- Solvent influence on excited-state intramolecular proton transfer in 3-hydroxychromone derivatives studied by cryogenic high-resolution fluorescence spectroscopy
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High-resolution Shpol'skii spectra (recorded at 10 K in n-octane) of 3-hydroxychromone (3HC) substituted at the 2-position with a furan (3HC-F), a benzofuran (3HC-BF) or a naphthofuran group (3HC-NF) are presented. Being close analogues of 3-hydroxyflavone (3HF), these compounds can undergo excited-state intramolecular proton transfer (ESIPT). Luminescence can occur from the normal N* state (blue) or from the tautomeric T* state (green). Whether blue or green emission is observed is strongly dependent on hydrogen-bonding interactions with the environment. For all three chromones studied, high-resolution emission spectra in the green region (T*→T) were obtained in pure n-octane, showing four sites with distinct emission bands and detailed vibrational structures, whereas no blue emission was detected. Contrary to the spectra published for 3HF, the emission lines were very narrow (line-broadening effects beyond detection) which implies that the ESIPT rate constants are >1012 s-1, at least 25 times lower than for 3HF. In order to study the effects of hydrogen-bonding solvents, four isomers of octanol (1-, 2-, 3- and 4-octanol) were added, forming 1:1 complexes with the 3HC derivatives. For all the combinations considered both blue and additional green emission was observed and in some cases narrow-banded spectra were obtained, mostly in the green. Only for the 3HC-NF/2-octanol complex, narrow-banded emission was found both in the blue and in the green region. It is demonstrated that these emissions come from different configurations of the complex. Possible structures for the two complex species are proposed, supported by semi-empirical calculations on complex formation enthalpies.
- Bader, Arjen N.,Pivovarenko, Vasyl,Demchenko, Alexander P.,Ariese, Freek,Gooijer, Cees
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Read Online
- Thallium(III) p-tosylate-mediated oxidative [1,2] rearrangement of 2-naphthyl and 2-heteroarylchromanones
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A practical and effective approach towards the synthesis of 3-heteroaryl-4H-chromen-4-ones by the oxidative [1,2] rearrangement of the respective 2-heteroaryl chroman-4-ones using thallium(III) p-tosylate is presented. The oxidative rearrangement of α- an
- Kurapati, Chidvilas,Muthukrishnan, Murugan,Singh, Om V.,Gundla, Rambabu
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supporting information
p. 172 - 177
(2021/10/29)
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- Water stable fluorescent organotin(iv) compounds: aggregation induced emission enhancement and recognition of lead ions in an aqueous system
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Herein, synthesis, spectroscopic studies, single-crystal X-ray diffraction, aggregation-induced emission enhancement (AIEE) and sensing application of water-stable organotin(iv) compounds (4a-6aand4b-6b) obtained from 3-hydroxy-4H-chromen-4-one ligands are reported. All the synthesized organotin(iv) compounds were characterized using elemental analysis, FT-IR spectroscopy, multi-nuclei NMR (1H,13C, and119Sn) spectroscopy, UV-VIS, fluorescence spectroscopy, mass spectrometry, and single-crystal X-ray diffraction. The119Sn NMR signal of compounds in the range ofδ?144.92 to ?190.68 ppm indicated the formation of hexacoordinated organotin species. The spectroscopic and single-crystal X-ray diffraction studies confirmed the formation of [L2SnR2] type compounds (where L is the bidentate ligand and R is an alkyl group) with a ‘skew-trapezoidal bipyramidal’ geometry. Furthermore, DFT calculations of compound4bbased on the DGDZVP basis set fully supported the stability of the structure where two short bonds Sn-O(C-O)acquire thecisposition rather than thetransposition. Single-crystal X-ray diffraction analysis of the crystals grown in the presence of water confirmed the stability of4ain water. Moreover, the water stability of a test compound4awas established by119Sn NMR data and spectrofluorimetric data. The spectrofluorimetric scan at different time intervals revealed the stability and constant emission response up to 24 h. The compounds were found to be fluorescent and exhibited aggregation-induced emission enhancement in MeOH/H2O mixtures, which was confirmed by HRTEM analysis. The test compound4ashowed selective spectrofluorimetric recognition of Pb2+ions in an aqueous medium by displaying an enhanced emission signal at 478 nm and enabled detection up to 22.66 μM. A mechanism of interaction is also proposed by spectroscopic experiments, spectrofluorimetric experiments and computational studies.
- Capalash, Neena,Kaur, Kulwinder,Kaur, Varinder,Singh, Raghubir
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p. 148 - 161
(2021/12/31)
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- Convenient synthesis of flavanone derivatives via oxa-Michael addition using catalytic amount of aqueous cesium fluoride
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A total of 36 flavanones, which included polycyclic aromatic and heterocyclic rings, were readily synthesized via oxa-Michael addition from the corresponding hydroxychalcones with a catalytic amount of aqueous cesium fluoride solution under mild conditions. This method could be applied to the scalable synthesis of eriodictyol as a known potent inhibitor of the SARS-CoV-2 spike protein.
- Miura, Motofumi,Shigematsu, Karin,Toriyama, Masaharu,Motohashi, Shigeyasu
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supporting information
(2021/10/25)
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- Synthetic Aurones: New Features for Schistosoma mansoni Therapy
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In this work, two synthetic aurones revealed moderate schistosomicidal potential in in vitro and in vivo assays. Aurones (1) and (2) promoted changes in tegument integrity and motor activity, leading to death of adult Schistosoma mansoni worms in in vitro
- Alves da Silva Filho, Ademar,Alves de Oliveira, Bruna,Azevedo Alves, Lara,Fortini Grenfell e Queiroz, Rafaella,Gomes Vasconcelos, Eveline,Paulo da Silva, Marcos,Silva Torres, Daniel,Vanessa Zabala Capriles Goliatt, Priscila,de Faria Pinto, Priscila,Carius de Souza, Vinícius,Martins Parreiras, Patrícia,Moraes, Josué,Rúbia Costa Couri, Mara,Roberto Silva, Márcio,Rodrigues Dur?es Pereira, Vinícius,Souza d Silveira, Lígia
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- Spectroscopic analysis by NMR, FT-Raman, ATR-FTIR, and UV-Vis, evaluation of antimicrobial activity, and in silico studies of chalcones derived from 2-hydroxyacetophenone
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Six 2’-hydroxychalcones were synthesized and characterized by NMR, FT-Raman, ATR-FTIR, and UV-Vis. These chalcones alone and in combination with the ciprofloxacin, penicillin, and erythromycin antibiotics were tested against multiresistant strains of Staphylococcus aureus. It was also verified by in vitro and in silico studeis the capacity of these chalcones to inhibit the NorA efflux pump. The MICs values of ciprofloxacin were reduced in the presence of all tested chalcones. For norfloxacin antibiotic, the chalcones A1, A4, A5 and A6 promoted the reduced in the MIC values. The A2 chalcone was the only one to reduce the MIC values when associated with penicillin. Any chalcones were not able to reduce MIC values when associated with erythromycin. These results indicate that the synergistic effects demonstrated for the synthesized chalcones were influenced by the introduction of a furanic ring (A1), a chlorine atom and a methoxy group at the C4 position (A2 and A4), a second double bond (A5), and a fluorine atom at the C2 position (A6). The ADMET analysis predicts that the chalcones A2, A3, A5 and A6 have easier cell permeation. The nucleophilic region makes the A5 chalcone capable of covalently bonding with plasma proteins, and the presence of oxygenated aromatic substitutions makes the chalcones A1 and A4 more water-soluble and consequently easier to excrete. On the other hand, the substitution of the methoxy group of the A4 chalcone makes it more susceptible to O-demethylation reactions by the CYP3A4 isoenzyme. The molecular docking revealed that all six chalcones could hinder the binding of norfloxacin to the NorA efflux pump.
- Xavier, Jayze da Cunha,de Almeida-Neto, Francisco W.Q.,Rocha, Janaína E.,Freitas, Thiago S.,Freitas, Priscila R.,de Araújo, Ana C.J.,da Silva, Priscila T.,Nogueira, Carlos E.S.,Bandeira, Paulo N.,Marinho, Márcia M.,Marinho, Emmanuel S.,Kumar, Nitin,Barreto, Ant?nio C.H.,Coutinho, Henrique D.M.,Juli?o, Murilo S.S.,dos Santos, Hélcio S.,Teixeira, Alexandre M.R.
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- A novel one-pot synthesis of flavones
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In this paper, a one-pot facile route for the BiCl3/RuCl3-mediated synthesis of functionalized flavones is described, including: (i) intermolecularortho-acylation of substituted phenols with cinnamoyl chlorides, and (ii) intramolecular cyclodehydrogenation of the resultingo-hydroxychalcones. The reaction conditions are discussed herein.
- Chang, Meng-Yang,Tsai, Min-Chen,Lin, Chun-Yi
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p. 11655 - 11662
(2021/03/31)
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- Exploring 3-hydroxyflavone scaffolds as mushroom tyrosinase inhibitors: synthesis, X-ray crystallography, antimicrobial, fluorescence behaviour, structure-activity relationship and molecular modelling studies
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To explore new scaffolds as tyrosinase enzyme inhibitors remain an interesting goal in the drug discovery and development. In due course and our approach to synthesize bioactive compounds, a series of varyingly substituted 3-hydroxyflavone derivatives (1-23) were synthesized in one-pot reaction and screened for in?vitro against mushroom tyrosinase enzyme. The structures of newly synthesized compounds were unambiguously corroborated by usual spectroscopic techniques (FTIR, UV-Vis, 1H-, 13C-NMR) and mass spectrometry (EI-MS). The structure of compound 15 was also characterized by X-ray diffraction analysis. Furthermore, the synthesized compounds (1-23) were evaluated for their antimicrobial potential. Biological studies exhibit pretty good activity against most of the bacterial-fungal strains and their activity is comparable to those of commercially available antibiotics i.e. Cefixime and Clotrimazole. Amongst the series, the compounds 2, 4, 5, 6, 7, 10, 11, 14 and 22 exhibited excellent inhibitory activity against tyrosinase, even better than standard compound. Remarkably, the compound 2 (IC50 = 0.280 ± 0.010 μg/ml) was found almost sixfold and derivative 5 (IC50 = 0.230 ± 0.020 μg/ml) about sevenfold more active as compared to standard Kojic acid (IC50 =1.79 ± 0.6 μg/ml). Moreover, these synthetic compounds (1-23) displayed good to moderate activities against tested bacterial and fungal strains. Their emission behavior was also investigated in order to know their potential as fluorescent probes. The molecular modelling simulations were also performed to explore their binding interactions with active sites of the tyrosinase enzyme. Limited structure-activity relationship was established to design and develop new tyrosinase inhibitors by employing 2-arylchromone as a structural core in the future. Communicated by Ramaswamy H. Sarma.
- Ashraf, Jamshaid,Mughal, Ehsan Ullah,Sadiq, Amina,Bibi, Maryam,Naeem, Nafeesa,Ali, Anser,Massadaq, Anam,Fatima, Nighat,Javid, Asif,Zafar, Muhammad Naveed,Khan, Bilal Ahmad,Nazar, Muhammad Faizan,Mumtaz, Amara,Tahir, Muhammad Nawaz,Mirzaei, Masoud
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p. 7107 - 7122
(2020/08/21)
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- Glycolytic inhibition and antidiabetic activity on synthesized flavanone scaffolds with computer aided drug designing tools
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Background: Diabetes mellitus is a challengeable metabolic disorder that leads to a group of complications when the HbA1c level is not maintained. Most of the existing drugs avail-able in the market in long-term use may lead to serious adverse effects. He
- Kiruthiga, Natarajan,Saravanan, Govindaraj,Selvinthanuja, Chellappa,Sivakumar, Thangavel,Srinivasan, Kulandaivel
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p. 574 - 592
(2021/09/30)
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- Biocatalytic green alternative to existing hazardous reaction media: Synthesis of chalcone and flavone derivatives via the Claisen-Schmidt reaction at room temperature
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Owing to the increasing amount of waste materials around the globe, the conversion of waste or secondary by-products to value-added products for various applications has gained significant interest. Herein, two novel agro-food waste products, Musa sp. 'Malbhog' peel ash (MMPA) and Musa Champa Hort. ex Hook. F. peel ash (MCPA) are used as catalysts to promote an inexpensive, efficient and eco-friendly carbon-carbon bond forming crossed aldol reaction at room temperature in solvent free conditions. Furthermore, the resulting products were subjected to reactions with these promoters in an oxygen atmosphere and led to the formation of novel flavone derivatives. Moreover, the used catalysts were properly characterized using different sophisticated analytical techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller analysis (BET), Raman spectroscopy, scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), transition electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) along with element detection using atomic absorption spectroscopy and ion chromatographic methods. These two approaches are metal free, as well as being devoid of any extra additives, co-catalysts, harsh conditions, the use of column chromatography for purification and result in a higher yield of the product within a short space of time. The catalytic abilities of the promoter were also examined to synthesize important bioactive molecules such as butein and apigenin at room temperature. With gram scale synthesis of the chalcone derivatives, the used catalysts (MMPA and MCPA) were further reused for five cycles and did not demonstrate any loss in catalytic activity.
- Tamuli, Kashyap J.,Sahoo, Ranjan K.,Bordoloi, Manobjyoti
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supporting information
p. 20956 - 20965
(2020/12/31)
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- Synthesis and antibacterial activity of chalcone derivatives containing thioether triazole
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The infection of Xanthomonas oryzae pv. Oryzae (Xoo), Ralstonia solanacearum (Rs), and Xanthomonas axonopodis pv. Citri (Xac) has become a major problem in agricultural production. In this study, a series of novel chalcone derivatives containing thioether triazoles were designed and synthesized. The structures of the novel compounds were systematically characterized via 1H-NMR, 13C-NMR, and HRMS. Moreover, the antibacterial activity results showed that E10, E11, E15, and E16 have adequate antibacterial activities against Xoo, Rs, and Xac. Among the different compounds, E15 exhibited remarkable inhibitory effect against Xac with an EC50 of 9.1 μg.mL-1, which was better than that of commercial agent bismerthiazol (54.9 μg.mL-1). In addition, the possible antibacterial mechanism of the target compound E15 against Xac was studied via scanning electron microscopy (SEM).
- Chen, Mei,Chen, Ying,He, Jun,He, Ming,Li, Pu,Su, Shijun,Wang, Hua,Xue, Wei
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- Novel chalcone and flavone derivatives as selective and dual inhibitors of the transport proteins ABCB1 and ABCG2
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During cancer chemotherapy, certain cancers may become cross-resistant to structurally diverse antineoplastic agents. This so-called multidrug resistance (MDR) is highly associated with the overexpression of ATP-binding cassette (ABC) transport proteins. These membrane-bound efflux pumps export a broad range of structurally diverse endo- and xenobiotics, including chemically unrelated anticancer agents. This translocation of drugs from the inside to the outside of cancer cells is mediated at the expense of ATP. In the last 40 years, three ABC transporters – ABCB1 (P-gp), ABCC1 (MRP1), and ABCG2 (BCRP) – have mainly been attributed to the occurrence of MDR in cancer cells. One of the strategies to overcome MDR is to inhibit the efflux transporter function by small-molecule inhibitors. In this work, we investigated new chalcone- and flavone-based compounds for selective as well as broad-spectrum inhibition of the stated transport proteins. These include substituted chalcones with variations at rings A and B, and flavones with acetamido linker at position 3. The synthesized molecules were evaluated for their inhibitory potential against ABCB1, ABCC1, and ABCG2 in calcein AM and pheophorbide A assays. In further investigations with the most promising candidates from each class, we proved that ABCB1- and ABCG2-mediated MDR could be reversed by the compounds. Moreover, their intrinsic toxicity was found to be negligible in most cases. Altogether, our findings contribute to the understanding of ABC transport proteins and reveal new compounds for ongoing evaluation in the field of ABC transporter-mediated MDR.
- Silbermann, Katja,Shah, Chetan P.,Sahu, Niteshkumar U.,Juvale, Kapil,Stefan, Sven Marcel,Kharkar, Prashant S.,Wiese, Michael
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p. 193 - 213
(2019/01/03)
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- Design, synthesis, and biological evaluation of Helicobacter pylori inosine 5′-monophosphate dehydrogenase (HpIMPDH) inhibitors
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Inosine 5′-monophosphate dehydrogenase (IMPDH) catalyzes a crucial step in the biosynthesis of guanine nucleotides. Being a validated target for immunosuppressive, antiviral, and anticancer drug development, lately it has been exploited as a promising target for antimicrobial therapy. Extending our previous work on Mycobacterium tuberculosis IMPDH, GuaB2, inhibitor development, we screened a set of 23 new chemical entities (NCEs) with substituted flavone (Series 1) and 1,2,3-triazole (Series 2) core structures for their in vitro Helicobacter pylori IMPDH (HpIMPDH) and human IMPDH2 (hIMPDH2) inhibitory activities. All the NCEs possessed acceptable molecular, physicochemical, and toxicity property profiles. The ranges for HpIMPDH and hIMPDH2 inhibition were 9–99.9% and 16–57%, respectively, at 10 μM concentration. The most potent HpIMPDH inhibitor, 25c, exhibited IC50 value of 1.27 μM with no hIMPDH2 inhibitory activity. The moderately potent, structurally novel hit molecule, 25c, may serve as a lead for further design and development of highly potent HpIMPDH inhibitors.
- Sahu, Niteshkumar U.,Purushothaman, Gayathri,Thiruvenkatam, Vijay,Kharkar, Prashant S.
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p. 125 - 132
(2018/11/06)
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- Design, synthesis, molecular modelling, and in vitro evaluation of tricyclic coumarins against Trypanosoma cruzi
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Chagas disease is caused by infection with the parasite protozoan Trypanosoma cruzi and affects about 8 million people in 21 countries in Latin America. The main form of treatment of this disease is still based on the use of two drugs, benznidazole and nifurtimox, which both present low cure rates in the chronic phase and often have serious side-effects. Herein, we describe the synthesis of tricyclic coumarins that were obtained via NHC organocatalysis and evaluation of their trypanocidal activity. Molecular docking studies against trypanosomal enzyme triosephosphate isomerase (TIM) were carried out, as well as a theoretical study of the physicochemical parameters. The tricyclic coumarins were tested in vitro against the intracellular forms of Trypanosoma cruzi. Among the 18 compounds tested, 10 were more active than the reference drug benznidazole. The trypanocidal activity of the lead compound was rationalized by molecular docking study which suggested the strong interaction with the enzyme TIM by T.?cruzi and therefore indicating a possible mode of action. Furthermore, the selectivity index of eight tricyclic coumarins with high anti-T.?cruzi activity was above 50 and thus showing that these lead compounds are viable candidates for further in vivo assays.
- Coelho, Gleicekelly Silva,Andrade, Josimara Souza,Xavier, Viviane Flores,Sales Junior, Policarpo Ademar,Rodrigues de Araujo, Barbara Caroline,Fonseca, Kátia da Silva,Caetano, Melissa Soares,Murta, Silvane Maria Fonseca,Vieira, Paula Melo,Carneiro, Claudia Martins,Taylor, Jason Guy
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p. 337 - 350
(2018/12/05)
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- A 2 - hydroxyaroyl oxime compound and its preparation method and application
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The invention relates to a 2 - hydroxyaroyl oxime compound and its preparation method and application. The 2 - hydroxyaroyl oxime compound, structural formula such as formula (I) as shown: Wherein R1 For H, saturated alkyl or bond-containing un
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Paragraph 0055-0058
(2019/07/01)
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- Effective Hydrogenation of 3-(2”-furyl)- And 3-(2”-thienyl)-1-(2’-hydroxyphenyl)-prop-2-en-1-one in Selected Yeast Cultures
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Biotransformations were performed on eight selected yeast strains, all of which were able to selectively hydrogenate the chalcone derivatives 3-(2”-furyl)-(1) and 3-(2”-thienyl)-1-(2’-hydroxyphenyl)-prop-2-en-1-one (3) into 3-(2”-furyl)- (2) and 3-(2”-thi
- ?u zny, Mateusz,Krzywda, Martyna,Koz?owska, Ewa,Kostrzewa-Sus?ow, Edyta,Janeczko, Tomasz
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- Synthesis of 3-HCF2S-Chromones through Tandem Oxa-Michael Addition and Oxidative Difluoromethylthiolation
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A simple protocol for the synthesis of difluoromethylthiolated chromen-4-ones using elemental sulfur and ClCF2CO2Na as the difluoromethylthiolating agent is described. Three-component reactions of 2′-hydroxychalcones, ClCF2CO2Na, and sulfur under basic conditions using TEMPO as the oxidant afforded HCF2S-containing 4H-chromen-4-one and 9H-thieno[3,2-b]chromen-9-one derivatives in good yield. The protocol is practical and efficient, and the starting materials are cheap and readily available.
- Zhang, Pingshun,Chen, Wanzhi,Liu, Miaochang,Wu, Huayue
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supporting information
p. 9326 - 9329
(2019/12/24)
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- Synthesis of a series of chalcones and related flavones and evaluation of their antibacterial and antifungal activities
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Background: A series of chalcones and flavones were synthesized from 2’-hydroxyacetophenone and substituted aromatic aldehydes via Simmons-Schmidt condensation followed by oxidative cyclization. Methods: Characterization of the obtained structures was established on the basis of their spectroscopic data. The synthesized compounds were screened for their antimicrobial activities against five bacterial strains (Citrobacter freundii, Staphylococcus aureus, Listeria monocytogenes, Salmonella braenderup, Escherichia coli.) and two fungal strains (Candida albicans, Candida krusei). Results: The in vitro bioassay results indicated that some target compounds displayed moderate (4d, 4e) to high (4a) antifungal activity against the pathogenic fungi C. albicans and C. krusei. Conclusion: For the antibacterial activity, only products 3d and 4d showed a weak antibacterial activity. These compounds can lead to the design of new drugs with specific antifungal activity.
- Benouda, Hind,Bouchal, Btissam,Challioui, Allal,Oulmidi, Abdelkader,Harit, Tarik,Malek, Fouad,Riahi, Abdelkhalek,Bellaoui, Mohammed,Bouammali, Boufelja
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- From Carbamate to Chalcone: Consecutive Anionic Fries Rearrangement, Anionic Si → C Alkyl Rearrangement, and Claisen-Schmidt Condensation
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A highly efficient one-pot procedure was developed for the synthesis of various 2′-hydroxychalcones from phenyl diethylcarbamate, featuring consecutive Snieckus-Fries rearrangement, anionic Si a?' C alkyl rearrangement, and Claisen-Schmidt condensation in a single operation. The applicability of this protocol was demonstrated by the highly efficient synthesis of the anti-inflammatory natural product lonchocarpin. The mechanism insight is also provided.
- Kumar, Singam Naveen,Bavikar, Suhas Ravindra,Pavan Kumar, Chebolu Naga Sesha Sai,Yu, Isaac Furay,Chein, Rong-Jie
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p. 5362 - 5366
(2018/09/12)
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- Effect of solvent polarity on the photophysical properties of chalcone derivatives
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The absorption and fluorescence characteristics of (E)-3-(furan-2-yl)-1-(4-nitrophenyl)prop-2-en-1-one (FNPO), (E)-1-(4-aminophenyl)-3-(furan-2-yl)prop-2-en-1-one (AFPO) and (E)-3-(furan-2-yl)-1-(2-hydroxyphenyl)prop-2-en-1-one (FHPO) were recorded in eig
- Kumari, Rekha,Varghese, Anitha,George, Louis,Sudhakar
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p. 24204 - 24214
(2017/07/11)
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- Photoreactions of 2-(furan-2-yl)-3-hydroxy-4H-chromen-4-one and 3-hydroxy-2-(thiophene-2-yl)-4 H -chromen-4-one using cyclohexane and acetonitrile as solvents
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Photolysis of the titled chromenones was carried out at their longest absorption band (~360 nm) using cyclohexane (CH) and acetonitrile (ACN) as solvents, in both aerated and de-aerated solutions. Different dimeric photoproducts were formed with both chromenones in aerated solutions. On photolysing 2-(furan-2-yl)-3-hydroxy-4H-chromen-4-one (FHC) in aerated cyclohexane, 2-(furan-2-yl)-2-{[2-(furan-2yl)-4-oxo-4H-chromen-3-yl]oxy}-2H-chromene-3,4-dione (a dehydrodimer) was formed, and on photolysing 3-hydroxy-2-(thiophene-2-yl)-4H-chromen-4-one (THC) in aerated ACN, a different dimeric product was isolated and identified. The corresponding 3-aryl-3-hydroxy-1,2-indandiones were also detected with FHC in ACN and with THC in CH, in addition to the dimeric products in both cases. On the other hand, in the de-aerated solutions, only the corresponding 1,2-indandiones were detected. 3-(Furan-2-yl)isobenzofuran-1(3H)-one as a secondary product was also detected with FHC in both solvents. An attempt was made to isolate the spectra of the photoproducts in situ. Excited State Intramolecular Proton Transfer (ESIPT) and Excited State Intramolecular Charge Transfer (ESICT) processes complicate the photodynamics of the reaction, making it difficult to predict the mechanisms of the photoreactions. However, tentative mechanisms have been proposed for the formation of the photoproducts.
- Kaur, Kulvir,Kaur, Ranbir,Tomar, Jyoti,Bansal, Manisha
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p. 1311 - 1319
(2017/08/16)
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- A facile microwave-assisted synthesis of 3-hydroxy-2-phenyl-4H-chromen-4-one and its derivatives via a novel approach
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The presented research work demonstrates a new methodology for generating a petite library of novel flavonol derivatives via Algar-Flynn-Oyamada reaction. Amongst oxygen-containing heterocycles, flavonoids are versatile scaffolds due to their manifestation as crucial components in various natural products and encompassing massive biological activities. Thus, in view of the immense significance of flavonols and the pronounced effect of microwave-assisted protocol, a systematic and efficient scheme is put together for constructing the target motive and its derivatives by both classical and novel method. Initially, 2-hydroxy chalcones are assembled through an innovative conventional technique, later followed by the formation of flavonols. This methodical protocol results in enhanced yield with reduced reaction times under benign and environmental friendly conditions. (Chemical Equation Presented).
- Ehsan, Shahana,Faisal, Saniya,Akbar, Wajiha
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p. 1190 - 1195
(2017/01/25)
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- Extended Aromatic and Heteroaromatic Ring Systems in the Chalcone-Flavanone Molecular Switch Scaffold
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Previous work on the o-hydroxychalcone/flavanone molecular switching scaffold showed that simple substitutions alter the pH range in which rapid interconversion occurs. Herein, more impactful structural modifications were performed via alteration of the characteristic phenyl rings to alternative aromatic systems. It was determined that the scaffold was still viable after these changes and that the range of accessible midpoint pH values was markedly increased. To further explore the switch's scope, scaffolds able to have multiple switching events were also investigated.
- Muller, Brian M.,Litberg, Theodore J.,Yocum, Reid A.,Pniewski, Chanté A.,Adler, Marc J.
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p. 5775 - 5781
(2016/07/13)
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- The synthesis and synergistic antifungal effects of chalcones against drug resistant Candida albicans
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To identify effective and low toxicity synergistic antifungal compounds, 24 derivatives of chalcone were synthesized to restore the effectiveness of fluconazole against fluconazole-resistant Candida albicans. The minimal inhibitory concentration (MIC80) and the fractional inhibitory concentration index (FICI) of the antifungal synergist fluconazole were measured against fluconazole-resistant Candida albicans. This was done via methods established by the clinical and laboratory standards institute (CLSI). Of the synthesized compounds, 2′-hydroxy-4′-methoxychalcone (8) exhibited the most potent in vitro (FICI = 0.007) effects. The structure activity relationship of the compounds are then discussed.
- Wang, Yuan-Hua,Dong, Huai-Huai,Zhao, Fei,Wang, Jie,Yan, Fang,Jiang, Yuan-Ying,Jin, Yong-Sheng
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supporting information
p. 3098 - 3102
(2016/06/13)
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- A new series of 2-phenol-4-aryl-6-chlorophenyl pyridine derivatives as dual topoisomerase I/II inhibitors: Synthesis, biological evaluation and 3D-QSAR study
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As a continuous effort to develop novel antitumor agents, a new series of forty-five 2-phenol-4-aryl-6-chlorophenyl pyridine compounds were synthesized and evaluated for cytotoxicity against four different human cancer cell lines (DU145, HCT15, T47D, and HeLa), and topoisomerase I and II inhibitory activity. Several compounds (10-15, 20, 22, 24, 28, 42, and 49) displayed strong to moderate dual topoisomerase I and II inhibitory activity at 100 μM. It was observed that hydroxyl and chlorine moiety at meta or para position of phenyl ring is favorable for dual topoisomerase inhibitory activity and cytotoxicity. Most of the compounds displayed stronger cytotoxicities than those of all positive controls against the HCT15 and T47D cell lines. For investigation of the structure-activity relationships, a 3D-QSAR analysis using the method of comparative molecular field analysis (CoMFA) was performed. The generated 3D contour maps can be used for further rational design of novel terpyridine derivatives as highly selective and potent cytotoxic agents.
- Karki, Radha,Jun, Kyu-Yeon,Kadayat, Tara Man,Shin, Somin,Thapa Magar, Til Bahadur,Bist, Ganesh,Shrestha, Aarajana,Na, Younghwa,Kwon, Youngjoo,Lee, Eung-Seok
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p. 228 - 245
(2016/03/08)
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- Evaluation of DPPH radical scavenging activity of 2-(furan-2′-yl)-3-hydroxy-4H-chromen-4-one and their derivatives
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The 2-(furan-2′-yl)-3-hydroxy-4H-chromen-4-one and their substituted derivatives with electron donating and electron withdrawing groups have been synthesized. Free radical scavenging activity has been studied using 2,2′-diphenyl-1-picrylhydrazine (DPPH).
- Kaur, Ranbir,Kaur, Kulvir,Bansal, Manisha
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p. 1921 - 1924
(2016/07/06)
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- Topoisomerase I and II inhibitory activity, cytotoxicity, and structure-activity relationship study of dihydroxylated 2,6-diphenyl-4-aryl pyridines
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Abstract A new series of thirty-six dihydroxylated 2,6-diphenyl-4-aryl pyridines containing hydroxyl groups at the ortho, meta, or para position of 2- and 6-phenyl rings attached to the central pyridine were designed and synthesized. They were evaluated f
- Karki, Radha,Song, Chanju,Kadayat, Tara Man,Magar, Til Bahadur Thapa,Bist, Ganesh,Shrestha, Aarajana,Na, Younghwa,Kwon, Youngjoo,Lee, Eung-Seok
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p. 3638 - 3654
(2015/08/03)
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- Electromeric effect of substitution at 6 th position in 2-(Furan-2-yl)-3-hydroxy-4 H-chromen-4-one (FHC) on the absorption and emission spectra
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Five 3-Hydroxychromones (3HCs), namely, 2-(furan-2-yl)-3-hydroxy-4H-chromen-4-one (FHC) and its four derivatives by substitution of -CH3, -OH, -NO2 and -Cl at 6th position were synthesized from their corresponding 2′-hydro
- Bansal, Manisha,Kaur, Ranbir
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p. 405 - 412
(2015/05/13)
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- NHC-catalyzed reaction of enals with hydroxy chalcones: Diastereoselective synthesis of functionalized coumarins
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The N-heterocyclic carbene-catalyzed annulation of enals with 2′-hydroxy chalcones afford cyclopentane-fused coumarin derivatives with an excellent level of diastereocontrol. The reaction tolerates a broad range of functional groups; 25 examples are given, and a preliminary mechanistic investigation is provided.
- Bhunia, Anup,Patra, Atanu,Puranik, Vedavati G.,Biju, Akkattu T.
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supporting information
p. 1756 - 1759
(2013/06/27)
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- Synthesis and cdc25B inhibitory activity evaluation of chalcones
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A library of sixty-five chalcones was prepared for screening against the protein phosphatase, cdc25B. From this library, thirteen compounds were found having good inhibitory activity. Two compounds have excellent activity and can be used for the design of
- Zhao, Fei,Zhao, Qing-Jie,Zhao, Jing-Xia,Zhang, Da-Zhi,Wu, Qiu-Ye,Jin, Yong-Sheng
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p. 206 - 214
(2013/07/26)
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- Asymmetric ion-pairing catalysis of the reversible cyclization of 2'-hydroxychalcone to flavanone: Asymmetric catalysis of an equilibrating reaction
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The asymmetric catalytic cyclization of the simple 2'-hydroxychalcone (1) to flavanone (2), a model for the chalcone isomerase reaction, has been realized as a catalytic asymmetric ion-pairing process with chiral quaternary ammonium salts (e.g., 9-anthracenylmethlycinchoninium chloride; 9-Am-CN-Cl) and NaH as small-molecule co-catalyst. In toluene/CHCl3 solution, the process reaches an intrinsic enantioselectivity of up to S = 14.4 (er = 93.5:6.5). The reversible reaction proceeds in two steps: A fast initial reaction approaches a quasi-equilibrium with KR/S = 4.5, followed by a second, slow racemization phase approaching Krac = 9. A simple mechanistic model featuring a living ion-pairing catalysis with full reversibility is proposed. Deuterium transfer from co-solvent CDCl3 to product 2 and isolation of a Michael conjugate formed from 2 and 1 demonstrate the intermediacy of flavanone enolate ion pairs. A kinetic model shows good agreement with the experimentally observed, peculiar, time-dependent evolution of the species concentrations and the enantiomeric excess of 2. The reaction is a chemical model of the chalcone isomerase enzymatic reaction. Furthermore, it is an ideal model for studying the characteristic behavior of reversible asymmetric catalyses close to their equilibria.
- Hintermann, Lukas,Dittmer, Claudia
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supporting information
p. 5573 - 5584
(2012/11/13)
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- An unexpected rearrangement-hydration reaction sequence of 2H-chromenes to dihydrochalcones under catalysis of HAuCl4
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2-Aryl-2H-chromenes in aqueous DCM medium under catalysis of HAuCl 4 are converted into 3-(2-hydroxyaryl)-1-arylpropan-1-ones through hydration-rearrangement reaction sequence in very good yield. The key step probably involves the [1,5] hydride shift followed by the hydrolysis under the reaction condition. The notable advantages of this method are operational simplicity and ease of isolation of products and also provide a pathway to convert the chalcone into DHCs with the transposition of carbonyl group. 2012 Elsevier Ltd. All rights reserved.
- Maiti, Gourhari,Kayal, Utpal,Karmakar, Rajiv,Bhattacharya, Rudraksha N.
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p. 6321 - 6325,5
(2012/12/12)
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- Synthesis and anti-bacterial activity of some heterocyclic chalcone derivatives bearing thiofuran, furan, and quinoline moieties
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36 Novel heterocyclic chalcone derivatives were synthesized and tested for their anti-bacterial activity. Some compounds presented good anti-microbial activities against Gram-positive bacteria (including the multidrug-resistant clinical isolates). This cl
- Zheng, Chang-Ji,Jiang, Sheng-Ming,Chen, Zhen-Hua,Ye, Bai-Jun,Piao, Hu-Ri
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experimental part
p. 689 - 695
(2012/06/01)
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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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- Ionic liquid mediated Cu-catalyzed cascade oxa-Michael-oxidation: Efficient synthesis of flavones under mild reaction conditions
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Flavonoids are a class of natural products, found in a wide range of vascular plants and dietary components. Their low toxicity and extensive biological activities, including anti-cancer and anti-bacterial, have made them attractive candidates to serve as therapeutic agents for many diseases. Herein, we disclose a highly efficient synthetic method of CuI-catalyzed cascade oxa-Michael-oxidation, using chalcones as substrates, mediated by the ionic liquid [bmim][NTf2] at a low temperature. This efficient synthetic method has demonstrated high synthetic utility and can afford flavones in good to high yields (up to 98%).
- Du, Zhiyun,Ng, Huifen,Zhang, Kun,Zeng, Huaqiang,Wang, Jian
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supporting information; experimental part
p. 6930 - 6933
(2011/11/04)
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- Design, synthesis, and bioactivities screening of a diaryl ketone-inspired pesticide molecular library as derived from natural products
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Three natural products, 1,5-diphenylpentan-1-one, 1,5-diphenylpent-2-en-1-one, and 3-hydroxy-1,5-diphenylpentan-1-one, with good insecticidal activities were extracted from Stellera chamaejasme L. Based on their shared diaryl ketone moiety as 'pharmacophores', a series of diaryl ketones were synthesized and tested for insecticidal activity, acetylcholinesterase inhibitory activity, and antifungal activity. All synthesized compounds showed poor insecticidal and acetylcholinesterase inhibitory activities. Compound III with a furyl ring showed strong activities against plant pathogenic fungi. The IC50 of compound (E)-1-(2,4-dichlorophenyl)-3-(furan-2-yl)- -prop-2-en-1-one (III2) was 1.20mg/L against Rhizoctonia solani, suggesting its strong potential as a novel antifungal drug.
- Zhang, Hong,Jin, Hong,Ji, Lan-Zhu,Tao, Ke,Liu, Wei,Zhao, Hao-Yu,Hou, Tai-Ping
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experimental part
p. 94 - 100
(2012/06/01)
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- Screening of biological activities of a series of chalcone derivatives against human pathogenic microorganisms
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In an effort to develop new antimicrobial agents, a series of chalcone derivatives, 3-60, were prepared by Claisen-Schmidt condensation of appropriate acetophenones and 2-furyl methyl ketones with appropriate aromatic aldehydes, furfural, and thiophene-2-carbaldehyde in an aqueous solution of NaOH and EtOH at room temperature. The synthesized compounds were characterized by means of their IR- and NMR-spectral data, and elemental analysis. All compounds were tested for their antibacterial and antifungal activities by the disc diffusion method. For the most active compounds, also minimum inhibitory concentrations (MICs) were determined.
- Karaman, Isa,Gezegen, Hayreddin,Guerdere, M. Burcu,Dingil, Alparslan,Ceylan, Mustafa
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experimental part
p. 400 - 408
(2010/09/04)
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- Potassium-tertiary butoxide-assisted addition of thioglicolic acid to chalcone derivatives under solvent-free conditions
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A series of chalcone derivatives containing thioglicolic acid (4a-j) was prepared by addition of thioglicolic acid to the chalcones (3a-j) in the presence of KOt-Bu under solvent-free conditions. The mechanistic pathway of the reaction can be explained by
- Ceylan, Mustafa,Guerdere, Meliha Burcu,Gezegen, Hayreddin,Budak, Yakup
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experimental part
p. 2598 - 2606
(2010/10/03)
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- Small molecules with structural similarities to siderophores as novel antimicrobials against Mycobacterium tuberculosis and Yersinia pestis
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Drugs inhibiting the iron scarcity-induced, siderophore-mediated iron-scavenging systems of Mycobacterium tuberculosis (Mtb) and Yersinia pestis (Yp) may provide new therapeutic lines of defense. Compounds with structural similarities to siderophores were synthesized and evaluated as antimicrobials against Mtb and Yp under iron-limiting conditions, which mimic the iron scarcity these pathogens encounter and must adapt to in the host, and under standard iron-rich conditions for comparison. New antimicrobials were identified, some of which warrant exploration as initial leads against potentially novel targets and small-molecule tools to assist in the elucidation of targets specific to iron-scarcity adapted Mtb and Yp.
- Stirrett, Karen L.,Ferreras, Julian A.,Jayaprakash, Venkatesan,Sinha, Barij N.,Ren, Tao,Quadri, Luis E.N.
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p. 2662 - 2668
(2008/12/21)
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- Enantioselective synthesis of chromanes by iridium-catalyzed asymmetric hydrogenation of 4H-chromenes
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Iridium complexes of chiral oxazoline-based P,N-ligands proved to be efficient catalysts for the enantioselective hydrogenation of 2-aryl- and 2-alkyl-4H-chromenes. The best results were obtained with a ligand derived from threonine (ThrePHOX), which induced ee values of 95% to >99% in the hydrogenation of 2-methyl-, 2-cyclohexyl- and various 2-aryl-substituted chromenes. Georg Thieme Verlag Stuttgart.
- Valla, Carine,Baeza, Alejandro,Menges, Frederik,Pfaltz, Andreas
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scheme or table
p. 3167 - 3171
(2009/06/17)
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- Pyrazoline-based mycobactin analogues as MAO-inhibitors
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3,5-Diaryl carbothioamide pyrazolines designed as mycobactin analogs (mycobacterial siderophore) were reported to be potent antitubercular agents under iron limiting condition in our earlier study. Clinical complications of newly introduced antibiotic Linezolid, due its MAO inhibitory activity, prompted us to evaluate our compounds for their MAO-inhibitory activity against rat liver MAO-A and MAO-B as pyrazolines were reported to be antidepressants and MAO inhibitors. The present study carried out with this pilot library of 32 compounds will provide us with necessary information for designing antitubercular molecules with reduced MAO-inhibitory activity and also help us in identifying a selective MAO-B inhibitor which has potential clinical utility in neurodegenerative disorders. Thirty-two compounds analyzed has shown spectrum of activity from selective to nonselective against two isoforms of rat liver MAO-A and MAO-B and also as competitive, reversible to non-competitive, irreversible. It is also interesting to note that anti-tubercular compound 11, 14 and 16 were also found to be selective inhibitors of rat liver MAO-B. Docking studies with human MAO shows that compound 11 interacts with the catalytic site of both the isoforms, suggesting compound 11 as nonselective inhibitor of human MAO isoforms.
- Jayaprakash, Venkatesan,Sinha, Barij N.,Ucar, Gulberk,Ercan, Ayse
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scheme or table
p. 6362 - 6368
(2009/09/30)
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- Synthesis of chiral 3-substituted indanones via an enantioselective reductive-heck reaction
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(Chemical Equation Presented) An efficient intramolecular palladium-catalyzed, asymmetric reductive-Heck reaction has been developed, which allowed for the synthesis of either enantiomerically enriched 3-substituted indanones or α-exo-methylene indanones depending on the base used.
- Minatti, Ana,Zheng, Xiaolai,Buchwald, Stephen L.
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p. 9253 - 9258
(2008/03/13)
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- Synthetic chalcones, flavanones, and flavones as antitumoral agents: Biological evaluation and structure-activity relationships
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A series of synthetic chalcones, flavanones, and flavones has been synthesized and evaluated for antitumor activity against the human kidney carcinoma cells TK-10, human mammary adenocarcinoma cells MCF-7 (estrogen receptor-positive), and human colon adenocarcinoma cells HT-29. The most active series is the chalcone ones with the best results against TK-10 and HT-29 cells. Fourteen out of 53 analyzed compounds resulted very active against at least two of the studied tumoral cells. Alkaline single cell gel electrophoresis, comet assay, was performed as a study of the chromosomal aberrations promoted by the compounds on normal cells. Four active and two inactive chalcones were studied in the comet assay against normal human kidney cells (HK-2). A structure-activity relationship analysis of these compounds was performed and for 4- and 3,4-disubstituted derivatives a quantitative correlation was obtained in the case of anti-HT-29 activity.
- Cabrera, Mauricio,Simoens, Macarena,Falchi, Gabriela,Lavaggi, M. Laura,Piro, Oscar E.,Castellano, Eduardo E.,Vidal, Anabel,Azqueta, Amaia,Monge, Antonio,de Cerain, Adela Lopez,Sagrera, Gabriel,Seoane, Gustavo,Cerecetto, Hugo,Gonzalez, Mercedes
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p. 3356 - 3367
(2008/02/07)
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- A facile one pot microwave- assisted solid phase synthesis of 2-amino-4,6-diaryl pyrimidines and their antibacterial activity
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An environmentally benign, manipulatively simple & rapid method for the synthesis of 2-amino-4, 6-diaryl pyrimidines (4a-f) from corresponding chalcones (3a-f) & guanidine nitrate using basic alumina under solvent free dry condition and microwave irradiat
- Jhala, Yajuvendra S.,Gahlot,Dulawat, Shiv S.,Verma
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p. 253 - 258
(2007/10/03)
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- New synthesis of flavanones catalyzed by L-proline
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L-Proline is utilized as an efficient organocatalyst for the synthesis of substituted flavanones and chalcones in good yields. The efficiency of the catalyst was proved with a variety of substrates ranging from electron-deficient to electron-rich aryl aldehydes and 2-hydroxyacetophenones.
- Chandrasekhar,Vijeender,Venkatram Reddy
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p. 6991 - 6993
(2007/10/03)
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- Synthetic chalcones as potential anti-inflammatory and cancer chemopreventive agents
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In an effort to develop potent anti-inflammatory and cancer chemopreventive agents, a series of chalcones were prepared by Claisen-Schmidt condensation of appropriate acetophenones with suitable aromatic aldehyde or prepared with appropriate dihydrochalco
- Won, Shen-Jeu,Liu, Cheng-Tsung,Tsao, Lo-Ti,Weng, Jing-Ru,Ko, Horng-Huey,Wang, Jih-Pyang,Lin, Chun-Nan
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p. 103 - 112
(2007/10/03)
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- Development of novel pesticides based on phytoalexins: Part 2. Quantitative structure-activity relationships of 2-heteroaryl-4-chromanone derivatives
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Phytoalexins are low-molecular-weight chemicals that immune systems of plants produce and accumulate in response to infections, especially those of fungal origin. Although their content is not high in plants, yet they have shown unique fungicidal activity
- Yang, Guangfu,Jiang, Xiaohua,Yang, Huazheng
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p. 1063 - 1067
(2007/10/03)
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