 10, 15, 16, 18, 33 and 36 showed moderate activity against Gram-negative bacteria. An excellent dose-dependent antibacterial activity was established compared to that of the standard antibiotic ampicillin. Significant anti-biofilm properties were measured quantitatively, showing optical density (O.D) values of 0.51 ± 015, 0.63 ± 0.20, 0.38 ± 0.07 and 0.62 ± 0.11 at 492 nm and the leakage of cellular components by the compounds, such as 17, 20, 25 and 26, increased the O.D. of respective treated samples compared to the control. In addition, the implication of experimental results is discussed in the light of the lack of survivability of planktonic bacteria and biofilm destruction in vitro. These results revealed the great significance of the development of a new generation of synthetic materials with greater efficacy in anti-biofilm properties by targeting to lock the bio-film associated protein Bap in Gram-negative bacteria.
- Rakesh,Vivek,Manukumar,Shantharam,Bukhari,Qin, Hua-Li,Sridhara
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p. 5473 - 5483
(2018/04/30)
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- Novel Isophthalohydrazide-cDB24C8 cryptand derivative for the selective recognition of fluoride ion: An experimental and DFT study
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A highly selective and sensitive novel Isophthalohydrazide-cDB24C8 cryptand derivative was developed for fluoride recognition at a very low concentration of 2.31 × 10?10 M. The binding was established by UV–Vis, fluorescence and 1H NMR titration. The receptor formed very strong H-bonded complex with fluoride, furnished a sharp new UV–Vis absorption peak at 280 nm which was also supported by the DFT-study. The fluorescence emission spectra showed large quenching up to 79.13% upon addition of fluoride.
- Bora, Sankar Jyoti,Dutta, Rakesh,Kalita, Dhruba Jyoti,Chetia, Bolin
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p. 225 - 231
(2018/06/26)
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- Multi-targeted dihydrazones as potent biotherapeutics
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Hydrazone compounds were considered as a useful moiety in drug design development. Therefore, these studies were aimed at the synthesis of new dihydrazones and were screened for their in vitro H+/K+-ATPase and anti-inflammatory activities. The results revealed that compounds 9 (22 ± 0.62 μg/mL), 10 (26 ± 0.91 μg/mL), 15 (24 ± 0.44 μg/mL), 16 (28 ± 0.63 μg/mL), 17 (12 ± 0.38 μg/mL), 18 (14 ± 0.47 μg/mL), 19 (26 ± 0.54 μg/mL), 20 (16 ± 0.41 μg/mL), 25 (06 ± 0.68 μg/mL) and 26 (08 ± 0.43 μg/mL) showed excellent H+/K+-ATPase activity and their IC50 value were lower than the standard drug Omerazole (48 ± 0.12 μg/mL). Compounds 5 (28 ± 0.65 μg/mL), 6 (24 ± 0.61 μg/mL), 7 (28 ± 0.64 μg/mL), 8 (26 ± 0.45 μg/mL), 11 (30 ± 0.74 μg/mL), 12 (28 ± 0.40 μg/mL), 13 (32 ± 0.24 μg/mL), 14 (30 ± 0.55 μg/mL) and 21 (08 ± 0.47 μg/mL), 22 (12 ± 0.47 μg/mL), 23 (10 ± 0.51 μg/mL) and 24 (14 ± 0.84 μg/mL) showed better anti-inflammatory activity compared to standard indomethacin (44 ± 0.15 μg/mL). The structure activity relationship (SAR) showed that, electron donating groups (OH, OCH3) favored the H+/K+-ATPase and antioxidants activity, whereas, electron withdrawing groups (F, Cl, Br and NO2) favored the anti-inflammatory activity. Furthermore, molecular docking study was performed to investigate the binding interactions of the most active analogs with the active site of H+/K+-ATPase enzyme. Compounds 25 (G-score = ?9.063) and 26 (G-score = ?8.977) showed the highest docking G-scores for H+/K+-ATPase inhibition activity.
- Li, Chen,Sridhara,Rakesh,Vivek,Manukumar,Shantharam,Qin, Hua-Li
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p. 389 - 395
(2018/09/13)
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- A supramolecular porous material comprising Fe(ii) mesocates
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The dinuclear mesocate [Fe2L3](BF4)4, 1, is a supramolecular building block for a microporous material. Structural analysis reveals that extensive noncovalent interactions in the solid state generate a 3D framework with microporous channels. These channels are permanently accessible to incoming guest molecules and adsorption isotherms demonstrate that the material has a high selectivity for CO2 over N2
- Wilson, Benjamin H.,Scott, Hayley S.,Qazvini, Omid T.,Telfer, Shane G.,Mathonière, Corine,Clérac, Rodolphe,Kruger, Paul E.
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p. 13391 - 13394
(2018/12/13)
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- A containing double (2-substituted-sulfonyl -1, 3, 4-oxadiazol-5-yl) heterocyclic compound and use thereof
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The invention belongs to the field of chemical engineering and pesticides, and particularly relates to a heterocyclic compound containing bis(2-substituted sulfonyl-1,3,4-oxadiazole-5-radical) and application thereof. The structure of the heterocyclic compound is shown in the specification. In a general formula, R is hydrogen, C1-C5 alkyl radicals, C1-C5 halogenated alkyl radicals, C2-C5 alkenyl, and ester, benzyl or substituted benzyl of C2-C5, and Z is hydrocarbyl or substituted hydrocarbon thereof, phenyl, substituted phenyl, biphenylyl, substituted biphenylyl, naphthyl, substituted naphthyl, diphenyl hydrocarbyl, substituted diphenyl hydrocarbyl, and diphenyl ether or substituted diphenyl ether. The heterocyclic compound has very good inhibitory activity on rhizoctonia solani, fusarium asiaticum, borrytis cinerea, physalospora piricala, helminthossporium oryzae, tobacco bacterial wilt and rice brown blotches, can be applied to prevention and control of plant diseases and has wide application prospect.
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- Nanomolar fluorogenic detection of Al(iii) by a series of Schiff bases in an aqueous system and their application in cell imaging
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Three positional isomers of a Schiff base containing -OH as end groups have been synthesized and evaluated for selective Al(iii) detection due to inhibition of ESIPT, PET and activation of CHEF in 70% aqueous medium. Devoid of any conventional fluorophore, these sensors have nanomolar detection limits with high quantum yields and naked eye sensing of Al(iii). Moreover, these probes have been demonstrated to enable the Al(iii) detection in live human HeLa cells and rat C6 glioma cells using a confocal microscope. the Partner Organisations 2014.
- Sharma, Sanyog,Hundal, Maninder Singh,Walia, Amandeep,Vanita, Vanita,Hundal, Geeta
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p. 4445 - 4453
(2014/06/23)
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- Synthesis of some novel bis-1,2,4-triazole and bis-1,3,4-thiadiazole derivatives from terephthaloyl and isophthaloyl chlorides
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An efficient synthesis of novel bis-1,2,4-triazole and bis-1,3,4- thiadiazole derivatives starting from terephthaloyl and isophthaloyl chlorides is described. Terephthaloyl or isophthaloyl chloride was allowed to react with hydrazine hydrate in refluxing ethanol to give a corresponding bis-hydrazide derivative. Further reaction of these compounds with isothiocyanates gave bis-thiosemicarbazide derivatives, which then underwent cyclization to bis-1,3,4-thiadiazoles in the presence of sulfuric acid. The cyclization of these compounds in the presence of sodium hydroxide resulted in the formation of bis-1,2,4-triazole-3-thioles. The structure of these compounds was characterized by IR, NMR, and elemental analysis.
- Mobinikhaledi, Akbar,Foroughifar, Naser,Rafiee, Abdolhossein
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p. 265 - 269
(2013/09/02)
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- Dual channel selective fluorescence detection of Al(iii) and PPi in aqueous media with an 'off-on-off' switch which mimics molecular logic gates (INHIBIT and EXOR gates)
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In this study, we have synthesized a simple Schiff base type isophthaloyl salicylaldehyde hydrazone (ISH) moiety which selectively detects Al(iii) and PPi with a fluorescence enhancement at two different wavelengths in aqueous solution. The sensing phenomenon is also reversible and thus the sensor beautifully mimics logic gates (INHIBIT and EXOR gates).
- Goswami, Shyamaprosad,Manna, Abhishek,Paul, Sima,Aich, Krishnendu,Das, Avijit K.,Chakraborty, Shampa
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p. 8078 - 8085
(2013/07/28)
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- Synthesis and antibacterial activities of 13-bis[3-N-acetyl-2-aryl-1,3,4- oxadiazoline-5-yl]benzenes
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Dimethyl isophthalate (1) was reacted with 80% hydrazine hydrate in refluxing ethanol for 16 h to give isophthalic dihydrazide (2). Condensation of 2 with aromatic aldehydes afforded corresponding hydrazones 3a-3i. Cyclization of 3a-3i with acetic anhydride in refluxing for 4-5 h afforded 1,3-Bis[3-N-acetyl-2-aryl-1,3,4-oxadiazoline-5-yl]benzenes (4a-4i). The structures of 4a-4i were characterized by elementary analyses, IR, 1H NMR, and MS spectroscopy. The preliminary antibacterial tests showed that most of them were effective against S.aureus.
- Li, De-Jiang,Dan, Fei-Jun,Fu, He-Qing
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p. 101 - 105
(2008/09/20)
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- Isolation of Anhydrous Hydrazine as Stable Inclusion Complexes with Hydroquinone and p-Methoxyphenol, and their Solid State Reaction with Esters which gives Pure Hydrazides
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Anhydrous hydrazine is isolated in a pure state as a stable inclusion complex crystal with hydroquinone or p-methoxyphenol, the X-ray structure of which have been analysed; the solid-state reaction of the hydrazine inclusion complex and esters gives hydrazides which are virtually uncontaminated with acid hydrazine salt byproducts.
- Toda, Fumio,Hyoda, Shunji,Okada, Kengo,Hirotsu, Ken
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p. 1531 - 1532
(2007/10/02)
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