- Palladium Loaded Dendronized Polymer as Efficient Polymeric Sustainable Catalyst for Heck Coupling Reaction
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The palladium incorporated amine-functionalized dendronized polymer was synthesized by the addition of palladium acetate to dendronized polymer in methanol at room temperature. Palladium species are immobilized onto the dendritic structure by their coordination with amino functional groups. The newly developed dendritic system showed high palladium content in the low generation level itself, which was found to be 4.19?mmol/g. This was fairly higher than, the other palladium-based catalysts. Energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, UV–Visible spectroscopy, and X-ray photoelectron spectroscopy were used to confirm the successful synthesis of the new catalyst. It was used as a homogeneous palladium catalyst for Heck coupling reaction between olefins and differently substituted aryl halides and the products were isolated in high yield. The products isolated were in trans configuration, which indicated the selectivity of the newly developed catalytic system. Also, this catalyst system was reused up to nine times without a significant decrease in its catalytic activity. The easy accessibility of catalytic sites, stability, resistance to metal leaching, high catalytic activity and remarkable stereoselectivity with a low amount of catalyst are all due to the dendritic support. The docking study was carried out for all the stilbene derivatives obtained by the Heck coupling reaction against DprE1 protein to study its potential antitubercular activity. All the compounds displayed superior docking score values over the range ??6.5 to ??8.2?kcal/mol, compared to the standard drug isoniazid with docking score of ??6.1?kcal/mol against DprE1. Graphic Abstract: [Figure not available: see fulltext.]
- Hiba, K.,Krishna, G. Anjali,Prathapan, S.,Sreekumar, K.
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- Larvicidal activity and in silico studies of cinnamic acid derivatives against Aedes aegypti (Diptera: Culicidae)
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Cinnamic acid derivatives (CAD's) represent a great alternative in the search for insecticides against Aedes aegypti mosquitoes since they have antimicrobial and insecticide properties. Ae. aegypti is responsible for transmitting Dengue, Chikungunya, and Zika viruses, among other arboviruses associated with morbimortality, especially in developing countries. In view of this, in vitro analyses of n-substituted cinnamic acids and esters were performed upon 4th instar larvae (L4) of Ae. aegypti, as well as, molecular docking studies to propose a potential biological target towards this mosquitoes species. The larvicide assays proved that n-substituted ethyl cinnamates showed a more pronounced activity than their corresponding acids, in which p-chlorocinnamate (3j) presented a LC50 value of 8.3 μg/mL. Thusly, external morphologic alterations (rigid and elongated body, curved bowel, and translucent or darkened anal papillae) of mosquitoes’ group exposed to compound 3j, were observed by microscopy. In addition, an analytical method was developed for the quantification of the most promising analog by using high-performance liquid chromatography with UV detection (HPLC-UV). Molecular docking studies suggested that the larvicide action is associated with inhibition of acetylcholinesterase (AChE) enzyme. Therefore, expanding the larvicidal study with the cinnamic acid derivatives against the vector Ae. aegypti is important for finding search for more effective larvicides and with lower toxicity, since they have already shown good larvicidal properties against Ae. aegypti.
- Bezerra Fran?a, Saraliny,Carine Barros de Lima, Luana,Ester de Sá Barreto Barros, Maria,Ferreira da Silva-Júnior, Edeildo,José da Paz Lima, Dimas,Rychard da Silva Cunha, Cristhyan,Santos Anuncia??o, Daniela
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- Quorum sensing and nf-κb inhibition of synthetic coumaperine derivatives from piper nigrum
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Bacterial communication, termed Quorum Sensing (QS), is a promising target for virulence attenuation and the treatment of bacterial infections. Infections cause inflammation, a process regulated by a number of cellular factors, including the transcription Nuclear Factor kappa B (NF-κB); this factor is found to be upregulated in many inflammatory diseases, including those induced by bacterial infection. In this study, we tested 32 synthetic derivatives of coumaperine (CP), a known natural compound found in pepper (Piper nigrum), for Quorum Sensing Inhibition (QSI) and NF-κB inhibitory activities. Of the compounds tested, seven were found to have high QSI activity, three inhibited bacterial growth and five inhibited NF-κB. In addition, some of the CP compounds were active in more than one test. For example, compounds CP-286, CP-215 and CP-158 were not cytotoxic, inhibited NF-κB activation and QS but did not show antibacterial activity. CP-154 inhibited QS, decreased NF-κB activation and inhibited bacterial growth. Our results indicate that these synthetic molecules may provide a basis for further development of novel therapeutic agents against bacterial infections.
- Baruch, Yifat,Gopas, Jacob,Kadosh, Yael,Kumar, Rajendran Saravana,Kushmaro, Ariel,Muthuraman, Subramani,Yaniv, Karin
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supporting information
(2021/05/28)
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- Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure
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Flavinium salts are frequently used in organocatalysis but their application in photoredox catalysis has not been systematically investigated to date. We synthesized a series of 5-ethyl-1,3-dimethylalloxazinium salts with different substituents in the positions 7 and 8 and investigated their application in light-dependent oxidative cycloelimination of cyclobutanes. Detailed mechanistic investigations with a coumarin dimer as a model substrate reveal that the reaction preferentially occurs via the triplet-born radical pair after electron transfer from the substrate to the triplet state of an alloxazinium salt. The very photostable 7,8-dimethoxy derivative is a superior catalyst with a sufficiently high oxidation power (E=2.26 V) allowing the conversion of various cyclobutanes (with Eox up to 2.05 V) in high yields. Even compounds such as all-trans dimethyl 3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylate can be converted, whose opening requires a high activation energy due to a missing pre-activation caused by bulky adjacent substituents in cis-position.
- Hartman, Tomá?,Reisnerová, Martina,Chudoba, Josef,Svobodová, Eva,Archipowa, Nataliya,Kutta, Roger Jan,Cibulka, Radek
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p. 373 - 386
(2021/02/01)
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- Iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabled aldehyde C-H methylation
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A practical and general iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabling aldehyde C-H methylation for the synthesis of methyl ketones has been developed. This mild, operationally simple method uses ambient air as the sole oxidant and tolerates sensitive functional groups for the late-stage functionalization of complex natural-product-derived and polyfunctionalized molecules.
- Gong, Pei-Xue,Xu, Fangning,Cheng, Lu,Gong, Xu,Zhang, Jie,Gu, Wei-Jin,Han, Wei
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supporting information
p. 5905 - 5908
(2021/06/18)
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- Piperlongumine analogs promote A549 cell apoptosis through enhancing ROS generation
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Chemotherapeutic agents, which contain the Michael acceptor, are potent anticancer molecules by promoting intracellular reactive oxygen species (ROS) generation. In this study, we synthesized a panel of PL (piperlongumine) analogs with chlorine attaching at C2 and an electronwithdrawing/electron-donating group attaching to the aromatic ring. The results displayed that the strong electrophilicity group at the C2–C3 double bond of PL analogs plays an important role in the cytotoxicity whereas the electric effect of substituents, which attached to the aromatic ring, partly contributed to the anticancer activity. Moreover, the protein containing sulfydryl or seleno, such as TrxR, could be irreversibly inhibited by the C2–C3 double bond of PL analogs, and boost intracellular ROS generation. Then, the ROS accumulation could disrupt the redox balance, induce lipid peroxidation, lead to the loss of MMP (Mitochondrial Membrane Potential), and ultimately result in cell cycle arrest and A549 cell line death. In conclusion, PL analogs could induce in vitro cancer apoptosis through the inhibition of TrxR and ROS accumulation.
- Li, Peng-Xiao,Li, Yan-Mo,Liu, Guo-Yun,Liu, Ren-Min,Mu, Wen-Wen,Sun, Ai-Ling,Sun, Ya-Lei,Yang, Jie
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- Identification of novel functionalized carbohydrazonamides designed as chagas disease drug candidates
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Background: Although several research efforts have been made worldwide to discover novel drug candidates for the treatment of Chagas disease, the nitroimidazole drug benznidazol remains the only therapeutic alternative in the control of this disease. However, this drug presents reduced efficacy in the chronic form of the disease and limited safety after long periods of admini-stration, making it necessary to search for new, more potent and safe prototypes. Objective: We described herein the synthesis and the trypanocidalaction of new functionalized carbohydrazonamides (2-10) against trypomastigote forms of Trypanosoma cruzi. Methods: These compounds were designed through the application of molecular hybridization concept between two potent anti-T. cruzi prototypes, the nitroimidazole derivative megazol (1) and the cinnamyl N-acylhydrazone derivative (14) which have been shown to be twice as potent in vitro as benznidazole. Results: The most active compounds were the (Z)-N'-((E)-3-(4-nitrophenyl)-acryloyl)-1-methyl-5-nitro-1H-imidazol-2-carbohydrazonamide (6) (IC50 =9.50 μM) and the (Z)-N'-((E)-3-(4-hydroxyphe-nyl)-acryloyl)-1-methyl-5-nitro-1H-imidazol-2-carbohydrazonamide (8) (IC50 =12.85 μM), which were almost equipotent to benznidazole (IC50 =10.26 μM) used as standard drug. The removal of the amine group attached to the imine subunit in the corresponding N-acylhydrazone derivatives (11-13) resulted in less potent or inactive compounds. The para-hydroxyphenyl derivative (8) presented also a good selectivity index (SI = 32.94) when tested against mammalian cells from Swiss mice. Conclusion: The promising trypanocidal profile of new carbohydrazonamide derivatives (6) and (8) was characterized. These compounds have proved to be a good starting point for the design of more effective trypanocidal drug candidates.
- Do Nascimento, Mayara S. S.,Camara, Vitória R. F.,da Costa, Juliana S.,Barbosa, Juliana M. C.,Lins, Alessandra S. M.,Salom?o, Kelly,de Castro, Solange L.,Carvalho, Samir A.,da Silva, Edson F.,Fraga, Carlos A. M.
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p. 774 - 783
(2020/08/19)
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- A new class of 1,3,5-triazine-based selective estrogen receptor degraders (SERDs): Lead optimization, molecular docking and dynamic simulation
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Selective estrogen receptor degrader (SERD) that acts as not only ER antagonist, but also ER degrader, would be useful for the treatment for drug-resistance ER+ breast cancer. However, most of currently available SERD candidates involve very limited molecular scaffolds and are still in clinical trials. In this study, we introduced a 1,3,5-triazine ring into a homobibenzyl motif extracted from amounts of ER ligands and synthesized sixteen SERDs bearing acrylic acid or acrylic amide side chains that possess both ERα antagonism and degradation properties. And all compounds were screened for their anti-proliferative activity against ER+ MCF-7 and Ishikawa cell lines. Among them, compound XHA1614 displayed potent growth inhibition activity against MCF-7 and Ishikawa cells with IC50 values of 3.15 μM and 3.11 μM, respectively. Moreover, XHA1614 could dramatically degrade ER level at 1 nM in a Western blotting assay and afforded an outstanding antagonistic activity via suppressing the expression of progesterone receptor messenger RNA in MCF-7 cells in a RT-PCR assay. Further molecular docking and dynamic simulation on properly selected derivative furnished insights into its binding profile within ERα. Our findings suggest that the 1,3,5-triazine core was a feasible alternative to currently reported SERD scaffold, and provide information that will be useful for further development of promising SERDs candidates for breast cancer therapies.
- Huang, Ali,Lu, Xiang,Luo, Guoshun,Mao, Jiashun,Sun, Liang,Xiang, Hua,Xiao, Maoxu
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- Bioassay of ferulic acid derivatives as influenza neuraminidase inhibitors
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Four series of ferulic acid derivatives were designed, synthesized, and evaluated for their neuraminidase (NA) inhibitory activities against influenza virus H1N1 in vitro. The pharmacological results showed that the majority of the target compounds exhibited moderate influenza NA inhibitory activity, which was also better than that of ferulic acid. The two most potent compounds were 1m and 4a with IC50 values of 12.77 ± 0.47 and 12.96 ± 1.34 μg/ml, respectively. On the basis of the biological results, a preliminary structure–activity relationship (SAR) was derived and discussed. Besides, molecular docking was performed to study the possible interactions of compounds 1p, 2d, 3b, and 4a with the active site of NA. It was found that the 4-OH-3-OMe group and the amide group (CON) of ferulic acid amide derivatives were two key pharmacophores for NA inhibitory activity. It is meaningful to further modify the natural product ferulic acid to improve its influenza NA inhibitory activity.
- Cui, Man-Ying,Xiao, Meng-Wu,Xu, Lv-Jie,Chen, Yun,Liu, Ai-Lin,Ye, Jiao,Hu, Ai-Xi
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- Design, synthesis, and evaluation of novel cinnamic acid-tryptamine hybrid for inhibition of acetylcholinesterase and butyrylcholinesterase
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Background: Acetylcholine deficiencies in hippocampus and cortex, aggregation of β-amyloid, and β-secretase over activity have been introduced as main reasons in pathogenesis of Alzheimer’s disease. Methods: Colorimetric Ellman’s method was used for determination of IC50 value in AChE and BChE inhibitory activity. The kinetic studies, neuroprotective and β-secretase inhibitory activities, evaluation of inhibitory potency on β-amyloid (Aβ) aggregations induced by AChE, and docking study were performed for prediction of the mechanism of action. Result and discussion: A new series of cinnamic acids-tryptamine hybrid was designed, synthesized, and evaluated as dual cholinesterase inhibitors. These compounds demonstrated in-vitro inhibitory activities against acetyl cholinesterase (AChE) and butyryl cholinesterase (BChE). Among of these synthesized compounds, (E)-N-(2-(1H-indol-3-yl)ethyl)-3-(3,4-dimethoxyphenyl)acrylamide (5q) demonstrated the most potent AChE inhibitory activity (IC50 = 11.51?μM) and (E)-N-(2-(1H-indol-3-yl)ethyl)-3-(2-chlorophenyl)acrylamide (5b) were the best anti-BChE (IC50 = 1.95?μM) compounds. In addition, the molecular modeling and kinetic studies depicted 5q and 5b were mixed type inhibitor and bound with both the peripheral anionic site (PAS) and catalytic sites (CAS) of AChE and BChE. Moreover, compound 5q showed mild neuroprotective in PC12 cell line and weak β-secretase inhibitory activities. This compound also inhibited aggregation of β-amyloid (Aβ) in self-induced peptide aggregation test at concentration of 10?μM. Conclusion: It is worth noting that both the kinetic study and the molecular modeling of 5q and 5b depicted that these compounds simultaneously interacted with both the catalytic active site and the peripheral anionic site of AChE and BChE. These findings match with those resulted data from the enzyme inhibition assay. [Figure not available: see fulltext.]
- Ghafary, Shahrzad,Ghobadian, Roshanak,Mahdavi, Mohammad,Nadri, Hamid,Moradi, Alireza,Akbarzadeh, Tahmineh,Najafi, Zahra,Sharifzadeh, Mohammad,Edraki, Najmeh,Moghadam, Farshad Homayouni,Amini, Mohsen
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p. 463 - 477
(2020/05/25)
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- Oxime-derived palladacycle Immobilized in an Ionic Liquid Brush as an Efficient and Reusable Catalyst for Mozoroki-Heck Reaction in Neat Water
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An efficient and reusable heterogeneous catalyst with oxime-derived palladacycle immobilized in an ionic liquid brush has been synthesized and an environmentally-friendly procedure have been developed for coupling aryl iodides and bromides with acrylic acid. These reactions were conducted in neat water under aerobic conditions with water-insoluble or even solid aryl halides and they proceeded smoothly and cleanly without any organic co-solvent or other additives. The ionic liquid brush could be easily recovered and reused at least five times without significant loss of activity. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability.
- Wang, Rong,Li, Shan,Li, Jing,Wei, Junfa
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- Salen-porphyrin-based conjugated microporous polymer supported Pd nanoparticles: Highly efficient heterogeneous catalysts for aqueous C-C coupling reactions
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The salen-porphyrin based conjugated microporous polymer (SP-CMP) was first constructed by polycondensation reaction of a salen-dialdehyde derivative and pyrrole. Due to the outstanding chemical and thermal stability, abundant micropores with a reasonable pore size, and ordered salen-porphyrin arrays in the A4B4-type polymer framework, the functional CMP was further applied as a Pd nanoparticle support by the coordinate interactions between the polydentate chelating sites with Pd(OAc)2 and subsequent reduction with NaBH4. The as-synthesized composite material (Pd@SP-CMP) was fully characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and solid-state 13C nuclear magnetic resonance (NMR). The porous property of Pd@SP-CMP was also characterized by N2 adsorption/desorption isotherms and the obtained material exhibited a Brunauer-Emmett-Teller (BET) surface area of 266 m2 g-1, together with a pore volume of 0.192 cm3 g-1. The microscopic morphology of Pd@SP-CMP was further evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Pd@SP-CMP material with highly dispersed Pd nanoparticles exhibited excellent catalytic activity towards Suzuki-Miyaura and Heck-Mizoroki coupling reactions in water or in the dioxane/water mixture. In addition, Pd@SP-CMP also displayed outstanding stability and recyclability, and it can be reused without loss of activity in ten successive reactions. More importantly, the salen-porphyrin based CMPs could be the promising candidates for developing high-performance heterogeneous catalysts.
- Ju, Pengyao,Wu, Shujie,Su, Qing,Li, Xiaodong,Liu, Ziqian,Li, Guanghua,Wu, Qiaolin
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supporting information
p. 2660 - 2666
(2019/02/12)
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- On the azo dyes derived from benzoic and cinnamic acids used as photosensitizers in dye-sensitized solar cells
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In order to get a better insight into the relationship between molecular structure and photovoltaic performance, six monoazo dye molecules containing benzoic and cinnamic acid moieties were synthesized and their photovoltaic properties were studied. Three of them have not been previously used in solar cells. Spectroscopic measurements of the investigated compounds coupled with theoretical calculations were performed. Short-circuit current density, open-circuit voltage, and fill-factor were determined. It was found that a larger amount of short-circuit current density will be generated if the HOMO–LUMO energy gap is lower, determined by the stability of the molecule and the electronic effect of the donor moiety. Among both series of synthesized dye molecules, the highest obtained values of short-circuit current density were achieved with (2-hydroxynaphthalene-1-ylazo)benzoic acid and (2-hydroxynaphthalene-1-ylazo)cinnamic acid, and thus they were regarded as promising candidates for application in dye-sensitized solar cells.
- Matovi?, Luka,Tasi?, Nikola,Tri?ovi?, Nemanja,La?arevi?, Jelena,Vitnik, Vesna,Vitnik, ?eljko,Grgur, Branimir,Mijin, Du?an
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p. 1183 - 1203
(2019/09/10)
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- Mild, Metal-Free and Protection-Free Transamidation of N-Acyl-2-piperidones to Amino Acids, Amino Alcohols and Aliphatic Amines and Esterification of N-Acyl-2-piperidones
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Amides are indispensable building blocks of biological systems, pharmaceuticals, and materials. We report a highly selective method for the synthesis of amides via transamidation process. Transamidation of N-acyl-2-piperidones with a broad range of amines is demonstrated under exceedingly mild and metal-free reaction condition that relies on the amide bond twist to weaken the amidic resonance. Transamidation proceeds under the neat condition at room temperature, in short reaction times (30–90 min) with good yields. Considerable variation is tolerated with both amine and imide substrates. Of note, amines bearing carboxylic acids (glycine and serine) and hydroxyl groups (dopamine, tyramine, etc.) are well tolerated which are otherwise problematic under the metal-catalyzed protocol. Our current method is applicable for transamidation of both alkyl and aryl-N-acyl-2-piperidones. The practical value of the method is highlighted by the synthesis of four natural product amide alkaloids in high yields under mild reaction conditions. In the absence of nucleophilic amines, N-acyl-2-piperidones undergoes esterification with EtOH at elevated temperature. Single crystal X-ray analysis of an N-acyl-2-piperidone shows amide bond twist, τ = –20.39° and pyramidalization, χN = –11.73°. This weakens the amidic conjugation and might be the factor controlling the reactivity and selectivity of these imides. We envision that the N-acyl-2-piperidone scaffold would be useful in the synthesis of pharmaceuticals and materials.
- Subramani, Muthuraman,Rajendran, Saravana Kumar
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supporting information
p. 3677 - 3686
(2019/06/08)
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- 1,3,5-triazine compound or medicinal salt thereof as well as preparation method and application thereof
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The invention discloses a 1,3,5-triazine compound of a formula (I) or a formula (II) shown in the specification, or a medicinal salt thereof, and furthermore discloses a preparation method and application of the compound or the medicinal salt thereof. The compound or the medicinal salt thereof disclosed by the invention can be adopted to prepare medicines for treating human breast cancer and endometrial cancer.
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Paragraph 0081-0082
(2019/10/04)
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- Synthesis of cinnamic acid derivatives and leishmanicidal activity against Leishmania braziliensis
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Leishmania braziliensis is one of the pathogenic agents of cutaneous and mucocutanoeous leishmaniasis. There are no validated vaccines to prevent the infection and the treatment relies on drugs that often present severe side effects, which justify the efforts to find new potential antileishmanial drugs. An alternative to promote the discovery of new drugs would be the association of different chemical groups of bioactive compounds. Here we describe the synthesis and bioactivity evaluation against L. braziliensis of cinnamic acid derivatives possessing isobenzofuranone and 1,2,3-triazole functionalities. We tested 25 compounds at 10 μM concentration against extracellular promastigotes and intracellular amastigotes during macrophage infection. Most compounds were more active against amastigotes than to promastigotes. The derivatives (E)-3-oxo-1,3-dihydroisobenzofuran-5-yl-(3,4,5-trimethoxy) cinnamate (5c), (1-(3,4-difluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl cinnamate (9g), and (1-(2-bromobenzyl)-1H-1,2,3-triazol-4-yl)methyl cinnamate (9l) were the most effective presenting over 80% toxicity on L. braziliensis amastigotes. While compound 5c is a cinnamate with an isobenzofuranone portion, 9g and 9l are triazolic cinnamic acid derivatives. The action of these compounds was comparable to amphotericin B used as positive control. Ultrastructural analysis revealed that 5c-treated parasites showed impaired cytokinesis and apoptosis triggering. Taken together, these results highlight the potential of cinnamic acid derivatives in development of novel anti-leishmanial drugs.
- Rodrigues, Michelle Peixoto,Tomaz, Deborah Campos,?ngelo de Souza, Luciana,Onofre, Thiago Souza,Aquiles de Menezes, Wemerson,Almeida-Silva, Juliana,Suarez-Fontes, Ana Márcia,Rogéria de Almeida, Márcia,Manoel da Silva, Adalberto,Bressan, Gustavo Costa,Vannier-Santos, Marcos André,Rangel Fietto, Juliana Lopes,Teixeira, Róbson Ricardo
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- Synthesis and Hypoglycemic Activity of Aryl(Hetaryl)Propenoic Cyanopyrrolidine Amides
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Abstract: A series of amides based on (2S)-cyanopyrrolidine and α, β-unsaturated aryl- and hetarylcarboxylic acids have been synthesized. The dependence of the hypoglycemic activity of compounds on the structure of the aromatic fragment has been studied in the oral glucose tolerance test in mice. Amides based on (E)-3-phenylprop-2-enoic and (E)-3-(4-methoxyphenyl)prop-2-enoic acids and (2S)-cyanopyrrolidine have been shown to significantly reduce blood glucose levels in mice. The observed hypoglycemic effect at a dose of 10 mg/kg is comparable to the effect of hypoglycemic drug vildagliptin.
- Kuranov,Blokhin,Borisov,Khvostov,Luzina,Salakhutdinov
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p. 374 - 380
(2019/10/28)
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- A Highly Efficient NHC-Catalyzed Aerobic Oxidation of Aldehydes to Carboxylic Acids
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An N-heterocyclic carbene (NHC) organocatalytic aerobic oxidation of aldehydes to the corresponding carboxylic acids is explored. Remarkably, this method allows for efficient conversion of different classes of aldehydes including highly challenging electron-rich aryl aldehydes, ortho -substituted aryl aldehydes, various heteroaromatic aldehydes and α,β-unsaturated aldehydes under mild reaction conditions. These substrates, under previously reported NHC-catalyzed methods, are typically unreactive or give poor yields, require high reaction temperatures and reaction times of several days.
- Khatana, Anil Kumar,Singh, Vikram,Gupta, Manoj Kumar,Tiwari, Bhoopendra
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p. 4290 - 4294
(2018/11/23)
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- Synthesis and biological evaluation of phloroglucinol derivatives possessing α-glycosidase, acetylcholinesterase, butyrylcholinesterase, carbonic anhydrase inhibitory activity
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A series of novel phloroglucinol derivatives were designed, synthesized, characterized spectroscopically and tested for their inhibitory activity against selected metabolic enzymes, including α-glycosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase I and II (hCA I and II). These compounds displayed nanomolar inhibition levels and showed Ki values of 1.14–3.92 nM against AChE, 0.24–1.64 nM against BChE, 6.73–51.10 nM against α-glycosidase, 1.80–5.10 nM against hCA I, and 1.14–5.45 nM against hCA II.
- Burmaoglu, Serdar,Yilmaz, Ali O.,Taslimi, Parham,Algul, Oztekin,Kilic, Deryanur,Gulcin, Ilhami
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- Discovery of caffeic acid phenethyl ester derivatives as novel myeloid differentiation protein 2 inhibitors for treatment of acute lung injury
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Myeloid differentiation protein 2 (MD2) is an essential molecule which recognizes lipopolysaccharide (LPS), leading to initiation of inflammation through the activation of Toll-like receptor 4 (TLR4) signaling. Caffeic acid phenethyl ester (CAPE) from propolis of honeybee hives could interfere interactions between LPS and the TLR4/MD2 complex, and thereby has promising anti-inflammatory properties. In this study, we designed and synthesized 48 CAPE derivatives and evaluated their anti-inflammatory activities in mouse primary peritoneal macrophages (MPMs) activated by LPS. The most active compound, 10s, was found to bind with MD2 with high affinity, which prevented formation of the LPS/MD2/TLR4 complex. The binding mode of 10s revealed that the major interactions with MD2 were established via two key hydrogen bonds and hydrophobic interactions. Furthermore, 10s showed remarkable protective effects against LPS-caused ALI (acute lung injury) in vivo. Taken together, this work provides new lead structures and candidates as MD2 inhibitors for the development of anti-inflammatory drugs.
- Chen, Lingfeng,Jin, Yiyi,Chen, Hongjin,Sun, Chuchu,Fu, Weitao,Zheng, Lulu,Lu, Min,Chen, Pengqin,Chen, Gaozhi,Zhang, Yali,Liu, Zhiguo,Wang, Yi,Song, Zengqiang,Liang, Guang
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p. 361 - 375
(2017/12/07)
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- Visible-light-enabled denitrative carboxylation of β-nitrostyrenes: A direct photocatalytic approach to cinnamic acids
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The first workable application of β-nitrostyrenes and CBr4 as coupling partners for a highly stereoselective synthesis of (E)-cinnamic acids under visible light photoredox catalysis is reported. The reaction involves a radical denitrative tribromomethylation/hydrolysis cascade to afford (E)-cinnamic acids in excellent yields at room temperature in a one-pot procedure. Moreover, the implementation of visible light as a clean and inexpensive energy source and CBr4 as the latent source of carboxylic groups makes the protocol reconcilable with the present day scenario of organic synthesis.
- Tripathi, Shubhangi,Yadav, Lal Dhar S.
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supporting information
p. 3765 - 3769
(2018/03/06)
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- A silica-supported palladium-bis(oxazoline) complex efficiently catalyzes the synthesis of cinnamic acid derivatives via Mizoroki–Heck coupling reactions
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A palladium(II)-bis(oxazoline) complex supported on silica (Pd-BOX-Si) was prepared, characterized and applied as a catalyst in Mizoroki–Heck cross-coupling reactions. The bis(oxazoline) (BOX) ligand has a hydroxyl group that can be anchored to 4-benzyl chloride-functionalized silica gel, followed by the coordination of palladium(II) chloride. The catalytic activity and the recyclability of Pd-BOX-Si have been investigated in the production of cinnamic acid derivatives via Mizoroki–Heck coupling reactions of acrylates with aryl halides; The Pd-BOX-Si catalyst demonstrated excellent catalytic activity. Characterization of the recycled Pd-BOX-Si catalyst revealed its good stability under the reaction conditions employed.
- Ibrahim, Mansur B.,Suleiman, Rami,Fettouhi, Mohammed,El Ali, Bassam
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- Piperlongumine derived cyclic sulfonamides (sultams): Synthesis and in?vitro exploration for therapeutic potential against HeLa cancer cell lines
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A novel modification of piperlongumine is designed, bearing a cyclic sulphonamide (sultam) and its synthesis is described. For the first time herein we report the synthesis and biological evaluation of the natural product derived cyclic sulfonamides using Grubbs second generation catalyst (Grubbs II) via ring closing metathesis approach. Synthesis of a series of piperlongumine derived sultams is done in a moderate to good yield using Wittig reaction, Ring-Closing Metathesis (RCM) and, amide synthesis by using mixed anhydride, approach. All synthesized compounds were evaluated for anticancer activity and some demonstrated dose dependent reduction in HeLa cell growth. Of these 7, 10 and 14 significantly reduced the cell growth. Consequently their calculated GI50values were found to be 0.1 or 0.1?μM.
- Lad, Nitin P.,Kulkarni, Sarang,Sharma, Rajiv,Mascarenhas, Malcolm,Kulkarni, Mahesh R.,Pandit, Shivaji S.
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p. 870 - 878
(2016/12/18)
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- Synthesis of Substituted Quinolizidines via a Gold-Catalyzed Double Cyclization Cascade
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A novel synthesis of quinolizidines by a cationic gold-catalyzed double cyclization cascade has been developed. The reaction was initiated by the gold-catalyzed 6-exo-dig cyclization of ynamides, which was followed by a second cyclization of an enamide intermediate to provide the corresponding quinolizidine derivatives. The utility of this reaction was demonstrated by application to the synthesis of multi-substituted quinolizidines and by the total synthesis of a quinolizidine alkaloid, (±)-lupinine.
- Nonaka, Shiori,Sugimoto, Kenji,Ueda, Hirofumi,Tokuyama, Hidetoshi
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supporting information
p. 380 - 385
(2016/02/12)
-
- Magnetic polymer nanocomposite-supported Pd: An efficient and reusable catalyst for the Heck and Suzuki reactions in water
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A novel type of magnetically responsive polymer nanocomposite Fe3O4@poly(undecylenic acid-co-4-vinyl pyridine-co-sodium acrylate) (Fe3O4@PUVS) was synthesized by the free radical polymerization of 4-vinyl pyridine (4-VP) with sodium acrylate (SAA) and Fe3O4@undecylenic acid. Pd2+ was then immobilized on this magnetic nanocomposite to form the magnetic Fe3O4@PUVS-Pd catalyst. This catalyst exhibited excellent catalytic activity for the Heck and Suzuki coupling reactions in water, and could be simply separated by using a permanent magnet. The supported catalyst could be used consecutively for six runs without significant loss of catalytic activity.
- Wang, Dongfang,Liu, Wendong,Bian, Fengling,Yu, Wei
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p. 2052 - 2059
(2015/03/18)
-
- Design, synthesis and antibacterial activity of cinnamaldehyde derivatives as inhibitors of the bacterial cell division protein FtsZ
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In an attempt to discover potential antibacterial agents against the increasing bacterial resistance, novel cinnamaldehyde derivatives as FtsZ inhibitors were designed, synthesized and evaluated for their antibacterial activity against nine significant pathogens using broth microdilution method, and their cell division inhibitory activity against four representative strains. In the in vitro antibacterial activity, the newly synthesized compounds generally displayed better efficacy against Staphylococcus aureus ATCC25923 than the others. In particular, compounds 3, 8 and 10 exerted superior or comparable activity to all the reference drugs. In the cell division inhibitory activity, all the compounds showed the same trend as their in vitro antibacterial activity, exhibiting better activity against S. aureus ATCC25923 than the other strains. Additionally, compounds 3, 6, 7 and 8 displayed potent cell division inhibitory activity with an MIC value of below 1 1/4g/mL, over 256-fold better than all the reference drugs.
- Li, Xin,Sheng, Juzheng,Huang, Guihua,Ma, Ruixin,Yin, Fengxin,Song, Di,Zhao, Can,Ma, Shutao
-
-
- Synthesis and biological evaluation of N-(4-phenylthiazol-2-yl)cinnamamide derivatives as novel potential anti-tumor agents
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In this study, a series of novel N-(4-phenylthiazol-2-yl)cinnamamide derivatives (7a-8n) were synthesized and evaluated for their anti-proliferative activities in vitro by MTT assay and a possible antitumor mechanism was also explored. SAR analysis showed that steric effects played an important role on the anti-tumor activity. The most potent analogue 8f showed excellent inhibitions on the K562, Bel7402, A549 and Jurkat cells ranging from sub-micromolar to nanomolar concentration. Compound 8f inhibited Jurkat cells with an IC50 value of 0.035 μM with no apparent toxicity in different non-cancerous cells. Furthermore, it was suggested that the possible mechanism of 8f might be associated with inducing cancer cell apoptosis following flow cytometer analysis and Hoechst 33358 staining assays.
- Luo, Yong,Zhu, Yongxia,Ran, Kai,Liu, Zhihao,Wang, Ningyu,Feng, Qiang,Zeng, Jun,Zhang, Lidan,He, Bing,Ye, Tinghong,Zhu, Shirui,Qiu, Xiaolong,Yu, Luoting
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supporting information
p. 1036 - 1042
(2015/06/25)
-
- Synthesis of Piperlongumine Analogues and Discovery of Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) Activators as Potential Neuroprotective Agents
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The cellular antioxidant system plays key roles in blocking or retarding the pathogenesis of adult neurodegenerative disorders as elevated oxidative stress has been implicated in the pathophysiology of such diseases. Molecules with the ability in enhancing the antioxidant defense thus are promising candidates as neuroprotective agents. We reported herein the synthesis of piperlongumine analogues and evaluation of their cytoprotection against hydrogen peroxide- and 6-hydroxydopamine-induced neuronal cell oxidative damage in the neuron-like PC12 cells. The structure-activity relationship was delineated after the cytotoxicity and protection screening. Two compounds (4 and 5) displayed low cytotoxicity and confer potent protection of PC12 cells from the oxidative injury via upregulation of a panel of cellular antioxidant molecules. Genetically silencing the transcription factor Nrf2, a master regulator of the cellular stress responses, suppresses the cytoprotection, indicating the critical involvement of Nrf2 for the cellular action of compounds 4 and 5 in PC12 cells.
- Peng, Shoujiao,Zhang, Baoxin,Meng, Xianke,Yao, Juan,Fang, Jianguo
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p. 5242 - 5255
(2015/08/03)
-
- Synthesis and antibacterial activity of 4'3-O-(trans-β-arylacrylamido)carbamoyl azithromycin analogs
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Novel 4'3-O-(trans-β-arylacrylamido)carbamoyl azithromycin analogs were designed, synthesized and evaluated for their antibacterial activity against nine significant pathogens using broth microdilution method. A majority of these derivatives maintained the activity of azithromycin against susceptible Streptococcus pyogenes and all the compounds demonstrated remarkably improved activity compared with the references against all the three phenotypes of resistant Streptococcus pneumoniae. In particular, compound 24 exhibited the most potent activity against susceptible Staphylococcus aureus (MIC = 0.5 μg/mL), S. pneumoniae (MIC = 0.06 μg/mL) and S. pyogenes (MIC = 0.25 μg/mL). The most active compound 7 (MIC = 0.015 μg/mL) against resistant S. pneumoniae expressing the mefA gene, exhibited 512 and 256-fold more potent activity than erythromycin and azithromycin, respectively. Compounds 28 (MIC = 0.5 μg/mL), 29 (MIC = 0.25 μg/mL) and 30 (MIC = 0.5 μg/mL) demonstrated potent activity against resistant S. pneumoniae expressing the ermB gene, which were 256, 512 and 256-fold better than the references, respectively.
- Yan, Mi,Ma, Xiaodong,Dong, Ruiqian,Li, Xin,Zhao, Can,Guo, Zhenzhen,Shen, Yan,Liu, Fang,Ma, Ruixin,Ma, Shutao
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p. 506 - 515
(2015/10/06)
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- A highly efficient transformation of cis- to trans-cinnamic acid derivatives by iodine
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Cinnamic acid derivatives (CAs), which have proven to be versatile components, are present in abundance in biologically active natural products, and are widely used as intermediates in the manufacture of pharmaceuticals, and chemicals. The presence of cis- and trans-CAs created difficulties for natural product and organic synthetic studies. A highly efficient method that utilized iodine to entirely convert cis- CAs into their trans-forms was developed to solve this problem. The mechanism of study revealed this conversion occurred via an anti-diiodo intermediate.
- Li, Zhen-Jie,Cai, Le,Mei, Rui-Feng,Dong, Jian-Wei,Li, Shu-Quan,Yang, Xue-Qiong,Zhou, Hao,Yin, Tian-Peng,Ding, Zhong-Tao
-
supporting information
p. 7197 - 7200
(2015/12/12)
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- Carboxymethylcellulose-supported palladium nanoparticles generated in situ from palladium(II) carboxymethylcellulose as an efficient and reusable catalyst for ligand- and base-free Heck-Matsuda and Suzuki-Miyaura couplings
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A novel palladium(II) carboxymethylcellulose (CMC-PdII) was prepared from sodium carboxymethylcellulose (CMC-Na) and PdCl2 in aqueous solution. It was employed as precatalyst for Heck-Matsuda and Suzuki-Miyaura couplings. The true catalytic species are active soluble Pd(0) or Pd(0) clusters released from palladium nanoparticles deposited on the CMC molecular skeleton (CMC-Pd0) formed in situ from CMC-PdII in the catalytic process.
- Xiao, Jinlong,Lu, Zhangxiu,Li, Zhipeng,Li, Yiqun
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p. 646 - 652
(2015/09/01)
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- Influence of pendent alkyl chains on Heck and Sonogashira C-C coupling catalyzed with palladium(II) complexes of selenated Schiff bases having liquid crystalline properties
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The effect of pendent alkyl chain lengths on Heck and Sonogashira coupling has been investigated for the first time using air and moisture insensitive complexes, [PdLCl] (1-4), of selenated Schiff bases (L = L1-L4), differing in length and number of pendent alkyl chain(s) and behaving as a (Se, N, O -) type of ligand. Differential scanning calorimetric (DSC) and polarized optical microscopic (POM) investigations show liquid crystalline nature of L1 and L2, which have one pendent alkyl chain of size C18 and C10 respectively. The yields of coupled products in catalytic Heck and Sonogashira coupling reactions were found good when amount of 1-4 used for them was 1.0 and 0.5 mol% respectively. The catalytic efficiency decreases with alkyl chain length of pendent arm of ligand for Heck coupling but remains unaffected in case of Sonogashira coupling. The in situ generation of palladium nanoparticles (NPs) protected with organoselenium species occurs in the case of Heck coupling. The length of pendent alkyl chain appears to control the dispersion and composition of these NPs and consequently the catalytic efficiency for Heck coupling. The black residues formed in the case of Sonogashira coupling catalyzed with 1 and 4 were found to have small fraction of NPs and a large proportion of big size aggregates. Their compositions for both the catalysts have been found nearly the same and due to predominance of aggregates, the efficiency remains almost unchanged on varying length of pendent alkyl chain. The two phase test for Heck coupling indicates that catalysis is largely heterogeneous.
- Rao, Gyandshwar Kumar,Kumar, Arun,Singh, Mahabir Pratap,Kumar, Ajay,Biradar, Ashok Manikrao,Singh, Ajai K.
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-
- Phenylalanine ammonia lyase catalyzed synthesis of amino acids by an MIO-cofactor independent pathway
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Phenylalanine ammonia lyases (PALs) belong to a family of 4-methylideneimidazole-5-one (MIO) cofactor dependent enzymes which are responsible for the conversion of L-phenylalanine into trans-cinnamic acid in eukaryotic and prokaryotic organisms. Under conditions of high ammonia concentration, this deamination reaction is reversible and hence there is considerable interest in the development of PALs as biocatalysts for the enantioselective synthesis of non-natural amino acids. Herein the discovery of a previously unobserved competing MIO-independent reaction pathway, which proceeds in a non-stereoselective manner and results in the generation of both L- and D-phenylalanine derivatives, is described. The mechanism of the MIO-independent pathway is explored through isotopic-labeling studies and mutagenesis of key active-site residues. The results obtained are consistent with amino acid deamination occurring by a stepwise E1cB elimination mechanism. All manner of things: A competing MIO-independent (MIO=4-methylideneimidazole-5-one) reaction pathway has been identified for phenylalanine ammonia lyases (PALs), which proceeds in a non-stereoselective manner, resulting in the generation of D-phenylalanine derivatives. The mechanism of D-amino acid formation is explored through isotopic-labeling studies and mutagenesis of key active-site residues.
- Lovelock, Sarah L.,Lloyd, Richard C.,Turner, Nicholas J.
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p. 4652 - 4656
(2014/05/20)
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- Palladium supported on a magnetic microgel: An efficient and recyclable catalyst for Suzuki and Heck reactions in water
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A novel heterogeneous Pd catalyst was synthesized by anchoring palladium(ii) onto poly(undecylenic acid-co-N-isopropylacrylamide-co-potassium 4-acryloxyoylpyridine-2,6-dicarboxylate)-coated Fe3O4 (Fe3O4@PUNP) magnetic microgel. The catalyst (Fe 3O4@PUNP-Pd) was characterized by FT-IR, TEM, VSM, XRD and XPS, and the loading level of Pd in Fe3O4@PUNP-Pd catalyst was measured to be 0.330 mmol g-1 by AAS. This catalyst exhibits excellent catalytic activity for the Suzuki and Heck reactions in water. In addition, the Fe3O4@PUNP-Pd catalyst can be easily separated and recovered with an external permanent magnet, and the reuse experiment shows that it can be used consecutively six times without significant loss in catalytic activity.
- Yang, Jianhua,Wang, Dongfang,Liu, Wendong,Zhang, Xi,Bian, Fengling,Yu, Wei
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p. 3429 - 3437
(2013/12/04)
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- Enzymatic synthesis of phenol polymer and its functionalization
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In phosphate buffer (pH = 7.0) containing sodium dodecyl sulfate (SDS), an environmentally friendly system, enzymatic polymerization of phenol catalyzed by horseradish peroxidase (HRP) was efficiently performed. The obtained phenol polymer is partly soluble in common solvents, such as acetone, THF and DMF. IR analysis shows that the polymer is composed of phenylene and oxyphenylene units. The functionalization of the phenol polymer was performed by reacting with epoxy chloropropane and triethylene-tetramine following, and then insoluble aminated phenol polymer was obtained. The aminated phenol polymer was adopted as carrier to prepare a novel supported palladium catalyst (PP-N-Pd) for Heck reaction. PP-N-Pd shows high catalytic performance for Heck reactions of aryl iodides with acrylic acid or styrene and the yields of trans-products were higher than 90%. Under the optimized conditions, aryl bromides and activated aryl chloride also reacted with alkenes to give the yields of above 80%. XPS analysis indicates that the main coordination atom in PP-N-Pd is N and the chemical valence of palladium in PP-N-Pd is Pd2+. The novel supported catalyst also shows good recyclability for Heck reaction.
- Zhang, Lei,Zhao, Wenshan,Chen, Hengzhen,Cui, Yuanchen
-
-
- Synthesis and antitumor activity of 1,3,4-oxadiazole possessing 1,4-benzodioxan moiety as a novel class of potent methionine aminopeptidase type II inhibitors
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A series of 1,3,4-oxadiazole derivatives containing 1,4-benzodioxan moiety (7a-7q) have been designed, synthesized and evaluated for their antitumor activity. Most of the synthesized compounds were proved to have potent antitumor activity and low toxicity. Among them, compound 7a showed the most potent biological activity against Human Umbilical Vein Endothelial cells, which was comparable to the positive control. The results of apoptosis and flow cytometry (FCM) demonstrated that compound 7a induce cell apoptosis by the inhibition of MetAP2 pathway. Molecular docking was performed to position compound 7a into MetAP2 binding site in order to explore the potential target.
- Sun, Juan,Li, Ming-Hui,Qian, Shao-Song,Guo, Feng-Jiao,Dang, Xiao-Fang,Wang, Xiao-Ming,Xue, Ya-Rong,Zhu, Hai-Liang
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supporting information
p. 2876 - 2879
(2013/06/26)
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- Sodium tetraborate/benzyltriethylammonium chloride-mediated synthesis of substituted cinnamic acids from aromatic aldehydes and aliphatic carboxylic acids
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A simple, efficient, and cost-effective method has been developed for the synthesis of some cinnamic acid derivatives in moderate to high yields (63-86%) by a one-pot condensation reaction of benzaldehyde and aliphatic carboxylic acids in the presence of sodium tetraborate and benzyltriethylammonium chloride, and N-methyl-pyrrolidinone as solvent. The reaction requires high temperatures (reflux at 180-190°C) and strong basic conditions, which have been generated by pyridine and 4-dimethylaminopyridine added to the reaction medium.
- Nechifor, Marioara,Chiriac, Constantin I.,Tanasa, Fulga
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p. 161 - 164
(2014/04/03)
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- Immobilized palladium on surface-modified Fe3O 4/SiO2 nanoparticles: As a magnetically separable and stable recyclable high-performance catalyst for Suzuki and Heck cross-coupling reactions
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A palladium-based catalyst (Fe3O4/SiO 2/HPG-OPPh2-PNP) supported on chlorodiphenylphosphine- functionalized magnetic nanoparticles was successfully prepared from Fe 3O4/SiO2 with sequential attachment of glycerol and chlorodiphenylphosphine, followed by treatment of an ethanolic solution of palladium chloride with hydrazine. The as-prepared catalyst was characterized by ICP-AES, FTIR, XRD, SEM, and TEM. The Fe3O4/SiO 2/HPG-OPPh2-PNP was found as a magnetically separable and highly active catalyst for Suzuki coupling reactions of aryl iodides, bromides, and chlorides as well as Heck reactions of aryl iodides and bromides. Under appropriate conditions, all reactions afforded the desired products in moderate to excellent yields. Moreover, this catalyst can be easily recovered by using a magnetic field and directly reused for at least six cycles without significant loss of its activity.
- Du, Qingwei,Zhang, Wei,Ma, Hao,Zheng, Jia,Zhou, Bo,Li, Yiqun
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experimental part
p. 3577 - 3584
(2012/06/29)
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- Water mediated Heck and Ullmann couplings by supported palladium nanoparticles: Importance of surface polarity of the carbon spheres
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Heterogeneous palladium nanoparticle catalysts that are supported on amphiphilic carbon spheres (Pd@CSP) have been utilized for water-mediated Heck coupling reactions of aryl halides with different alkenes under phosphine free as well as aerobic conditions. Furthermore, a variety of Heck coupling reactions using different bases and solvents, including organic polar and non-polar solvents, have been explored. Aryl bromides are also well activated in Heck coupling reactions in organic polar solvent and as well as in water. In addition, Ullmann coupling reactions of aryl iodides have been catalyzed in water with the aid of phase transfer catalysts (PTC) in moderate yields. A plausible mechanism for the catalytic activity of Pd@CSP in the case of the Ullmann reaction is also established. It has been demonstrated that the hydrophobic effects of the catalyst surface play an important role in catalyst activity in water. In addition, the E-factor analysis verified that our present protocol is significantly comparable with other catalytic systems and explains the improved greenness. Moreover, the catalyst described in this process is not only greener, but also retains its significant activity for up to four catalytic cycles for the Heck coupling reactions. The surface polarity of the amphiphilic carbon spheres results in higher activity under these conditions.
- Kamal, Ahmed,Srinivasulu, Vunnam,Seshadri,Markandeya, Nagula,Alarifi,Shankaraiah, Nagula
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p. 2513 - 2522
(2013/02/21)
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- An efficient and recyclable ligand-free PEG1000-DIL/toluene temperature-dependent biphasic system for palladium catalysed Heck reactions
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The Heck reaction of aryl halides with terminal olefins was successfully performed by using Pd (OAc)2 as the catalyst in a ligand-free PEG1000-DIL (PEG1000-based dicationic ionic liquid)/toluene system exhibiting temperature-dependent biphasic behavior. In addition, the isolation of the products is readily performed by a simply decantation, and the catalytic system can be recycled and reused without loss of catalytic activity.
- Liu, Xiang,Yao, Kai,Hu, Yu-Lin,Lu, Ming
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experimental part
p. 731 - 733
(2012/03/10)
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- Triazine functionalized ordered mesoporous polymer: A novel solid support for Pd-mediated C-C cross-coupling reactions in water
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A new functionalized mesoporous polymer (MPTAT-1) has been synthesized via organic-organic radical polymerization of 2,4,6-triallyloxy-1,3,5-triazine (TAT) in aqueous medium in the presence of an anionic surfactant (sodium dodecyl sulfate) as template. Powder XRD and TEM image analysis suggests the presence of ordered 2D-hexagonal arrangement of pores in the material. N2 sorption analysis reveals a moderately good surface area 135 m2 g-1 for this mesoporous polymer. The template free MPTAT-1 acts as an excellent support for immobilizing Pd(ii) at its surface and the resulting material showed very good catalytic activity in several C-C cross-coupling reactions like Mizoroki-Heck, Sonogashira and Suzuki-Miyaura in an environmentally benign reaction medium, water. The catalyst exhibits very high catalytic activity for the coupling of various aryl halides including aryl chlorides with alkenes or alkynes and the sodium salt of (trihydroxy) phenylborate. Due to strong binding with the functional groups of the polymer, the anchored Pd(ii) could not leach out from the surface of the mesoporous catalyst during the reaction and it has been reused several times without appreciable loss in catalytic activity.
- Modak, Arindam,Mondal, John,Sasidharan, Manickam,Bhaumik, Asim
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experimental part
p. 1317 - 1331
(2011/06/23)
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- One-pot efficient Heck coupling in water catalyzed by palladium nanoparticles tethered into mesoporous organic polymer
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A new palladium grafted mesoporous organic polymer catalyst has been synthesized through the reaction of palladium(II) acetate with mesoporous poly-triallylamine (MPTA-1) in methanol. Powder XRD, HR TEM, FE SEM-EDS, AAS, UV-vis spectroscopic tools are employed to characterize this supported palladium catalyst Pd-MPTA-1. The Heck coupling reactions between a series of aryl halides and alkenes have afforded the corresponding C-C coupling products in good yield over this Pd-catalyst using water as reaction medium. This protocol provides a simple strategy for the generation of a variety of new C-C bonds by using this recyclable heterogeneous catalyst under environmentally benign conditions.
- Mondal, John,Modak, Arindam,Bhaumik, Asim
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experimental part
p. 40 - 48
(2012/01/13)
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- Synthesis of chondramide a analogues with modified β-tyrosine and their biological evaluation
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Starting from cinnamates 9, obtained by Wittig reaction or Heck coupling, the diols 17 were prepared by asymmetric dihydroxylation. This was followed by a regioselective substitution of the 3-OH group with hydrazoic acid under Mitsunobu conditions. Methylation of the 2-OH group and reduction of the azide group led to the β-tyrosine derivatives 8. Condensation with the dipeptide acid 6 furnished the tripeptide part of the chondramides. The derived acids 21 were combined with the hydroxy ester 7 to the esters 22. Cleavage of the tert-butyl groups and intramolecular lactam formation gave rise to the chondramide A analogues 2 b-k. Growth inhibition assays showed most of the analogues to be biologically active. Some of them even reach the activity of jasplakinolide. It can be concluded that the 4-position of the aryl ring in the β-tyrosine of chondramide A tolerates structural modifications quite well.
- Zhdanko, Alexander,Schmauder, Anke,Ma, Christopher I.,Sibley, L. David,Sept, David,Sasse, Florenz,Maier, Martin E.
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supporting information; experimental part
p. 13349 - 13357
(2012/02/14)
-
- Alum [KA1(S04)2. 12H20]: An efficient, novel, clean, catalyst for Doebner Knoevenagel reaction for the efficient production of αβ-unsaturated acids
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Alum mediated solvent free, microwave enhanced, clean process for the production of -unsaturated acids 3, 5 and 7 is described. Only 10 mole % of alum is enough in this protocol to achieve optimal yields and this protocol is fairly general and applicable to heterocyclic aldehydes and benzopyran 3-aldehydes.
- Suresh, Dhruva Kumar,Sandhu, Jagir S.
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experimental part
p. 1479 - 1483
(2011/12/02)
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- First bovine serum albumin-promoted synthesis of enones, cinnamic acids and coumarins in ionic liquid: An insight into the role of protein impurities in porcine pancreas lipase for olefinic bond formation
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During studies on exploiting the catalytic promiscuity of crude porcine pancreas lipase (PPL) in ionic liquid for C=C bond formations, bovine serum albumin (BSA) was found to be competing for these reactions. After a detailed investigation, we establish that these transformations are possible by unspecific protein catalysis rather than catalytic promiscuity of "PPL" - a first insight into the role of protein impurities in crude enzyme. Thus, a novel and highly efficient, environmentally friendly approach involving synergistic catalysis by bovine serum albumin-1-butyl-3- methylimidazolium bromide (BSA-[bmim]Br) has been developed for the synthesis of (E)-α,β-unsaturated compounds including a one-pot cascade synthesis of cinnamic acids and coumarins via aldol, Knoevenagel and Knoevenagel-Doebner condensations.
- Sharma, Nandini,Sharma, Upendra K.,Kumar, Rajesh,Katoch, Nidhi,Kumar, Rakesh,Sinha, Arun K.
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scheme or table
p. 871 - 878
(2011/06/19)
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- Synthesis, biological evaluation, and molecular modeling of cinnamic acyl sulfonamide derivatives as novel antitubulin agents
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A series of novel cinnamic acyl sulfonamide derivatives (9a-16e) have been designed and synthesized and their biological activities were also evaluated as potential tubulin polymerization inhibitors. Among all the compounds, 10c showed the most potent growth inhibitory activity against B16-F10 cancer cell line in vitro, with an IC50 value of 0.8 μg/mL. Docking simulation was performed to insert compound 10c into the crystal structure of tubulin at colchicine binding site to determine the probable binding model. Based on the preliminary results, compound 10c with potent inhibitory activity in tumor growth may be a potential anticancer agent.
- Luo, Yin,Qiu, Ke-Ming,Lu, Xiang,Liu, Kai,Fu, Jie,Zhu, Hai-Liang
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experimental part
p. 4730 - 4738
(2011/09/20)
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- The combination of 4-anilinoquinazoline and cinnamic acid: A novel mode of binding to the epidermal growth factor receptor tyrosine kinase
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A novel type of cinnamic acid quinazoline amide derivatives (20-42), which designed the combination between quinazoline as the backbone and various substituted cinnamic acid as the side chain, have been synthesized and their biological activities were evaluated within cytotoxicity assay firstly and then potent EGFR inhibitory activity. Compound 42 demonstrated the most potent inhibitory activity (IC50 = 0.94 μM for EGFR), which could be optimized as a potential EGFR inhibitor in the further study. Docking simulation was performed to position compound 42 into the EGFR active site to determine the probable binding model. Analysis of the binding conformation of 42 in active site displayed compound 42 was stabilized by hydrogen bonding interactions with Lys822, which was different from other derivatives. In the further study, Compounds 43 and 44 had been synthesized and their biological activities were also evaluated, which were the same as that we expected. Compound 43 has demonstrated significant EGFR (IC50 = 0.12 μM) and tumor growth inhibitory activity as a potential anticancer agent.
- Li, Dong-Dong,Lv, Peng-Cheng,Zhang, Hui,Zhang, Hong-Jia,Hou, Ya-Ping,Liu, Kai,Ye, Yong-Hao,Zhu, Hai-Liang
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experimental part
p. 5012 - 5022
(2011/10/04)
-
- Regioselective addition of thiophenol to α,β-unsaturated N-acylbenzotriazoles
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Regioselective addition of thiophenol to α,β-unsaturated N-acylbenzotriazoles has been achieved by controlling the conditions. Thus, three types of products, namely α,β-unsaturated thioesters, β-thiophenoxy substituted N-acylbenzotriazoles, and β-thiophenoxy substituted thioesters were selectively obtained in good to excellent yields.
- Xia, Ziming,Lv, Xin,Wang, Wencun,Wang, Xiaoxia
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supporting information; experimental part
p. 4906 - 4910
(2011/10/07)
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- Supported nanosized palladium on superparamagnetic composite microspheres as an efficient catalyst for Heck reaction
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A magnetically separable palladium catalyst has been easily synthesized by immobilizing palladium nanoparticles on the surface of superparamagnetic composite microspheres. It can promote Heck cross-coupling reactions efficiently without an inert atmosphere. The novel catalyst can be conveniently recovered by applying a permanent magnet externally and reused at least six times without significant loss of its catalytic activity.
- Yuan, Dingzhong,Zhang, Qiuyu,Dou, Jinbo
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experimental part
p. 606 - 610
(2010/12/18)
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- Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres supported palladium complex as an efficient catalyst for Heck reaction
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Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst. The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere. In addition, the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.
- Yuan, Ding Zhong,Zhang, Qiu Yu,Dou, Jin Bo
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scheme or table
p. 1062 - 1066
(2011/10/08)
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