- Promising Non-cytotoxic Monosubstituted Chalcones to Target Monoamine Oxidase-B
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A library of monosubstituted chalcones (1-17) bearing electron-donating and electron-withdrawing groups on both aromatic rings were selected. The cell viability on human tumor cell lines was evaluated first. The compounds unable to induce detectable cytotoxicity (1, 13, and 14) were tested using the monoamine oxidase (MAO) activity assay. Interestingly, they inhibit MAO-B, acting as competitive inhibitors, with 13 and 14 showing the best profiles. In particular, 13 exhibited a potency higher than that of safinamide, taken as a reference. Docking studies and crystallographic analysis showed that in human MAO-B 13 binds with the halogen-substituted aromatic ring in the entrance cavity, similar to safinamide, whereas 14 is accommodated in the opposite way. The main conclusion of this cell biology, biochemistry, and structural study is to highlights 13 as a chalcone derivative that is worth consideration for the development of novel MAO-B-selective inhibitors for the treatment of neurodegenerative diseases.
- Iacovino, Luca G.,Pinzi, Luca,Facchetti, Giorgio,Bortolini, Beatrice,Christodoulou, Michael S.,Binda, Claudia,Rastelli, Giulio,Rimoldi, Isabella,Passarella, Daniele,Di Paolo, Maria Luisa,Dalla Via, Lisa
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supporting information
p. 1151 - 1158
(2021/06/30)
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- Double-edged Swords: Diaryl pyrazoline thiazolidinediones synchronously targeting cancer epigenetics and angiogenesis
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In the present study, two novel series of compounds incorporating naphthyl and pyridyl linker were synthesized and biological assays revealed 5-((6-(2-(5-(2-chlorophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl)-2-oxoethoxy) naphthalene-2-yl)methylene)thiazolidine-2,4-dione (14b) as the most potent dual inhibitors of vascular endothelial growth factors receptor-2 (VEGFR-2) and histone deacetylase 4 (HDAC4). Compounds 13b, 14b, 17f, and 21f were found to stabilize HDAC4; where, pyridyl linker swords were endowed with higher stabilization effects than naphthyl linker. Also, 13b and 14b showed best inhibitory activity on VEGFR-2 as compared to others. Compound 14b was most potent as evident by in-vitro and in-vivo biological assessments. It displayed anti-angiogenic potential by inhibiting endothelial cell proliferation, migration, tube formation and also suppressed new capillary formation in the growing chick chorioallantoic membranes (CAMs). It showed selectivity and potency towards HDAC4 as compared to other HDAC isoforms. Compound 14b (25 mg/kg, i.p.) also indicated exceptional antitumor efficacy on in-vivo animal xenograft model of human colorectal adenocarcinoma (HT-29). The mechanism of action of 14b was also confirmed by western blot.
- Kumar, Alan P.,Meyer-Almes, Franz-Josef,Ramaa, C. S.,Safuan, Sabreena,Schweipert, Markus,Tilekar, Kalpana,Upadhyay, Neha
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- Synthesis, characterization and α-amylase and α-glucosidase inhibition studies of novel vanadyl chalcone complexes
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A series of chalcone ligands and their corresponding vanadyl complexes of composition [VO (LI–IV)2(H2O)2]SO4 (where LI = 1,3-Diphenylprop-2-en-1-one, LII = 3-(2-Hydroxy-phenyl)-1-phenyl-propenone, LIII = 3-(3-Nitro-phenyl)-1-phenyl-propenone, LIV = 3-(4-Methoxy-phenyl)-1-phenyl-propenone) have been synthesized and characterized using various spectroscopic (Fourier-transform infrared, electrospray ionization mass, nuclear magnetic resonance, electron paramagnetic resonance, thermogravimetric analysis, vibrating sample magnetometer) and physico-analytic techniques. Antidiabetic activities of synthesized complexes along with chalcones were evaluated by performing in vitro and in silico α-amylase and α-glucosidase inhibition studies. The obtained results displayed moderate to significant inhibition activity against both the enzymes by vanadyl chalcone complexes. The most potent complexes were further investigated for the enzyme kinetic studies and displayed the mixed inhibition for both the enzymes. Further, antioxidant activity of vanadyl chalcone complexes was evaluated for their efficiency to release oxidative stress using 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay, and two complexes (Complexes 2 and 4) have demonstrated remarkable antioxidant activity. All the complexes were found to possess promising antidiabetic and antioxidant potential.
- Kaur, Mandeep,Kaushal, Raj
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- Facile microwave-assisted synthesis and antitubercular evaluation of novel aziridine derivatives
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Novel 2-(aryloxymethyl)aziridines and 2-((3-aryl-1-phenylallyloxy)methyl)aziridine derivatives were prepared via ring-opening reaction of epoxides. The synthesized derivatives were characterized by using elemental analysis (EA), FT-IR, 13C NMR, and 1H NMR. The in vitro antitubercular activities of the synthesized compounds were evaluated against Mycobacterium tuberculosis H37Rv (MTB H37Rv) strain using MTT-MABA assay. All the aziridine derivatives exhibited improved persuasive antitubercular activity against MTB H37Rv in comparison with standard drugs. Among the tested compounds, 2-(naphthalene-1-yloxy) methyl aziridine (5b), 2-(naphthalene-2-yloxy)methylaziridine (5c), 2-(m-tolyloxymethyl)aziridine (5e), 2-(3-(4-methoxyphenyl)-1-phenylalloxy)methylaziridine (12b) and 2-(3-(2-chlorophenyl)-1-phenylallyloxy)methylaziridine (12c) revealed promising activity against MTB H37Rv. Specifically, compound 5b and 12 b showed three-times more active (MIC = 0.5 μg/mL) than the standard drugs ethambutol (MIC = 1.56 μg/mL) and ciprofloxacin (MIC = 1.56 μg/mL).
- Sarojini, Perumal,Jeyachandran, Malaichamy,Sriram, Dharmarajan,Ranganathan, Palraj,Gandhimathi
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- Design, synthesis and evaluation of 2,4,6-substituted pyrimidine derivatives as BACE-1 inhibitor: Plausible lead for alzheimer’s disease
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Alzheimer’s disease is one of the most common neurodegenerative disorder afflicting a large mass of population. BACE-1 (β-secretase) is an aspartyl protease of the amyloidogenic pathway considered responsible for Alzheimer’s disease (AD). Since it catalyzes the rate-limiting step of Aβ-42 production from amyloid precursor protein (APP), its inhibition is considered a viable thera-peutic strategy. We have reported the design of small molecular weight compounds supposed to be blood brain permeable as BACE-1 inhibitors. The clue for the design of this series is drawn from the previously designed series from our research group. Objective: Design and synthesis of 2,4,6-substituted pyrimidine derivatives has been reported. In vitro FRET-based screening of synthesized derivatives was performed to evaluate the BACE-1 inhibition profile. Methods: Based on the docking simulation studies, a library of derivatives was designed, synthesized and evaluated for BACE-1 inhibition in-vitro. The docking studies were performed on Glide (Schrodinger suite) and Molegro virtual docker. Theoretical toxicity was predicted using Osiris Property Explorer. The synthesized compounds were tested for BACE-1 inhibition using in vitro assay based on Fluorescence Resonance Energy Transfer technique. The percent inhibition was cal-culated as a measure of activity. Results: The designed compounds revealed strong interactions with the desired amino acids of BACE-1 active sites. The aromatic rings placed at the fourth and sixth position of the pyrimidine ring occupied S1 and S3 substrate-binding clefts while the amino group formed hydrogen bonding interactions with Asp32 and Asp228. In silico data ensured that the compounds were orally bioavailable and brain permeable. The in vitro testing showed that the compounds inhibited BACE-1 at 10μM concentration. Conclusion: Compounds substituted with m-benzyloxy on one aromatic ring and o,p-di-chloro on another aromatic ring displayed maximum BACE-1 inhibition. Compound 2.13A displayed high docking score and was found to be most potent with IC50 of 6.92μM. The series displayed a good correlation between the docking score and BACE-1 inhibition profile.
- Jadhav, Hemant R.,Jain, Priti,Wadhwa, Pankaj K.
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p. 1194 - 1206
(2021/12/21)
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- Antiproliferative effects of chalcones on T cell acute lymphoblastic leukemia-derived cells: Role of PKCβ
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In this study, a series of 20 chalcone derivatives was synthesized, and their antiproliferative activity was tested against the human T cell acute lymphoblastic leukemia-derived cell line, CCRF-CEM. On the basis of the structural features of the most active compounds, a new library of chalcone derivatives, according to the structure–activity relationship design, was synthesized, and their antiproliferative activity was tested against the same cancer cell line. Furthermore, four of these derivatives (compounds 3, 4, 8, 28), based on lower IC50 values (between 6.1 and 8.9 μM), were selected for further investigation regarding the modulation of the protein expression of RACK1 (receptor for activated C kinase), protein kinase C (PKC)α and PKCβ, and their action on the cell cycle level. The cell cycle analysis indicated a block in the G0/G1 phase for all four compounds, with a statistically significant decrease in the percentage of cells in the S phase, with no indication of apoptosis (sub-G0/G1 phase). Compounds 4 and 8 showed a statistically significant reduction in the expression of PKCα and an increase in PKCβ, which together with the demonstration of an antiproliferative role of PKCβ, as assessed by treating cells with a selective PKCβ activator, indicated that the observed antiproliferative effect is likely to be mediated through PKCβ induction.
- Corsini, Emanuela,Facchetti, Giorgio,Esposito, Sara,Maddalon, Ambra,Rimoldi, Isabella,Christodoulou, Michael S.
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- Novel chalcones derivatives with potential antineoplastic activity investigated by docking and molecular dynamics simulations
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Glioblastoma is an aggressive primary tumor of the central nervous system (CNS). Is the most aggressive among infiltrative gliomas arising from the CNS. This tumor has low patient survival rate and several studies aiming at developing new drugs have increased. Patients with this cancer type face significant morbidity and mortality. This study evaluated the antineoplastic activity of synthetic chalcones (3a-3f) using in vitro glioblastoma models and molecular modeling. Cytotoxicity assay showed that Astrocitoma Hospital Ofir Loyola No 1 (AHOL1) and Uppsala 87 neoplastic glioblastoma lines (U87) cellular viability were significantly reduced compared to Healthy human fibroblasts cell lines (AN27) when exposed to chalcones. Interaction with the serine amino acid was present in the most promising and the reference binder docking, suggesting its importance inhibiting cell growth. Comparative analysis between the reference ligands and the molecules showed that the amino acid LYS352 present in all fittings, suggesting that this is the main amino acid for interaction with tubulin and are consistent with those in cytotoxicity assay, suggesting antineoplastic potential in glioblastoma. Long trajectory molecular dynamics studies were also carried out in order to investigate stability and conformations amongst the chalcones bound tubulin as well, in comparison to doxorubicin (here used as control), however future studies are needed to further assess the mechanism of inhibition of chalcones used in this investigation. Communicated by Ramaswamy H. Sarma.
- Neto, Raimundo de A. M.,Santos, Cleydson B. R.,Henriques, Shayanne V. C.,Machado, Letícia de O.,Cruz, Jorddy N.,da Silva, Carlos H. T. de P.,Federico, Leonardo B.,Oliveira, Edivaldo H. C. de,de Souza, Michel P. C.,da Silva, Patrícia N. B.,Taft, Carlton A.,Ferreira, Irlon M.,Gomes, Madson R. F.
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- Potassium Natural Asphalt Sulfonate (K-NAS): Synthesis and characterization as a new recyclable solid basic nanocatalyst and its application in the formation of carbon–carbon bonds
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In this research, we synthesized and characterized a new heterogeneous basic nanocatalyst and its catalytic application was studied in the Claisen-Schmidt and Knoevenagel condensations. In order to prepare this nanocatalyst, first, the Iranian natural asphalt was sulfonated with the concentrated sulfuric acid and then, converted to the potassium natural asphalt sulfonate (K-NAS). In order to characterization of the nanocatalyst, used of FT-IR spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and thermogravimetric analysis (TGA) techniques. This new basic heterogeneous nanocatalyst have advantages such as being eco-friendly, huge specific surface area, high reactivity and recyclability.
- Falah, Saeid,Soleiman-Beigi, Mohammad,Kohzadi, Homa
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- The Use of Modified Clay as an Efficient Heterogeneous and Ecofriendly Catalyst for the Synthesis of Chalcones via Claisen-Schmidt Condensation
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Abstract: Clay modified by potassium fluoride (KF-modified clay) was used as an ecological alternative and heterogeneous catalyst for the preparation of chalcones via Claisen-Schmidt condensation. In this paper, we have synthesized classical chalcones by condensation of benzaldehyde substituents with acetophenone. Moreover, the other chalcones were also synthesized during the condensation of benzaldehyde substituents with 2-acetylfuran. All the results obtained show that our material can be used as an effective catalyst for the synthesis of chalcones with good yield included between 90 and 99%. The catalyst recycle study shows that the modified clay can be reused four times without a decrease in catalytic activity.
- Bentahar, S.,Dbik, A.,Khomri, M. El,Lacherai, A.,Messaoudi, N. El,Sabour, A.,Taleb, M. Ait
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p. 983 - 990
(2020/08/24)
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- Some thiocarbamoyl based novel anticathepsin agents
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Cathepsins have emerged as important targets in various tissues degenerative disorders due to their involvement in degradation of extracellular matrices and endogenous protein turnover. Elevated cathepsins levels vis-à-vis decreased concentration of endogenous inhibitors has been reported at different diseased sites. The design and synthesis of specific potential anti-cathepsin agents is therefore of great significance. Most of potential anti-cathepsin agents developed have peptide based structures with an active warhead. Due to oral instability and immunogenic problems related to peptidyl inhibitors drift the synthesis and evaluation of non-peptide cathepsin inhibitors in last two decades. The present work provides a detailed structure activity relationship for developing potential non-peptide anticathepsin agents based on in-vitro inhibition studies of a library of synthesized thiocarbamoyl- non-peptide inhibitors.
- Kaur, Ravinder,Raghav, Neera
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- Studies of NMR Chemical Shifts of Chalcone Derivatives of Five-membered Monoheterocycles and Determination of Aromaticity Indices
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A series of the chalcone derivatives of the five-membered monoheterocyclic compounds, (E)-1-aryl-3-heteroarylpropen-1-ones, were prepared by aldol condensation of the corresponding aldehydes of thiophene, pyrrole, and furan with m- and p-substituted acetophenones. Similar condensation of the acetyl compounds of the heterocycles with m- and p-substituted benzaldehydes gave another series of the chalcone derivatives, (E)-1-heteroaryl-3-arylpropen-1-ones. The 13C chemical shift values (δC) of the chalcone derivatives were determined in order to find if they correlated with the Hammett σ values. A good correlation, especially for the β-C for both series, was found for the 13C chemical shift values (δC) of the chalcone derivatives with the Hammett σ values. The chemical shift values of the β-C of the heterocyclic compounds were plotted against those of the benzene derivatives. The resulting slopes were found to be close to the values of the aromaticity indices.
- Jeong, Eun Jeong,Lee, In-Sook Han
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p. 668 - 673
(2019/07/12)
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- Development of 5-(Aryl)-3-phenyl-1H-pyrazole Derivatives as Potent Antimicrobial Compounds
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A series of 16 chalcone compounds were synthesized by Claisen-Schmidt condensation of various aldehydes with acetophenone using KOH as a base in ethanol. The reaction affords the desired products in good yields. Then all the 16 compounds were converted into pyrazoles by treating with hydrazine hydrate in ethanol under reflux condition. Both chalcones and pyrazoles were screened for their in vitro antibacterial (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) and antifungal (Aspergillus flavus, Chrysosporium keratinophilum and Candida albicans) activity. Biological activities of these compounds were compared with those of commercially available antibiotic ampicillin and antifungal agent miconazole. Pyrazoles were found to be most active and effective than corresponding chalcones for antimicrobial activity. Out of the 7 pyrazole compounds tested for antibacterial and antifungal activity, 5 compounds, 4h, 4j, 4l, 4m and 4n are turned out to be potent antimicrobial agents. Therefore these derivatives could serve as a highly promising molecules for further development.
- Nagendra Chowdary,Umashankara,Dinesh,Girish,Ramesha Baba
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- Copper-Promoted Oxidative Intramolecular C–H Amination of Hydrazones to Synthesize 1H-Indazoles and 1H-Pyrazoles Using a Cleavable Directing Group
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A facile and efficient synthesis of 1H-indazoles and 1H-pyrazoles through a copper-promoted oxidative intramolecular C–H amination of hydrazones using a cleavable directing group was developed. This reaction is characterized by its mild conditions, operational simplicity, readily available reagents, and excellent yields. A tentative mechanism for Cu-mediated C–H oxidative amination was proposed.
- Zhang, Guofu,Fan, Qiankun,Zhao, Yiyong,Ding, Chengrong
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supporting information
p. 5801 - 5806
(2019/08/02)
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- Design and synthesis of novel natural clinoptilolite-MnFe2O4 nanocomposites and their catalytic application in the facile and efficient synthesis of chalcone derivatives through Claisen-Schmidt reaction
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A series of three novel nanocomposites were prepared by modifying the surface of natural clinoptilolite using various amounts of manganese ferrite (MnFe2O4) nanoparticles. These manganese ferrite-modified nanocomposites (MFO–NC) were fully characterized by XRD, FT-IR, EDX, VSM and TEM analyses. One of these novel nanocomposites with 40?wt% of manganese ferrite in clinoptilolite (MFO–NC-3) showed a strong catalytic behavior in the aldol-type Claisen–Schmidt reaction for the synthesis of chalcones. A strong catalytic synergy was observed between nano-MnFe2O4 particles and natural clinoptilolite in the structure of these nanocomposites. The products with a broad range of substituents on the reactants were efficiently obtained under room-temperature conditions within relatively short reaction times with good to excellent yields in the presence of one of the prepared MFO–NC nanocomposites. This nanocomposite also showed a strong stability and substantial reusability in the synthesis of chalcones.
- Aryan, Reza,Mir, Noshin,Beyzaei, Hamid,Kharade, Amin
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p. 4245 - 4258
(2018/03/21)
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- Synthesis and evaluation of modified chalcone based p53 stabilizing agents
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Tumor suppressor protein p53 induces cell cycle arrest and apoptotic cell death in response to various cellular stresses thereby preventing cancer development. Activation and stabilization of p53 through small organic molecules is, therefore, an attractive approach for the treatment of cancers retaining wild-type p53. In this context, a series of nineteen chalcones with various substitution patterns of functional groups including chloro, fluoro, methoxy, nitro, benzyloxy, 4-methyl benzyloxy was prepared using Claisen-Schmidt condensation. The compounds were characterized using NMR, HRMS, IR and melting points. Evaluation of synthesized compounds against human colorectal (HCT116) and breast (CAL-51) cancer cell lines revealed potent antiproliferative activities. Nine compounds displayed GI50 values in the low micromolar to submicromolar range; for example (E)-1-phenyl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (SSE14108) showed GI50 of 0.473 ± 0.043 μM against HCT116 cells. Further analysis of these compounds revealed that (E)-3-(4-chlorophenyl)-1-phenylprop-2-en-1-one (SSE14105) and (E)-3-(4-methoxyphenyl)-1-phenylprop-2-en-1-one (SSE14106) caused rapid (4 and 8-h post-treatment) accumulation of p53 in HCT116 cells similar to its induction by positive control, Nutlin-3. Such activities were absent in 3-(4-methoxyphenyl)propiophenone (SSE14106H2) demonstrating the importance of conjugated ketone for antiproliferative and p53 stabilizing activity of the chalcones. We further evaluated p53 levels in the presence of cycloheximide (CHX) and the results showed that the p53 stabilization was regulated at post-translational level through blockage of its degradation. These chalcones can, therefore, act as fragment leads for further structure optimization to obtain more potent p53 stabilizing agents with enhanced anti-proliferative activities.
- Iftikhar, Sunniya,Khan, Sardraz,Bilal, Aishah,Manzoor, Safia,Abdullah, Muhammad,Emwas, Abdel-Hamid,Sioud, Salim,Gao, Xin,Chotana, Ghayoor Abbas,Faisal, Amir,Saleem, Rahman Shah Zaib
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supporting information
p. 4101 - 4106
(2017/08/22)
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- Synthesis and structure-activity relationships of chalcone derivatives as inhibitors of ovarian cancer cell growth
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Background: Ovarian cancer remains a disease with a poor five year survival rate. As such, novel therapies are needed. Natural chalcones as well as their synthetic derivatives have shown biological activity in a number of areas including the inhibition of cancer cell growth. Objective: To synthesize a library of chalcone derivatives, including novel structures, and determiner the inhibition of ovarian cancer cell growth and Structure-activity-relationships. Methods: The Claisen-Schmidt condensation reaction between substituted acetophenones and aromatic aldehydes was used to produce a series of novel chalcones in moderate to excellent yields and good purity. Cellular proliferation of CA-OV3 cells was measured with a MTS assay. Results: Out of the thirty-four synthesized compounds, eight are new derivatives. The synthesized compounds were characterized by 1H NMR, 13C NMR, and HRMS. Biological evaluation of these β-phenylacrylophenone derivatives in CA-OV3 cells showed interesting antiproliferative activities providing initial structure – activity information. Conclusion: Fourteen of the thirty-four tested compounds showed significant activity, with several showing near complete inhibition of growth at 100 μM. The structure-activity relationships suggest that modification to the A ring is widely tolerated and that electron-donating modifications to the B ring are beneficial to activity. Electron-withdrawing modifications to the B ring did not show inhibition of cell growth.
- Tucker, Zachary D.,Barrios, Francis J.,Krzysiak, Amanda J.
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p. 1259 - 1266
(2017/11/14)
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- Facile epoxidation of α, β-unsaturated ketones with urea-2,2-dihydroperoxypropane as a new oxidant
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Abstract: Various aromatic α, β-unsaturated ketones were successfully transformed into their corresponding epoxides using urea-2,2-dihydroperoxypropane as the oxygen source for the first time. The reactions were carried out under mild alkaline conditions at room temperature in high yields and short reaction times. Graphical Abstract: [Figure not available: see fulltext.]
- Khosravi, Kaveh,Naserifar, Shirin
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p. 323 - 328
(2017/01/10)
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- Metal-Free and Efficient Epoxidation of α,β-Unsaturated Ketones with 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane as a Powerful Solid Oxidant
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1,1,2,2-Tetrahydroperoxy-1,2-diphenylethane was used for the efficient and metal-free epoxidation of various α,β-unsaturated ketones, carried out under mild alkaline conditions at room temperature.
- Khosravi, Kaveh,Naserifar, Shirin,Mahmoudi, Boshra
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p. 683 - 689
(2017/06/19)
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- An eco-friendly synthesis of 2-pyrazoline derivatives catalysed by CeCl 3· 7 H 2O
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Abstract: 1,3,5-triaryl-2-pyrazoline derivatives were synthesised by a condensation reaction between chalcones and phenyl hydrazine using cerium chloride heptahydrate as a catalyst. All these reactions were carried out in ethyl lactate (70%) as a green solvent. Easy and efficient work up, recyclability of solvent and catalyst are the key merits of this protocol. Graphical Abstract:: SYNOPSIS A facile protocol for the synthesis of 1,3,5-triaryl-2-pyrazolines is described. The solvent ethyl lactate, obtained from renewable sources, is biodegradable. The catalyst CeCl 3· 7 H 2O is a water-tolerant Lewis acid with low toxicity. Easy and clean work up, recyclable solvent and catalyst are merits of the protocol. The reaction works well for all systems giving good yields of the desired products.[Figure not available: see fulltext.].
- Bhat, Prabhat,Shridhar, Gomathi,Ladage, Savita,Ravishankar, Lakshmy
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p. 1441 - 1448
(2017/09/25)
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- Revisiting the Juliá-Colonna enantioselective epoxidation: Supramolecular catalysis in water
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We describe an efficient epoxidation process leading to chiral epoxyketones using the reusable homo-oligopeptide poly-l-leucine (PLL) in pure water, without any organic co-solvent. A range of substituted epoxyketones can be accessed with good conversions and high enantioselectivities. Based on the experimental results and computational studies, we propose a mechanism that demonstrates the importance of both the α-helical structure and the presence of a hydrophobic groove of the homo-oligopeptide catalyst for reactivity and selectivity.
- Bérubé, Christopher,Barbeau, Xavier,Lagüe, Patrick,Voyer, Normand
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supporting information
p. 5099 - 5102
(2017/07/12)
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- Synthesis and anti-inflammatory activity of new (5 (Substituted Phenyl)-2,3-Dihydro-3-Phenylpyrazol-1-Yl) (Pyridin-3-Yl)methanone derivatives
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A series of 5 (substituted phenyl)-2,3-dihydro-3-phenylpyrazol-1-yl) (pyridin-3-yl)methanone derivatives (2a-h) has been synthesized starting from acetophenone. All the synthesized compounds were evaluated for anti-inflammatory activity using carrageenan-induced inflammation in rat paw edema model. Substituted chalcone derivatives (1a-h) on treatment with isoniazid in the presence of glacial acetic acid afforded corresponding pyrazoline derivatives (2a-h). The structure of the final analogs has been confirmed on the basis of elemental analysis, Fourier transform infrared (FTIR), nuclear magnetic resonance (1H NMR), and mass spectra. Among all synthesized compounds, compounds 2c and 2b were found to be most potent in comparison with standard diclofenac. In addition, the compounds 2c and 2b were found to be less ulcerogenic.
- Tabassum, Ruby,Mohammad, Noor,Kumari, Poonam,Bharatia, Rakesh,Srivastava, Neha,Yogi, Bhumika,Sinha, Anshuman,Gupta, Sujeet K.
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p. 107 - 112
(2019/01/16)
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- Imidazole-triazine type compound and preparation method and application thereof
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The invention provides an imidazole-triazine type compound which is shown as the formula 3 in the description and a preparation method and application thereof. The method comprises the steps that a triazine compound and an alpha,beta-unsaturated ketone type compound are mixed and added into a solvent, under the existence of a metal copper catalyst and an oxidizing material, the mixed solution is stirred and reacts 5-20 hours under the temperature of 60-150 DEG C, after the reaction is finished, the reacted solution is subjected to post processing, and the imidazole-triazine type compound which is shown as the formula 3 is obtained; the metal copper catalyst is halogenide of the copper or a copper salt; the oxidizing material is a halogen elementary substance. The imidazole-triazine type compound can be applied to prepare antibacterial drugs or antibacterial agents, and the preferred antibacterial drugs are the drugs which inhibit activity of escherichia coli.
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Paragraph 0031; 0032; 0033; 0034; 0035; 0037
(2017/10/06)
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- Applying the designed multiple ligands approach to inhibit dihydrofolate reductase and thioredoxin reductase for anti-proliferative activity
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The development of multi-targeting drugs is currently being explored as an attractive alternative to combination therapy, especially for the treatment of complex diseases such as cancer. Dihydrofolate reductase (DHFR) and thioredoxin reductase (TrxR) are enzymes belonging to two unrelated cellular pathways that are known to contribute towards cancer cell growth and survival. In order to evaluate whether simultaneous inhibition of DHFR and TrxR by dihydrotriazines (DHFR-targeting) and chalcones (TrxR-targeting) may be beneficial, breast MCF-7 and colorectal HCT116 carcinoma cells were treated with combinations of selected dihydrotriazines and chalcones at a 1:1 M ratio. Two combinations demonstrated synergy at low-to-moderate concentrations. Based on this result, four merged dihydrotriazine-chalcone compounds were designed and synthesized. Two compounds, 11a [DHFR IC50 = 56.4 μM, TrxR IC50 (60 min) = 12.6 μM] and 11b [DHFR IC50 = 2.4 μM, TrxR IC50 (60 min) = 10.1 μM], demonstrated in vitro inhibition of DHFR and TrxR. The compounds showed growth inhibitory activity against MCF-7 and HCT116 cells, but lacked cytotoxicity. Molecular docking experiments showed 11b to possess rational binding modes to both the enzymes. In conclusion, this study has not only identified the dihydrotriazine and chalcone scaffolds as good starting points for the development of dual inhibitors of DHFR and TrxR, but also demonstrated the synthetic feasibility of producing a chemical entity that could result in simultaneous inhibition of DHFR and TrxR. Future efforts to improve the antiproliferative profiles of such compounds will look at alternative ways of integrating the two pharmacophoric scaffolds.
- Ng, Hui-Li,Chen, Shangying,Chew, Eng-Hui,Chui, Wai-Keung
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- Rational design, synthesis and in vitro evaluation of allylidene hydrazinecarboximidamide derivatives as BACE-1 inhibitors
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BACE-1 (β-secretase) is considered to be one of the promising targets for treatment of Alzheimer's disease as it catalyzes the rate limiting step of Aβ-42 production. Herein, we report a novel class of allylidene hydrazinecarboximidamide derivatives as moderately potent BACE-1 inhibitors, having aminoguanidine substitution on allyl linker with two aromatic groups on either side. A library of derivatives was designed based on the docking studies, synthesized and evaluated for BACE-1 inhibition in vitro. The designed ligands displayed interactions with the catalytic aspartate dyad through guanidinium functionality. Further, the aromatic rings placed on either side of the linker occupied S1 and S3 active site regions contributing to the activity. These ligands were also predicted to follow Lipinski rule and cross blood brain barrier. Compound 2.21, having high docking score, was found to be most active with IC50 of 6.423 μM indicating good correlation with docking prediction.
- Jain, Priti,Wadhwa, Pankaj K.,Rohilla, Shilpa,Jadhav, Hemant R.
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supporting information
p. 33 - 37
(2015/12/18)
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- 2-Oxindole Acts as a Synthon of 2-Aminobenzoyl Anion in the K2CO3-Catalyzed Reaction with Enones: Preparation of 1,4-Diketones Bearing an Amino Group and Their Further Transformations
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A convenient approach for the synthesis of 1,4-diketones bearing an amino group has been developed through the K2CO3-catalyzed reaction of 2-oxindoles with enones with the assistance of atmospheric O2 via sequential Michael addition-oxidation-ring-cleavage process. The further intramolecular reaction leads to the formation of benzoazepinone, quinoline, and 3-oxindole derivatives.
- Miao, Chun-Bao,Zeng, Yu-Mei,Shi, Tong,Liu, Rui,Wei, Peng-Fei,Sun, Xiao-Qiang,Yang, Hai-Tao
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- Iron(III) phthalocyanine chloride-catalyzed oxidation-aromatization of α,β-unsaturated ketones with hydrazine hydrate: Synthesis of 3,5-disubstituted 1H-pyrazoles
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We have developed an iron(III) phthalocyanine chloride-catalyzed oxidation-aromatization of α,β-unsaturated ketones with hydrazine hydrate. Various 3,5-disubstituted 1H-pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room-temperature conditions, short reaction time, high yields, simple work-up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.
- Zhao, Junlong,Qiu, Jun,Gou, Xiaofeng,Hua, Chengwen,Chen, Bang
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p. 571 - 578
(2016/04/20)
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- Phosphorous Acid Promoted Hydration-Condensation of Aromatic Alkynes with Aldehydes Affording Chalcones in an Oil/Water Two-Phase System
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A simple and environmentally benign method was developed for the synthesis of chalcones in high to excellent yields by a phosphorous acid promoted alkyne-aldehyde hydration-condensation in an oil/water two-phase system. The method is the first efficient protocol for the preparation of chalcones that is mediated by a simple Bronsted acid in a two-phase system.
- Zhou, Yongbo,Li, Zhongwen,Yang, Xiao,Chen, Xiulin,Li, Mei,Chen, Tieqiao,Yin, Shuang-Feng
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p. 231 - 237
(2016/01/12)
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- Iron-facilitated oxidative radical decarboxylative cross-coupling between α-oxocarboxylic acids and acrylic acids: An approach to α,β-unsaturated carbonyls
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The first Fe-facilitated decarboxylative cross-coupling reaction between α-oxocarboxylic acids and acrylic acids in aqueous solution has been developed. This transformation is characterized by its wide substrate scope and good functional group compatibility utilizing inexpensive and easily accessible reagents, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyls frequently found in bioactive compounds. The synthetic potential of the coupled products is also demonstrated in subsequent functionalization reactions. Preliminary mechanism studies suggest that a free radical pathway is involved in this process: the generation of an acyl radical from α-oxocarboxylic acid via the excision of carbon dioxide followed by the addition of an acyl radical to the α-position of the double bond in acrylic acid then delivers the α,β-unsaturated carbonyl adduct through the extrusion of another carbon dioxide.
- Jiang, Qing,Jia, Jing,Xu, Bin,Zhao, An,Guo, Can-Cheng
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p. 3586 - 3596
(2015/04/22)
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- Synthesis and structure investigation of novel pyrimidine-2,4,6-trione derivatives of highly potential biological activity as anti-diabetic agent
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Abstract Synthesis of (±)-1,3-dimethyl-5-(1-(3-nitrophenyl)-3-oxo-3-phenylpropyl)pyrimidine-2,4,6(1H,3H,5H)-trione (3) is reported. The structure of compound 3 was deduced by using spectroscopic methods, X-ray crystallography, and DFT calculations. The calculated geometric parameters were found to be in good agreement with the experimental data obtained from the X-ray structure. The NBO calculations were performed to predict the natural atomic charges at the different atomic sites and to study the different intramolecular charge transfer (ICT) interactions. The high LP(3)O6 →z BD?(2)O5-N3 ICT interaction energy (165.36 kcal/mol) indicated very strong n → π?electron delocalization while the small LP(2)O → BD?(1)C-H ICT interaction energies indicated that the C-H ... O intramolecular interactions are weak. The 1H and 13C NMR chemical shifts calculated using GIAO method showed good agreement with the experimental data. The calculated electronic spectra of the studied compound using TD-DFT method showed intense electronic transition band at 243.9 nm (f = 0.2319) and a shoulder at 260.2 nm (f = 0.1483) which were due to H-4/H-2/H-1/H → L+2 and H-5 → L electronic excitations, respectively. Compound 3 (IC50 = 305 ± 3.8 μM) was identified as a potent inhibitor of α-glucosidase in vitro and showed several fold more inhibition than the standard drug acarbose (IC50 = 841 ± 1.73 μM). Molecular docking of the synthesized compound was discussed.
- Barakat, Assem,Soliman, Saied M.,Al-Majid, Abdullah Mohammed,Lotfy, Gehad,Ghabbour, Hazem A.,Fun, Hoong-Kun,Yousuf, Sammer,Choudhary, M. Iqbal,Wadood, Abdul
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p. 365 - 376
(2015/06/30)
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- Synthesis, analgesic and anti-inflammatory activities of chalconyl-incorporated hydrazone derivatives of mefenamic acid
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A series of chalconyl-incorporated hydrazone derivatives of mefenamic acid was synthesized in order to obtain new compounds with potential analgesic and anti-inflammatory activity having lesser side effects. The structures of all synthesized compounds were confirmed by means of elemental analysis, IR, 1H NMR, 13C NMR and mass spectra. All compounds were evaluated for their analgesic and anti-inflammatory activities by tail-flick method and carrageenan-induced rat paw edema test, respectively. Among all the synthesized compounds, compounds (4a) and (4j) exhibited the most prominent and consistent anti-inflammatory activity. In acute ulcerogenicity study, it can be concluded that compounds (4a) and (4j) are devoid of the deadlier gastrointestinal toxicities.
- Kumar, Neeraj,Chauhan, Lalit Singh,Sharma, Chandra Shekhar,Dashora, Nipun,Bera, Rajendra
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p. 2580 - 2590
(2015/02/05)
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- Synthesis of new pyrazolyl-1,3-diazabicyclo[3.1.0]hexe-3-ene derivatives
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A series of new of photochromic 1,3-diazabicyclo[3.1.0]hex-3-ene derivatives based on the skeleton of five-membered pyrazole moiety have been synthesized and characterized by spectral techniques, as well as their photochromic properties were examined under UV light irradiation in various solutions. All these newly synthesized compounds showed good photochromic properties in the both solution and solid states. The UV-Visible spectral analysis of the corresponding pyrazolyl bicyclic aziridines established structure-photochromic behavior relationships.
- Kiyani, Hamzeh,Albooyeh, Fereshteh,Fallahnezhad, Saied
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p. 163 - 169
(2015/03/30)
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- Graphene oxide nanosheets: A highly efficient and reusable carbocatalyst catalyzes the Michael-cyclization reactions of 4-hydroxycoumarins, 4-hydroxypyrone and 4-hydroxy-1-methylquinolinone with chalcone derivatives in aqueous media
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Graphene oxide nanosheets were found to be a highly efficient, reusable and cost-effective carbocatalyst for the facile synthesis of highly diversified 4H-pyrans via a one-pot, two-component condensation reaction between freshly prepared chalcones and 4-hydroxycoumarin in aqueous media offering excellent yields. The new, green and metal free synthetic method also enables the condensation reaction for the formation of a library of pyranoquinolines and pyranopyrans.
- Kausar, Nazia,Ghosh, Partha Pratim,Pal, Gargi,Das, Asish R.
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p. 60199 - 60207
(2015/07/27)
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- Synthesis of new ferrocenyl 1,3-diazabicyclo[3.1.0]hex-3-ene derivatives
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In this work, several new derivatives of ferrocenyl bicylic aziridine photochromic compounds have been prepared from the premade ketoaziridines and ferrocene carboxaldehyde in the presence of ammonium acetate in absolute ethanol via one-pot, three-component reaction. The structures of the newly synthesized compounds were established on the basis of IR, NMR and UV-Vis spectral studies. The newly synthesized compounds exhibit interesting photochromic behavior in the solid phase and solution state. The photochromic behavior of the prepared compounds has been investigated by UV-Visible spectral data.
- Kiyani, Hamzeh,Fallahnezhad, Saied,Albooyeh, Fereshteh
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p. 168 - 175
(2015/06/23)
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- Montmorillonite clay-promoted, solvent-free cross-aldol condensations under focused microwave irradiation
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An environmentally benign, clean and general protocol was developed for the synthesis of aryl and heteroaryl trans-chalcones. This method involved solvent-free reaction conditions under microwave irradiation in the presence of a clay-based catalyst, and afforded the target compounds in good yields and short reaction times. Furthermore, the same conditions allowed the synthesis of symmetrical, diarylmethylene-a,a-unsaturated ketones from aromatic aldehydes and ketones.
- Rocchi, Damiano,Gonzalez, Juan F.,Menendez, J. Carlos
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supporting information
p. 7317 - 7326
(2014/07/08)
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- Nano titania-supported sulfonic acid: An efficient and reusable catalyst for a range of organic reactions under solvent free conditions
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Nano titania-supported sulfonic acid (n-TSA) has been easily prepared from the reaction of nano titania (titanium oxide) with chlorosulfonic acid as sulfonating agent and characterized by the FT-IR spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). The catalytic activity of n-TSA was investigated in the synthesis of important organic derivatives such as pyrimidones, benzothiazoles and chalcones. All of the reactions are very fast and the yields are good to excellent. The catalyst was easily separated and reused for several runs without appreciable loss of its catalytic activity.
- Rahmani, Salman,Amoozadeh, Ali,Kolvari, Eskandar
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p. 184 - 188
(2014/11/08)
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- Antioxidant and antimicrobial studies on fused-ring pyrazolones and isoxazolones
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A series of 3-nitrochalcones have been synthesized enroute towards fused ring pyrazolones and isoxazolones. Base catalyzed condensation of the chalcones with ethylacetoacetate yielded cyclohexenones in good yields (74-76%). The treatment of cyclohexenones with hydrazine hydrate or hydroxylamine chloride in the presence of a base afforded the corresponding fused-ring pyrazolinones (70-78% yield) and isoxazolinones (58-66% yield). The newly synthesized compounds were characterized by IR, 1D and 2D NMR and HRMS spectral analysis. The compounds were screened for their antioxidant and antimicrobial activities. Pyrazolinones showed good DPPH radical scavenging and iron metal chelating properties. The para-hydroxy group was important for a compound to have enhanced antioxidant activity. Pyrazolinones and isoxazolinone exhibited a wider range of antimicrobial activities compared to cyclohexenones. Pyrazolinones and isoxazolinone bearing a thiophene ring were the most potent type of compounds against Bacillus subtilis and Candida albicans with MIC values of 0.313-1.25 μg/mL. Some of the synthesized compounds were found to have promising antioxidant, metal chelation and antimicrobial activities.
- Mazimba, Ofentse,Wale, Kabo,Loeto, Daniel,Kwape, Tebogo
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p. 6564 - 6569
(2015/02/19)
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- An efficient simple one-pot synthesis, characterization and structural studies of some 1,2,3,5-tetraarylpentane-1,5-diones
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A series of 1,2,3,5-tetraarylpentane-1,5-diones (9-23) were synthesised by simple one-pot method and characterized by FT-IR, 1H NMR, 13C NMR and mass spectral techniques. The structure of 3-(4-fluorophenyl)-1,2,5-triphenylpentane-1,5-dione (10) was determined by single crystal X-ray diffraction analysis. The compound 10 crystallize in monoclinic crystal system, in C2/c space group. The torsional angle between the two keto groups was found to be -29.50. The C(23)C(22)C(15)C(8)C(7) chain is almost planar with "W" conformation and observed maximum deviation is 0.122 ? for C(15) from the C(23)/C(22)/C(15)/C(8)/C(7) plane.
- Senthilkumar,Neelakandan,Manikandan
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- Two expedient 'one-pot' methods for synthesis of β-aryl-β- mercaptoketones over anhydrous potassium carbonate or amberlyst-15 catalyst
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Two expedient one-pot methods have been developed for synthesis of β-aryl-β-mercaptoketones using acetophenones, benzaldehydes and thiols as starting materials. The methods involve microwave irradiation (5min) of 1:1 mixtures of acetophenones and benzaldehydes over neutral alumina supported anhydrous potassium carbonate or amberlyst-15 in the first step, and that is followed by addition of thiol to the resulting material and keeping at room temperature for 1.5 h. Indian Academy of Sciences.
- Guha, Chayan,Mondal, Rina,Pal, Rammohan,Mallik, Asok K.
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p. 1463 - 1470
(2014/04/03)
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- Stereo-controlled deamination of ketoaziridines using Ph3P, I2
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Ph3P, I2is an efficient reagent for the stereo-controlled deamination of non-activated aziridines, N-H and N-alkyl aziridines, using. The method works gives the corresponding trans-alkenes from both cis and trans-aziridines. A plausible mechanism is proposed for the ring opening and deamination of keto-aziridines in the presence of Ph3P, I2.
- Samimi, Heshmat Allah,Kiyani, Hamzeh,Shams, Zahra
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p. 282 - 284
(2013/07/27)
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- Solvent-free selective cross-aldol condensation of ketones with aromatic aldehydes efficiently catalyzed by a reusable supported acidic ionic liquid
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A newly prepared catalyst consisting of acidic ionic liquid 1-(4-sulfonic acid) butylpyridinium hydrogen sulfate supported on silica was used to catalyze the cross-aldol condensation of ketones with aromatic aldehydes under solvent-free conditions. The highly active and selective catalyst gave good to excellent yields of the desired cross-aldol products without the occurrence of any self-condensation reactions. Reaction times were short, the procedure and work-up were simple, and no volatile or hazardous organic solvents were necessary. Moreover, the catalyst could be reused at least four times with only a slight reduction in activity.
- Davoodnia, Abolghasem,Yassaghi, Ghazaleh
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p. 1950 - 1957
(2013/02/25)
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- A simple and efficient method for the allylation of heteroarenes catalyzed by PdCl2
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The PdCl2-catalyzed allylation of heteroarenes is presented. Various heteroarenes including O-, N-, and S-based ones were allylated efficiently with a rich range of allylic acetates in the presence of only 2 mol % of PdCl2, without the need of bases/acids, additives, and external supporting ligands. In addition, the reactions were carried out under mild and simple conditions just by stirring the two reactants and catalyst in CH 2Cl2 at 60 °C. Moreover, the by-product produced was non-toxic acetic acid. Thus, the method presented in this work provides a general, clean, and operationally simple approach for the functionalization of heteroarenes. Finally, a preliminary mechanistic study suggested that the Pd(II) may be reduced in situ by the heteroarenes to Pd(0), which serves as the active metal center to catalyze the following allylations of heteroarenes via a Tsuji-Trost pathway.
- Yuan, Feng-Quan,Sun, Feng-Yi,Han, Fu-She
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scheme or table
p. 6837 - 6842
(2012/08/28)
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- Silicotungstic acid catalysed Claisen Schmidt condensation reaction: An efficient protocol for synthesis of 1,3-diaryl-2-propenones
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An efficient and clean synthesis of 1,3-diaryl-2-propenones has been carried out by Claisen Schmidt condensation reaction of aryl methyl ketones with a series of aromatic aldehydes at room temperature in the presence of the catalyst silicotungstic acid (STA). This method provides an ecofriendly, chemoselective, efficient and green synthesis of 1,3-diaryl-2-propenones in excellent yields.
- Rajput, Jaspreet Kaur,Kaur, Gagandeep
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experimental part
p. 646 - 649
(2012/02/15)
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- Influence of substituent on UV absorption and keto-enol tautomerism equilibrium of dibenzoylmethane derivatives
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UV absorption spectra of dibenzoylmethane and its 23 derivatives with acetamide, tert-butyl, chloride, fluoride, hydroxyl, methyl, methoxy and nitro substituents in aromatic rings were collected. General influence of substituent on absorption maxima and absorption intensity was defined. Hyperchromic effects were observed for diketones with electron-donating groups in para postion. The keto-enol tautomerism equilibrium constant of obtained compounds was investigated with 1H NMR spectroscopy. Significant changes of equilibrium were observed only for ortho substituted compounds. Results revealed dissimilarity of substituent effects on absorption and keto-enol tautomerism of aromatic β-diketones.
- Zawadiak, Jan,Mrzyczek, Marek
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supporting information
p. 815 - 819
(2012/11/13)
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- An efficient direct-aldol addition of methyl ketones with aldehydes promoted by MgI2 etherate
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Direct aldol addition of ketones with aromatic aldehydes and vinyl aldehyde was carried out efficiently in the presence of MgI2 etherate and Et3N using untreated reagent grade CH2Cl2 under atmospheric conditions in a mild, efficient and highly chemoselective manner. Iodide counterion and non-coordinating reaction media (i.e., CH 2Cl2) are among the critical factors for the unique reactivity of this reaction system.
- Liu, Yingshuai,Shen, Hangzhou,Zhang, Xingxian
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p. 111 - 115
(2013/03/13)
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- Deamination of cis and trans-aziridines using diethyl thiourea and iodine
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Various non-activated aziridines reacted with diethyl thiourea in the presence of iodine in DCM to give the corresponding trans-alkenes as a sole product in good to excellent yields. Iranian Chemical Society 2012.
- Samimi, Heshmat A.,Shams, Zahra,Momeni, Ahmad R.
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p. 705 - 708
(2013/02/23)
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- NUCLEAR RECEPTOR MODULATORS AND THEIR USE FOR THE TREATMENT AND PREVENTION OF CANCER
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Disclosed are compounds which are nuclear receptor modulators that can act as antagonists to the androgen receptor, for example, a compound of Formula I: wherein R1 to R5 and X1 to X5 are as described herein, as well as pharmaceutically acceptable salts, solvates, and stereoisomers thereof. Pharmaceutical compositions comprising such compounds, as well as methods of use, and treatment for cancers, including prostate cancers, other nuclear receptor mediated cancers, and other conditions, are also disclosed.
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Page/Page column 23
(2013/02/28)
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- Mosquito larvicidal studies of some chalcone analogues and their derived products: Structure-activity relationship analysis
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A series of chalcone analogues and some of their derivatives were synthesized and subjected to the mosquito larvicidal study. Chalcones having electron releasing group(s) on either ring A or ring B showed high toxicity. Electron withdrawing group(s), especially at ring B, reduced the activity of chalcones. The activity was abruptly decreased due to replacement of ring A by CH3, extension of conjugation or blocking of α,β- unsaturated ketone part of chalcones by derivatization. Quantitative structure-activity relationship (QSAR) studies of these compounds were performed using various spatial, electronic and physicochemical parameters. Genetic Function approximation with linear and spline options was used as the chemometric tool for developing the QSAR models.
- Begum, Naznin A.,Roy, Nayan,Laskar, Rajibul A.,Roy, Kunal
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experimental part
p. 184 - 191
(2012/02/16)
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- Sulfamic acid: An efficient, cost-effective and green catalyst for crossed-aldol condensation of ketones with aromatic aldehydes under solvent-free
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Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α, β-unsaturated aldol products under solvent-free conditions in good to high yields at 45-80 °C.
- Rostami, Amin,Ahmad-Jangi, Firoz
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experimental part
p. 1029 - 1032
(2012/06/01)
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- Phosphine-catalyzed cascade [3 + 2] cyclization-allylic alkylation, [2 + 2 + 1] annulation, and [3 + 2] cyclization reactions between allylic carbonates and enones
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The phosphine-catalyzed annulations between Morita-Baylis-Hillman adduct carbonates and enones are reported. Under the catalysis of PBu3 (20 mol %), cascade [3 + 2] cyclization-allylic alkylation, [2 + 2 + 1] annulation, and [3 + 2] cyclization reactions chemoselectively occur depending on the substituent variation of both the carbonate and enone. These reactions provide efficient syntheses of highly functionalized cyclopentenes and cyclopentanes.
- Zhou, Rong,Wang, Jianfang,Song, Haibin,He, Zhengjie
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supporting information; scheme or table
p. 580 - 583
(2011/04/23)
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- Synthesis, characterization and fluorescence studies of 3,5-diaryl substituted 2-pyrazolines
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A series of 2-pyrazolines have been synthesized from α, β unsaturated ketones and hydrazine hydrate with acetic/formic acid in ethanol/DMSO. The structures of 2-pyrazolines have been established by spectroscopic techniques i.e. UV, IR, 1H NMR, 13C NMR and micro element analysis. Fluorescence spectra were recorded in the solution at fixed concentration and same excitation wavelength at 290 nm. The absorption band positions of all the compounds broadly lie between 280 and 336 nm and fluorescence band positions in the range between 300 and 370 nm, the near ultraviolet region.
- Nee Pant, Geeta Joshi,Singh, Pramod,Rawat,Rawat,Joshi
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scheme or table
p. 1075 - 1079
(2011/04/16)
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