- Chemistry of diazocarbonyl compounds: XXVII. Thermolysis and photolysis of diazirines, derivatives of 1,3-dioxane-4,6-dione
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Photolysis of diazirines, 1,3-dioxane-4,6-dione derivatives, occurs in the presence of methanol or dimethyl sulfide as carbene traps without a formation of carbene intermediates. It was established for the first time that the thermolysis and photolysis of diazirines from the 1,3-dioxane-4,6-dione series led mainly to Wolff rearrangement with a subsequent formation of 5-oxo-1,3-dioxolane-4-carboxylic acids or their derivatives. The data obtained show that the α-oxodiazirines are the key intermediates in the photolysis and Wolff rearrangement of α-diazocarbonyl compounds. Nauka/Interperiodica 2006.
- Shevchenko,Khimich,Platz,Nikolaev
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- Search for dioxocarbenes in photochemical reactions of 5-diazo-4,6-dioxo-1, 3-dioxanes, associated diazirines, and S-ylides
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On direct photolysis of 2,2-dialkyl-5-diazo-4,6-dioxo-1,3-dioxanes in the presence of pyridine, methanol or dimethyl sulfide as carbene traps, the yield of 'carbene' products does not exceed 27-28%. At the same time photochemical transformations of the re
- Shevchenko,Khimich,Platz,Nikolaev
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- Experimental and Theoretical Investigation of Reversible Interconversion, Thermal Reactions, and Wavelength-Dependent Photochemistry of Diazo Meldrum's Acid and Its Diazirine Isomer, 6,6-Dimethyl-5,7-dioxa-1,2-diaza-spiro[2,5]oct-1-ene-4,8-dione
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The photochemical or thermal decomposition of diazo Meldrum's acid (1) in methanolic solutions yields ketoester 3a, the product of the Wolff rearrangement, while products produced from the singlet carbene were not detected. This observation, combined with the analysis of activation parameters for the thermal decomposition of 1, as well as with the results of DFT B3PW91/6-311+G(3df,2p) and MP2/aug-cc-pVTZ//B3PW91/6-311+G(3df,2p) calculations, allows us to conclude that the Wolff rearrangement of 1 is a concerted process. The outcome of the photolysis of diazo Meldrum's acid depends on the wavelength of irradiation. Irradiation with 254 nm light results in an efficient (Φ254 = 0.34) photo-Wolff reaction, while at 355 nm, the formation of diazirine 2 becomes the predominant process (Φ 350 = 0.024). This unusual wavelength selectivity indicates that Wolff rearrangement and isomerization originate from different electronically excited states of 1. The UV irradiation of diazirine 2 leads to the loss of nitrogen and the Wolff rearrangement, apparently via a carbene intermediate. This process is accompanied by a reverse isomerization to diazo Meldrum's acid. Triplet-sensitized photolysis of both isomers results in the formation of Meldrum's acid, the product of a formal reduction of 1 and 2. Mild heating of diazirine 2 produces quantitative yields of diazo Meldrum's acid. The activation parameters for thermal reactions of diazo 1 and diazirino 2 isomers were determined in aqueous and dioxane solutions.
- Bogdanova, Aneta,Popik, Vladimir V.
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- Crystal-to-Gel Transformation Stimulated by a Solid-State E→Z Photoisomerization
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The molecule (E)-(5-(3-anthracen-9-yl-allylidene)-2,2-dimethyl-[1,3] dioxane-4,6-dione) (E-AYAD) undergoes E→Z photoisomerization. In the solid state, this photoisomerization process can initiate a physical transformation of the crystal that is accompanied by a large volume expansion (ca. 10 times), loss of crystallinity, and growth of large pores. This physical change requires approximately 10 % conversion of the E isomer to the Z isomer and results in a gel-like solid with decreased stiffness that still retains its mechanical integrity. The induced porosity allows the expanding gel to engulf superparamagnetic nanoparticles from the surrounding liquid. The trapped superparamagnetic nanoparticles impart a magnetic susceptibility to the gel, allowing it to be moved by a magnetic field. The photoinduced phase transition, starting with a compact crystalline solid instead of a dilute solution, provides a new route for in situ production of functional porous materials.
- Tong, Fei,Chen, Shaolong,Li, Zhiwei,Liu, Mingyue,Al-Kaysi, Rabih O.,Mohideen, Umar,Yin, Yadong,Bardeen, Christopher J.
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- Rhodium(II)-catalyzed olefin cyclopropanation with the phenyliodonium ylide derived from Meldrum's acid
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The phenyliodonium ylide 3a derived from Meldrum's acid reacts with olefins in the presence of Rh(II) carboxylate catalysts to afford cyclopropanes. The reaction is stereospecific. Enantioselectivities of up to 63% have been observed for the cyclopropanation of pent-1-ene. No 1,3-cycloadducts are formed between 3a and polarized olefins such as furan or 2,3-dihydrofuran.
- Mueller, Paul,Allenbach, Yves,Robert, Estelle
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- Chromogenic and fluorogenic chemodosimeter derived from Meldrum's acid detects cyanide and sulfide in aqueous medium
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The detection of anionic analytes is of extreme importance since many of these species are toxic and they play a variety of roles in biological, environmental and industrial processes. However, the techniques currently used for their detection are costly and highly complex and thus the search for new detection methods for these analytes is a growing area of scientific research. In this regard, techniques involving the use of molecular and supramolecular devices are being developed, which offer simplicity, precision, reliability and low cost, in both quantitative and qualitative analyses. Herein, a novel compound was synthesized through the Knoevenagel condensation reaction between Meldrum's acid and pyrene–1–carbaldehyde. The final product, 2,2–dimethyl–5–(pyren–1–ylmethylene)–1,3–dioxane–4,6–dione (1), was completely characterized. The performance of compound 1 as a chemodosimeter for the detection of CN? and sulfide was verified. The compound was shown to be simultaneously a selective chromogenic (on–off) and fluorogenic (off–on) chemodosimeter for CN? and sulfide in an organic–aqueous system, with a 1:1 anion:compound stoichiometry. To make the system selective only for CN?, Pb(NO3)2 was added so that all of the sulfide present in the sample precipitated and became unavailable to interact with the chemodosimeter, leaving only the CN? available to react with the system. In all cases the limits of detection were below those established by WHO, with the analytical tests carried out by means of the fluorescence technique allowing the detection of CN? at 10?8 mol L?1. Finally, the system could be used for the detection of CN? spiked in tap water samples.
- Ferreira, Natasha L.,de Cordova, Letícia M.,Schramm, Adriana D.S.,Nicoleti, Celso R.,Machado, Vanderlei G.
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- Method for synthesizing coumarin-3-carboxylic acid compounds by one-pot two-step method
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The invention relates to a method for synthesizing coumarin-3-carboxylic acid compounds by a one-pot two-step method. The structural formula of the coumarin-3-carboxylic acid compounds is shown in the description, wherein R1 is H , Cl , Br, NO2 , CH3 and HO . According to the synthesis process of the coumarin-3-carboxylic acid compounds, malonic acid, acetone and substituted salicylaldehyde serve as raw materials, iodine serves as a catalyst, acetic anhydride serves as a solvent, a series of coumarin-3-carboxylic acid compounds are synthesized through a one-pot cascade reaction, and the efficiency and the yield are greatly improved compared with a fractional step method.
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Paragraph 0053; 0055-0056; 0079; 0081-0083
(2021/06/12)
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- Chemical synthesis, molecular docking and MepA efflux pump inhibitory effect by 1,8-naphthyridines sulfonamides
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This study aimed to evaluate the antibacterial activity and to verify, in silico and in vitro, the inhibition of efflux mechanisms using a series of synthesized 1,8-naphthyridines sulfonamides against Staphylococcus aureus strains carrying MepA efflux pumps. The chemical synthesis occurred through the thermolysis of the Meldrum's acid adduct. The sulfonamide derivatives were obtained by the sulfonylation of 2-amino-5?chloro-1,8-naphthyridine with commercial benzenesulfonyl chloride. Antibacterial activity was assessed by the broth microdilution test. Efflux pump inhibitory capacity was evaluated in silico by molecular docking and in vitro by analyzing synergistic effects on ciprofloxacin and ethidium bromide (EtBr) and by EtBr fluorescence emission assays. The following 1,8-naphthyridines were synthesized: 4-methyl-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10a); 2,5-dichloro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10b); 4-fluoro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10c); 2,3,4-trifluoro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10d); 3-trifluoromethyl-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10e); 4?bromo-2,5-difluoro-N-(5?chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide (Compound 10f). The 1,8-naphthyridines derivatives associated with sulfonamides did not show antibacterial activity. However, they showed a favorable pharmacokinetic profile with possible MepA efflux pump inhibitory action, demonstrated in molecular docking. In addition to the promising results in reducing the concentration of intracellular EtBr. 1,8-naphthyridines act as putative agents in the inhibitory action of the MepA efflux pump.
- Oliveira-Tintino, Cícera Datiane de Morais,Tintino, Saulo Relison,Muniz, Débora Feitosa,Rodrigues dos Santos Barbosa, Cristina,Pereira, Raimundo Luiz Silva,Begnini, Iêda Maria,Rebelo, Ricardo Andrade,da Silva, Luiz Everson,Mireski, Sandro Lucio,Nasato, Michele Caroline,Krautler, Maria Isabel Lacowicz,Pereira, Pedro Silvino,Balbino, Tereza Cristina Leal,da Costa, José Galberto Martins,Rodrigues, Fabiola Fernandes Galv?o,Teixeira, Alexandre Magno Rodrigues,Barreto, Humberto Medeiros,de Menezes, Irwin Rose Alencar,Coutinho, Henrique Douglas Melo,da Silva, Teresinha Gon?alves
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- Properties of a furan ring-opening reaction in aqueous micellar solutions for selective sensing of mesalazine
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A novel and efficient non-azo formation based method was developed for trace sensing of mesalazine (MES), a pharmaceutical aromatic amine. MES was simply coupled with a Meldrum's activated furan (MAF) reagent via a furan ring opening reaction to form a colored product. The intense purple colored solution was detected at 575 nm. The reaction of MES with MAF was monitored by employing 1H NMR spectroscopy and mass spectrometry. In addition, density functional theory (DFT) was applied to optimize the structure of the colored product and its λmax (the wavelength of maximum absorbance) in dimethyl sulfoxide and water. The colored product was considered in three possible structures, and the most possible structures in dimethyl sulfoxide and in water were identified by employing the DFT calculations. Both of the most possible structures indicated only a local excitation in their λmax and no charge transfer was observed. However, one of the structures in dimethyl sulfoxide presented charge transfer properties occurring through N–C[dbnd]C–C moiety. A univariate optimization method was also used to attain the optimum condition for analysis. In addition, the dependence of the analytical response on the three main affecting parameters (reaction time (X1), Triton X-100 concentration (X2) and MAF concentration (X3)) was identified by employing a central composite design (CCD) approach. The CCD study showed that the analytical response depends complexly on the parameters. Beer's law was obeyed within the range of 0.06–9.30 μg mL?1 of MES (155 fold linearity) at 575 nm, under the optimum condition introduced by the CCD approach. Also, the limit of detection was obtained 0.04 μg mL?1 of MES. The method showed precision (as relative standard deviation) and accuracy (as recovery) within the ranges of 0.6–3.2 % and 96.3–100.8%, respectively. Various organic and inorganic species, amino-pharmaceuticals, and amino acids were tested to evaluate the selectivity of the method. The selectivity of the analytical method was satisfactory. The method was successfully applied for detection of MES in various water matrices and pharmaceutical tablets.
- Sabahi-Agabager, Leila,Eskandari, Habibollah,Nasiri, Farough,Shamkhali, Amir Nasser,Baghi Sefidan, Somayyeh
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- Enhancement of anticancer potential of pterostilbene derivative by chalcone hybridization
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Pterostilbene, a natural metabolite of resveratrol, has been indicated as a potent anticancer molecule. Recently, several pterostilbene derivatives have been reported to exhibit better anticancer activities than that of the parent pterostilbene molecule. In the present study, a series of pterostilbene derivatives were designed and synthesized by the hybridization of pterostilbene, chalcone, and cinnamic acid. The cytotoxic effect of these hybrid molecules was determined using two oral cancer cell lines, HSC-3 and OECM-1. (E)-3-(2-((E)-4-Hydroxystyryl)-4,6-dimethoxyphenyl)-1-(2-methoxyphenyl)prop-2-en-1-one (4d), with IC50 of 16.38 and 18.06 μM against OECM-1 and HSC-3, respectively, was selected for further anticancer mechanism studies. Results indicated that compound 4d effectively inhibited cell proliferation and induced G2/M cell cycle arrest via modulating p21, cyclin B1, and cyclin A2. Compound 4d ultimately induced cell apoptosis by reducing the expression of Bcl-2 and surviving. In addition, cleavage of PARP and caspase-3 were enhanced following the treatment of compound 4d with increased dose. To conclude, a number of pterostilbene derivatives were discovered to possess potent anticancer potentials. Among them, compound 4d was the most active, more active than the parent pterostilbene.
- Chen, Yeh-Long,Chen, Yi-Jin,Hsieh, Ya-Ju,Hsu, Chia-Chi,Ke, Chien-Chih,Tai, Hsiao-Ting,Tang, Kai-Wei,Tseng, Chih-Hua,Tzeng, Cherng-Chyi
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- Synthesis of new chalcone-based homoserine lactones and their antiproliferative activity evaluation
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Three series of new homoserine lactone analogs were efficiently synthesized starting from methionine and further evaluated for their antiproliferative activity against different cancer cell lines. Among these compounds, some of the chalcone containing compounds 6a-n showed acceptable antiproliferative activity against prostate cancer cells DU145 and PC-3 with the IC50 values less than 10 μM. Compounds 6c, 6e and 6h inhibited growth of DU145 and PC-3 cells at low micromolar levels with the IC50 values ranging from 3.0 to 5.0 μM, much more potent than natural OdDHL. Compound 6e concentration-dependently inhibited colony formation and cell migration of DU145 cells. A synergistic effect on the growth inhibition and the apoptosis of DU145 cells was observed when compound 6e was used in combination with TRAIL. OdDHL or 6e treatment concentration-dependently activated TRAIL death receptor DR5 which may account for the observed synergistic effect of 6e or OdDHL with TRAIL on the growth inhibition and cell apoptosis. Compound 6e also inhibited migration of DU145 cells in a time- and concentration-dependent manner. The data suggest that quorum sensing molecules OdDHL and 6e may improve the sensitivity of DU145 cells toward TRAIL via activating DR5, compound 6e may be used as a potential lead compound for developing new TRAIL receptor agonists.
- Yu, Bin,Liu, Haoyue,Kong, Xiaoyan,Chen, Xinli,Wu, Chunli
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p. 500 - 511
(2019/01/03)
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- Design, synthesis and biological screening of N-(substituted pyridine-2-yl)-N-(quinoline-2-yl) malonamide as novel anti-HIV-I agents
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A novel series of N1-(substiruted pyridine-2-yl)-N3-(quinoline-2-yl) malonamide derivatives (AK1-AK24) has been rationally designed, synthesized and biologically screened for in vitro anti HIV activity by using reverse transcriptase assay kit (Roche). Out of the synthesized compounds, compound AK1, AK2 and AK3 show potent reverse transcriptase (RT) inhibitor activity and compounds AK4 to AK9, AK11, AK12, AK13 and AK14 show RT inhibitory activity comparable with standard rilpivirine. In docking studies, those compounds show higher G-Score which indicates higher percentage of inhibition of reverse transcriptase during in vitro screening. Insilico pharmacokinetic studies imply that synthesized derivatives have no CYP450 inhibition, no BBB penetration and good oral absorption. Virtual toxicity studies performed by using Toxtree-v 2.6.6 in various computational animal models show high LD50 values and the compounds are found to be non-carcinogenic.
- Kashid, Arun Maruti,Dhawale, Shasbikant
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p. 870 - 879
(2019/05/21)
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- With anti-tumor activity of chlorine oxygen kui derivatives
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The invention relates to a chloroxoquinoline derivatives with anti-tumor activity and specifically relates to compounds of a formula I as shown in the specification and pharmaceutically acceptable salts, solvates and prodrugs thereof, wherein R1 is selected from hydrogen, -C1-6 alkyl, -C2-6 alkenyl, -C2-6 alkynyl and -C1-6 alkyl-phenyl, and the alkyl, the alkenyl, the alkynyl and the phenyl can be optionally substituted by halogens, nitryl, cyan, hydroxyl, -C1-6 alkoxy and phenyl; R3 is selected from hydrogen, -CONHR31 and -COOR32, the R31 and the R32 are independently selected from -C1-6 alkyl and -C1-6 alkylamino, respectively, and the amino can be optionally substituted by 1 to 2 -C1-6 alkyls; R7 is selected from halogens, -C1-6 alkoxy, morpholinyl and piperazine; the formula I is as shown in the specification.
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Paragraph 0319; 0321; 0324
(2017/12/28)
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- Efficient Color-Tunable Copper(I) Complexes and Their Applications in Solution-Processed Organic Light-Emitting Diodes
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A series of dppnc- and neocuproine-based CuI complexes (dppnc=7,8-bis(diphenylphosphino)-7,8-dicarba-nido-undecaborate) are synthesized and the emission color of these CuI complexes can be tuned from green to deep red via rational modification of the neocuproine ligand structure. The molecular structures of the emissive CuI complexes, Cu(dppnc)-G (green emitting), Cu(dppnc)-Y (yellow emitting), and Cu(dppnc)-R (red emitting), are characterized and their electronic structures and related transition properties are elucidated by photo-physical and computational (density functional theory) studies. The calculation results suggest that thermally activated delayed fluorescence (TADF) is the emission mechanism for these CuI complexes. Efficient solution-processed green-, yellow-, and red-emitting OLEDs are fabricated based on the emissive complexes as the dopants. High external quantum efficiency (EQE) of 15.20 % and current efficiency of 48.15 cd A?1 at 1000 cd m?2 are achieved in the green-emitting device with Cu(dppnc)-G. A maximum EQE of 10.17 %, CIE coordinates of (0.61, 0.38) and a maximum electroluminescent peak of 631 nm are achieved in the red device based on Cu(dppnc)-R.
- So, Gary Kwok-Ming,Cheng, Gang,Wang, Jian,Chang, Xiaoyong,Kwok, Chi-Chung,Zhang, Hongxing,Che, Chi-Ming
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supporting information
p. 1490 - 1498
(2017/07/11)
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- Facile Hydrogenolysis of C(sp3)–C(sp3) σ Bonds
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The modification of benzylic quaternary, tertiary, and secondary carbon centers through palladium-catalyzed hydrogenolysis of C(sp3)–C(sp3) σ bonds is presented. When benzyl Meldrum's acid derivatives bearing quaternary benzylic centers are treated under mild hydrogenolysis conditions – palladium on carbon and atmospheric pressure of hydrogen – aromatics substituted with tertiary benzylic centers and Meldrum's acid are obtained with good to excellent yield. Analogously, substrates containing tertiary or secondary benzylic centers yield aromatics substituted with secondary benzylic centers or toluene derivatives, respectively. Furthermore, this strategy is used for the high yielding synthesis of diarylmethanes. The scope of the reductive dealkylation reaction is explored and the limitations with respect to steric and electronic factors are determined. A mechanistic analysis of the reaction is described that consisted of deuterium labelling experiments and hydrogenolysis of enantioenriched derivatives. The investigation shows that the C(sp3)–C(sp3) σ bond-cleaving events occur through a hybrid SN1/SN2 mechanism, in which the palladium center displaces a carbon-based leaving group, namely Meldrum's acid, with inversion of configuration, followed by reductive elimination of palladium to furnish a C?H bond. (Figure presented.).
- Fillion, Eric,Beaton, Eric,Nguyen, Yen,Wilsily, Ashraf,Bondarenko, Ganna,Jacq, Jér?me
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supporting information
p. 3422 - 3434
(2016/11/13)
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- Investigations of luminescent behavior and intramolecular energy transfer mechanism of europium(III) complexes with fluorinated β-ketoester ligand
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A fluorinated β-ketoester ligand, ethyl-(2-fluorobenzoyl) acetate (EFBA) has been employed to synthesized new europium binary and ternary complexes with ancillary ligands neocuproine (neo), bathophenanthroline (batho), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy) in high yield by the solution precipitation method. The ligand (EFBA) and the synthesized complexes Eu(EFBA)3·(H2O)2 (C1), Eu(EFBA)3·neo (C2), Eu(EFBA)3·batho (C3), Eu(EFBA)3·phen (C4), Eu(EFBA)3·bipy (C5) were characterized by elemental analysis, 1H NMR, IR, UV-vis, thermal analysis (TG/DTG) and luminescence spectroscopy. The thermal analysis results show that the complex is stable up to 231 °C temperature which is sufficient for the normal working of OLEDs. The luminescence measurements indicate that π electron rich organic ligand ethyl-(2-fluorobenzoyl) acetate possessing high absorption coefficient acts as a suitable chromophoric moiety for the transfer of energy to the central Eu3+ ion by the process of sensitization, this results in strong emissions band in red spectral region attributed to electric dipole 5D0 → 7F2 transition of europium ion. The luminescence intensity further enhanced by the introduction of N-containing ancillary ligands neocuproine, bathophenanthroline, 1,10-phenanthroline, and 2,2-bipyridyl in the ternary complexes C2-C5 because these ligands replace the solvent molecule in the coordination sphere and satisfy the coordination number around central europium ion. The sensitization process in europium complexes is investigated through the proposed energy transfer mechanism. The decay curves observations show the similar chemical environment around the europium ion in all the complexes.
- Devi, Rekha,Bala, Manju,Khatkar, S. P.,Taxak, V. B.,Boora, Priti
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- Discovery of novel AHLs as potent antiproliferative agents
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Three series of novel AHL analogs were synthesized and evaluated for their in vitro cytotoxic activity against four human cancer cell lines. The SARs investigation indicated that AHLs with a terminal phenyl group, especially those with the chalcone scaffold had remarkably enhanced cytotoxicity than those with the hydrophobic side chains. Besides, some of these compounds were much more potent than 5-Fu and natural OdDHL. Through the detailed SARs discussions, we found that compounds 10a-k and 14 with the 4-amino chalcone scaffold showed excellent inhibition against all the tested cancer cell lines and were much more potent than 5-Fu and AHLs. Such scaffold may act as a template for further lead optimization. Compound 10i with a 3, 4, 5-trimethoxy group was the most potent one against all the tested cancer cell lines. Flow cytometry analysis indicated that analog 11e induced the cellular apoptosis and cell cycle arrest of MCF-7 cells at G2/M phase in a concentration-and time-dependent manner.
- Ren, Jing-Li,Zhang, Xu-Yao,Yu, Bin,Wang, Xi-Xin,Shao, Kun-Peng,Zhu, Xiao-Ge,Liu, Hong-Min
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p. 321 - 329
(2015/03/04)
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- An efficient synthesis of new khellactone-type compounds using potassium hydroxide as catalyst via one-pot, three-component reaction
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In the present work, three-component synthesis for novel khellactone-type compounds via the reaction of Meldrum's acid, aryl aldehydes and 5,7-dihydroxy benzopyrone derivatives was described. In this reaction 10-aryl substituted-9,10-dihydropyrano[2,3-h]benzopyrone-8-ones as new khellactone analogous in the presence of catalytic amount of potassium hydroxide as cheap and green basic catalyst were obtained in good to excellent yields under refluxing methanol.
- Karami,Eskandari,Khodabakhshi
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p. 631 - 637
(2014/05/20)
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- Synthesis and biological evaluation of novel 2-Arylalkylthio-5-iodine-6- substituted-benzyl-pyrimidine-4(3H)-ones as Potent HIV-1 Non-Nucleoside reverse transcriptase inhibitors
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A novel series of 2-arylalkylthio-5-iodine-6-substitutedbenzyl-pyrimidine- 4(3H)- ones (S-DABOs) 8a-x had been synthesized via an efficient method. Their biological activity against HIV virus and RT assay were evaluated. Some compounds, especially 8h, 8l and 8n, displayed promising activity against HIV-1 RT with IC50 values in a range of 0.41 μM to 0.71 iM, which were much better than that of nevirapine. Molecular modeling studies revealed that the binding mode would be affected via forming an additional hydrogen bond by incorporating an oxygen atom on the C-2 side chain. The biological activity was in accordance with the docking results.
- Zhang, Liang,Tang, Xiaowan,Cao, Yuanyuan,Wu, Shaotong,Zhang, Yu,Zhao, Jianxiong,Guo, Ying,Tian, Chao,Zhang, Zhili,Liu, Junyi,Wang, Xiaowei
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p. 7104 - 7121
(2014/07/08)
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- Direct synthesis of polysubstituted 2-aminothiophenes by Cu(ii)-catalyzed addition/oxidative cyclization of alkynoates with thioamides
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A facile and direct synthetic method was developed for the construction of structurally important 2-aminothiophenes in moderate to excellent yields (up to 91%), via Cu(ii)-catalyzed addition/oxidative cyclization of readily available thioamides with alkynoates under an air atmosphere. This journal is
- Ge, Li-Shi,Wang, Zheng-Lin,An, Xing-Lan,Luo, Xiaoyan,Deng, Wei-Ping
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supporting information
p. 8473 - 8479
(2014/12/10)
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- Glycosylation enhances the anti-migratory activities of isomalyngamide A analogs
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Three, new, fully synthetic glycosylated isomalyngamide A analogs 4-6 were prepared and evaluated for their anti-migratory activities in human breast cancer cells. The results of the study show that two glycosylated derivatives 4 and 5, containing mannose and galactose appendages, suppress metastatic events (e.g., migration, invasion and adhesion) in human breast adenocarcinoma MDA-MB-231 cells at "nontoxic" concentration levels. In contrast, derivative 6 that contains a lactose moiety, displays a less potent activity. The findings show that monosaccharide rather than disaccharide appendages to the isomalyngamide A backbone more greatly influence cell migration and invasive ability. Evidence has been gained for a mechanism for inhibition of metastatic activities in MDA-MB-231 cells by 4 and 5, involving inactivation of the expression of p-FAK and paxillin through the integrin-mediated antimetastatic pathway.
- More, Shivaji V.,Chang, Tzu Ting,Chiao, Yu-Pin,Jao, Shu-Chuan,Lu, Chung-Kuang,Li, Wen-Shan
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supporting information
p. 169 - 178
(2013/07/27)
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- NOVEL CATIONIC LIPIDS AND METHODS OF USE THEREOF
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The present invention provides compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel cationic lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of a specific target protein at relatively low doses. In addition, the compositions and methods of the present invention are less toxic and provide a greater therapeutic index compared to compositions and methods previously known in the art.
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Paragraph 0415; 0416
(2013/03/28)
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- Novel nitenpyram analogues with tetrahydropyridone-fixed cis-configuration: Synthesis, insecticidal activities, and molecular docking studies
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To make further researches on the diversity of nitenpyram analogues with a cis-nitromethylene configuration, a series of cis-nitenpyram analogues (3a-q) with tetrahydropyridone-fixed cis-configuration were designed and synthesized. Preliminary bioassays showed that most of the designed nitenpyram analogues exhibited good insecticidal activity at 100 mg/L against Nilaparvata lugens and Myzus persicae, while analogues 3n afforded the best in vitro activity. Modeling the ligand-receptor complexes by molecular docking study revealed the analogues 3 with various substituents on phenyl show their different binding affinities to the insect nAChR, which also explained the structure-activity relationships observed in vitro. The Japan Institute of Heterocyclic Chemistry.
- Sun, Chuan-Wen,Wang, Jing,Wu, Ying,Nan, Shi-Bin,Zhang, Wang-Geng
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p. 1865 - 1880
(2013/10/22)
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- Novel fluorescent risedronates: Synthesis, photodynamic inactivation and imaging of Bacillus subtilis
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Novel fluorescently-labeled conjugates of risedronate were synthesized using an epoxide linker, enabling conjugation of risedronate via its pyridyl nitrogen with the aromatic succinimidyl esters. The compounds were characterized by using 1H NMR, 13C NMR, 31P NMR, UV-vis and fluorescence emission spectroscopies. Biological activity assays showed that the conjugates 14 and 15 exhibited photodynamic inactivation of Bacillus subtilis (ATCC 6633) with 91% and 47% bacterial lethality at 10 μM upon visible light irradiation, respectively. Both 14 and 15 could be also used for fluorescence imaging of Bacillus subtilis.
- Zhou, Li-Sheng,Yang, Ke-Wu,Feng, Lei,Xiao, Jian-Min,Liu, Cheng-Cheng,Zhang, Yi-Lin,Crowder, Michael W.
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supporting information
p. 949 - 954
(2013/03/14)
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- Novel fluorescent cephalosporins: Synthesis, antimicrobial activity and photodynamic inactivation of antibiotic resistant bacteria
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Two novel fluorescent cephalosporins, TCA and TBCA, were synthesized and characterized by 1H NMR, 13C NMR, UV-vis, and fluorescence spectroscopies. Biological activity assays demonstrated that TCA inactivated a Klebsiella pneumonia strain that expressed extended-spectrum β-lactamases. Incubation of 6 μM TCA with K. pneumonia cultures resulted in cell death for 84% of the cells after 126 J/cm2 of light irradiation. In vitro, TCA exhibited a MIC = 0.5 μg/mL with Staphylococcus aureus. Kinetic evaluation revealed that TCA and TBCA were substrates for B1 and B3 subclass metallo-β-lactamases. TBCA exhibited stronger binding affinities to the Gram-positive bacterial strains MRSA1, MRSA2, and S. aureus with value of 2.95-6.59 μM per 108 cells/mL.
- Xiao, Jian-Min,Feng, Lei,Zhou, Li-Sheng,Gao, Hui-Zhou,Zhang, Yi-Lin,Yang, Ke-Wu
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p. 150 - 159
(2013/03/13)
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- A novel fluorogenic substrate for dinuclear Zn(II)-containing metallo-β-lactamases
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In an effort to prepare a fluorogenic substrate to be used in activity assays with metallo-β-lactamases, (6R,7R)-8-oxo-7-(2-oxo-2H-chromene-3- carboxamido)-3-((4-(2-oxo-2H-chromene-3-carboxamido)-phenylthio)methyl) -5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (CA) was synthesized and characterized. CA exhibited a fluorescence quantum yield (φ) of 0.0059, two fluorescence lifetimes of 3.63 × 10-10 and 5.38 × 10 -9 s, and fluorescence intensity that is concentration-dependent. Steady-state kinetic assays revealed that CA is a substrate for metallo-β-lactamases (MβLs) L1 and CcrA, exhibiting Km and kcat values of 18 μM and 5 s-1 and 11 μM and 17 s-1, respectively.
- Zhang, Yin-Lin,Xiao, Jian-Min,Feng, Ji-Li,Yang, Ke-Wu,Feng, Lei,Zhou, Li-Sheng,Crowder, Michael W.
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supporting information
p. 1676 - 1679
(2013/04/10)
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- Synthesis, characterization and biological activity of some new carbostyril bearing 1H-pyrazole moiety
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In this study, 16 new 4-pyrazolyl-N-arylquinoline-2,5-dione 4 have been synthesized by the multicomponent reaction of pyrazole-4-carbaldehyde 1, Meldrum's acid 2 and 3-aryl-5,5-disubstitutedcyclohex-2-enone 3. The structures of compounds 4 were established by the combined use of 1HNMR, 13C NMR, FT-IR and mass spectra. All the 16 compounds were tested in vitro for their bacterial and fungal activity against a list of human pathogens, namely, Bacillus subtilis, Clostridium tetani, Streptococcus pneumoniae, Salmonella typhi, Vibrio cholerae, Escherichia coli, Aspergillus fumigatus and Candida albicans, using broth microdilution MIC (minimum inhibitory concentration) method. Some of the compounds were found to be the most effective analogs against the tested bacterial and fungal strains. Springer Science+Business Media, LLC 2011.
- Thumar, Nilesh J.,Patel, Manish P.
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p. 1751 - 1761
(2012/11/13)
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- One-pot, three component approach to synthesis of multipart fused heterocyclic compounds: Synthesis of fused pyran-2-ones
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An efficient, three-component synthesis of novel class of dihydropyran-2-ones which are fused with coumarin rings, from reaction between Meldrum's acid, aryl aldehydes and 5,7-dihydroxy-4-methyl (and phenyl) coumarin was described. In this research 9,10-dihydropyrano[2,3-h]benzopyrone-8-ones in the presence of catalytic amount of piperidine as organo basic catalyst were obtained in good to excellent yields under refluxing methanol for the time.
- Karami, Bahador,Eskandari, Khalil,Khodabakhshi, Saeed
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p. 76 - 84,9
(2020/09/02)
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- Methyl caffeate as an α-glucosidase inhibitor from solanum torvum fruits and the activity of related compounds
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In screening experiments for rat intestinal α-glucosidase (sucrase and maltase) inhibitors in 325 plants cultivated in Japan's southern island, of Tanegashima, marked inhibition against both sucrase and maltase was found in the extract of the fruit of Solanum torvum. Enzyme-assay guided fractionation of the extract led to the isolation of methyl caffeate (1) as a rat intestinal sucrase and maltase inhibitor. We examined 13 caffeoyl derivatives for sucrase- and maltase-inhibitory activities. The results showed that methyl caffeate (1) had a most favorable structure for both sucrase and maltase inhibition, except for a higher activity of methyl 3,4,5-trihydroxycinnamate (14) against sucrase. Its moderate inhibitory action against α-glucosidase provides a prospect for antidiabetic usage of S. torvum fruit.
- Takahashi, Keisuke,Yoshioka, Yasuyuki,Kato, Eisuke,Katsuki, Shigeki,Iida, Osamu,Hosokawa, Keizo,Kawabata, Jun
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experimental part
p. 741 - 745
(2011/07/08)
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- Facile and efficient aromatization of 1,4-dihydropyridines with M(NO 3)2·XH2O, TNCB, TBAP and HMTAI and preparation of deuterium labeled dehydronifedipine from nifedipine-d3
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The easy and efficient aromatization of various 1,4-dihydropyridines was investigated using various metal nitrates, trinitratocerium(IV) bromate (TNCB), and tetrabutyl ammonium periodate (TBAP) as oxidant in acetic acid at 100 °C, as well as hexamethylenetetramine-iodine (HMTAI) reflux in methanol. The efficient conversion of nifedipine-d3 to dehydronifedipine-d 3 as an internal standard can be used in the measurement of nifedipine concentration in a body.
- Shaikh, Ajam C.,Chen, Chinpiao
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supporting information; experimental part
p. 3664 - 3668
(2010/09/04)
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- Chemical library and structure-activity relationships of 11-demethyl-12-oxo calanolide A analogues as anti-HIV-1 agents
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(+)-Calanolide A (1) as a natural product was previously found as an inhibitor of HIV-1 reverse transcriptase. In our further investigation of its template, racemic 11-demethyl-12-oxo calanolide A (15), which had two fewer chiral carbon centers at the C-11 and C-12 positions than (+)-calanolide A, had a comparably inhibitory activity and better therapeutic index (EC50 = 0.11 μM, TI = 818) against HIV-1 in vitro. A library based on its structural core was then designed and synthesized with introduction of nine diversity points in this article. The evaluations of anti-HIV-1 activity in vitro concluded their structure-activity relationships (SARs). A novel compound (10-bromomethyl-11-demethyl-12-oxo calanolide A, 123) was identified to have much higher inhibitory potency and therapeutic index (EC50 = 2.85 nM, TI > 10,526) than those of the class compound against HIV-1. This finding provided a very important clue that modifications of the C ring at the C-10 position may be conducted to obtain drug candidates with better activity against HIV-1.
- Ma, Tao,Liu, Li,Xue, Hai,Li, Li,Han, Chunyan,Wang, Lin,Chen, Zhiwei,Liu, Gang
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p. 1432 - 1446
(2008/12/22)
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- Chemistry of diazocarbonyl compounds: XXV. Comparative photochemistry of diazo compounds and sulfur ylides of the 1,3-dioxane-4,6-dione series
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Photochemical decomposition of 2,2-dialkyl-5-diazo-1,3-dioxane-4,6-diones in the presence of pyridine, methanol, or dimethyl sulfide as carbene traps involves mainly the Wolff rearrangement which is likely to follow a concerted pattern, while the yield of the "carbene" products does not exceed 27-28%. No carbene intermediates are formed in the photolysis of the corresponding dioxo sulfonium ylides under analogous conditions, and the main photochemical process is 1,2-methyl shift (Stevens rearrangement), followed by photochemical transformations of the primary products according to the Norrish type II pattern. Pleiades Publishing, Inc., 2006.
- Nikolaev,Shevchenko,Platz,Khimich
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p. 815 - 827
(2007/10/03)
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- Wavelength-dependent photochemistry of diazo Meldrum's acid and its spirocyclic isomer, diazirino Meldrum's acid: Wolff rearrangement versus isomerization
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Photoreaction of diazo Meldrum's acid (1) shows a unique wavelength selectivity. At 254 nm it results in efficient (φ254 = 0.34) Wolff rearrangement, while irradiation with 355 nm light leads to a completely different process, isomerization into corresponding cyclic α,α″-dicarbonyl diazirine 2 (φ350 = 0.024). UV photolysis of diazirine 2 is accompanied by two competing processes: loss of nitrogen followed by the Wolff rearrangement and isomerization into diazo compound 1. Thermal decomposition of 1 leads to clean Wolff rearrangement, while heating of 2 causes quantitative conversion into diazo isomer 1. Copyright
- Bogdanova, Aneta,Popik, Vladimir V.
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p. 1456 - 1457
(2007/10/03)
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- Saccharin derivatives
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Saccharin derivatives of the formula I STR1 where the substituents have the following meanings: L and M are hydrogen, C1 -C4 -alkyl, C1 -C4 -alkoxy, C1 -C4 -alkylthio, chlorine, cyano, methylsulfonyl, nitro or trifluoromethyl; Z is hydrogen, C1 -C4 -alkyl, C3 -C8 -cycloalkyl, C3 -C6 -alkenyl, C3 -C5 -alkynyl, C1 -C4 -acyl, benzyl or phenyl, the phenyl rings in each case being unsubstituted or substituted by halogen or C1 -C4 -alkyl; Q is a radical T-J, where T is a carbonyl radical CO or the radical --CHY, J is a 4-linked isoxazole ring of the formula II STR2 where R1 is hydrogen or C1 -C4 -alkyl and R2 is C1 -C4 -alkyl, cyclopropyl, 1-methylcyclopropyl or 1-methylthiocyclopropyl; Y is an OH group, a hydroxyl group which may be acylated by C2 -C4 -acyl or a chlorine atom; and agriculturally customary salts of the compounds I are described.
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- Process for the preparation of 1,3-dioxane-4,6-dione derivates
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The invention relates to a process for preparing the compounds of general formula (I), wherein Rmeans hydrogen, C1 4alkyl or (C1 5alkoxy)carbonyl group; R1stands for a C1 6 alkyl, (C1 5alkyl)carbonyl, (C1 5alkoxy)carbonyl or (C1 5alkoxy)carbonyl-(C1 4alkyl) group; or a cyclohexyl group; or a cyclopentyl group; or a phenyl, furyl or thienyl group, optionally substituted, or a b-CH=CH group, wherein b is a phenyl group; or R and R1together form a C4 5alkylene group; R2represents a C1 5alkyl or phenyl group; R3means hydrogen or a C1 4alkyl group; or R2 and R3together form a pentylene group. By reacting a compound of general formula (II) with a compound of general formula (III) and/or reducing a compound of the general formula (IV),
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- ADDITION REACTION OF PHOTOENOLS FROM o-METHYL-SUBSTITUTED AROMATIC KETONES WITH 5-ALKYLIDENE-1,3-DIOXANE-4,6-DIONE DERIVATIVES
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Photolyses of 2-methylacetophenone or 2-phenylbenzophenone with isobutylidene Meldrum's acid or isobutylidene-1,3-dioxane-4,6-dione derivatives produced novel adducts, bonding between the β-carbon of the acylals and the 2-methyl carbon of the aromatic ketones.However, the photoenol derived from benzocyclobutenols by thermolysis dit not undergo the addition reaction with the acylal.The benzocyclobutenols reacted with isobutenylketene derived by pyrolysis of isobutylidene Meldrum's acid to yield corresponding benzocyclobutenyl 4-methyl-3-pentenoate derivatives.
- Tsuno, Takaski,Sugiyama, Kunio
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p. 859 - 876
(2007/10/02)
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- Inhibitors of the advanced glycosylation of proteins and methods of use therefor
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The present invention relates to compositions and methods for inhibiting nonenzymatic cross-linking (protein aging). Accordingly, a composition is disclosed which comprises an agent capable of inhibiting the formation of advanced glycosylation endproducts of target proteins by reacting with a carbonyl moiety of an early glycosylation product of such target proteins resulting from their initial glycosylation. The method comprises contacting the target protein with the composition. Both industrial and therapeutic applications for the invention are envisioned, as food spoilage and animal protein aging can be treated.
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- The synthesis of β-keto lactones via cyclization of β-keto ester dianions or the cyclization of Meldrum's acid derivatives
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Two new methods to synthesize macrocyclic β-keto lactones have been developed.The first involves the synthesis of ω-halo-β-keto esters and an intramolecular alkylation of the dianions to these compounds.The reaction is complicated by elimination in the small and medium ring systems and by difficulties in purifying the final products.However, it is possible to obtain modest yields of the desired β-keto lactones.This procedure was used to synthesize the 25- and 27-membered ring β-hydroxy lactones that are the constituents of termite defense compounds.The second method involves the thermolysis of acylated Meldrum's acid derivatives, which leads directly to β-keto lactones.This process gives modest yields of macrocyclic systems and good yield of the unsubstituted 3-oxopentan-5-olide (25) .The 14-membered macrocyclic β-keto lactone 9j has a complex 1H NMR spectrum, which has been interpreted in terms of multiple conformations.The temperature dependence of the NMR spectrum of 9j is consistent with entropic, rather than enthalpic, control of the equilibrium.Quasiharmonic entropy calculations are consistent with this model.
- Lermer, Leonard,Neeland, Edward G.,Ounsworth, James P.,Sims, Russell J.,Tischler, Samuel A.,Weiler, Larry
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p. 1427 - 1445
(2007/10/02)
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- Process for the preparation of Meldrum's acid
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A process for producing Meldrum's acid in excellent yield wherein acetic anhydride is added in a slow, controlled manner to a mixture of acetone, malonic acid and an acid catalyst.
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- Novel β-lactam acetic acid derivatives
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New β-lactam acetic acid derivatives I STR1 wherein R represents alkyl, alkyl substituted with amino, protected amino, mono- or di-alkylamino, hydroxy, protected hydroxy or alkoxy, and alkenyl, and their salts are useful as intermediates for preparing 1-azabicyclo [3.2.0]hept-2-ene antibiotics II STR2 The process for preparing the β-lactam acetic acid derivatives I as well as the overall process which starting from the acids I leads to the antibiotics II are also claimed.
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- PHOTOLYSIS OF 5-DIAZO-2,2-DIMETHYL-4,6-DIOXO-1,3-DIOXANE (DIAZOISOPROPYLIDENEMALONIC ACID)
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The principal pathway in the photochemical (λ > 210 nm) transformation of 5-diazo-2,2-dimethyl-4,6-dioxo-1,3-dioxane in an aqueous medium (or in methanol) is splitting out of nitrogen and the Wolff rearrangement to give the stable 2,2-dimethyl-5-oxo-1,3-dioxolane-4-carboxylic acid (or its methyl ester), which undergoes decarboxylation only at temperature above 150 deg C, whereas it undergoes hydrolysis to a hydroxymalonic acid in the presence of trifluoroacetic acid.
- Nikolaev, V. A.,Khimich, N. N.,Korobitsyna, I. K.
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p. 264 - 268
(2007/10/02)
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- PORPHYRINS. 18. SYNTHESIS OF OCTAPROPYLPORPHYRIN BY THE METHOD OF MONOPYRROLE CYCLOTETRAMERIZATION OF 5-CARBOXY-2-METHOXYMETHYL-3,4-DIPROPYLPYRROLE. INVESTIGATION OF THE THERMOLYSIS OF meso-N-METHYLFORMALDIMINEOCTAPROPYLPORPHYRIN
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The synthesis of octapropylporphyrin on the basis of 5-carboxy-2-methoxymethyl-3,4-dipropylpyrrole was realized.It was demonstrated that in the thermolysis of meso-N-methylformaldimineoctapropylporphyrin, 31,51-cyclo-31-ethylidene- and 31,51-cyclo-31-ethyl-51-(N-methylimine) derivatives are also formed in addition to 31,51-cyclo-31-ethylheptapropylporphyrin.
- Shul'ga, A. M.,Ponomarev, G. V.
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p. 748 - 753
(2007/10/02)
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- Nucleophilic Addition to Olefins. 2. Reaction of Benzylidene Meldrum's Acid with Water, Hydroxide Ion, and Aryloxide Ions. Complete Kinetic Analysis of the Hydrolytic Cleavage of the C=C Double Bond
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The kinetics of reversible nucleophilic attack by water, hydroxide ion, phenoxide ion, and p-bromophenoxide ion on benzylidene Meldrum's acid was measured in aqueous solution by the stopped-flow method.The rate of protonation on carbon of the anionic addition complex between benzylidene Meldrum's acid and hydroxide ion was also measured.The combination of our results with literature data on the rate of hydrolytic cleavage of benzylidene Meldrum's acid allowed us to map out a detailed mechanism of the cleavage reaction and assign rate-limiting step in different pH ranges.At high pH, protonation on carbon of the anionic addition complex is rate limiting; at low pH, deprotonation of the OH group in the neutral addition complex is rate limiting, which implies a rate constant for the breakdown of the tetrahedral intermediate by carbanion departure on the order of, and probably exceeding, 1010 s-1.
- Bernasconi, Claude F.,Leonarduzzi, Gianni D.
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p. 1361 - 1366
(2007/10/02)
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