- Flavone-based hydrazones as new tyrosinase inhibitors: Synthetic imines with emerging biological potential, SAR, molecular docking and drug-likeness studies
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Targeting tyrosinase (TYR), a key enzyme responsible for melanogenesis disorders, is a well-known approach utilized for the development of melanogenesis inhibitor. A variety of dermatological disorders and microbial skin infections can cause hyperpigmentation. Hence, exploring new scaffolds for the treatment of melanogenesis disease is an inspiring goal. In this context, a series of varyingly substituted flavone-based hydrazones have been designed, synthesized and characterized successfully. The present study describes the discovery of novel mushroom tyrosinase inhibitors (TIs) for treating hyperpigmentation. In due course, flavone scaffold has been incorporated into the novel chemotypes that exhibit in vitro inhibitory effects against mushroom tyrosinase for the purpose of discovering anti‐melanogenic agents. Biological investigations of prepared analogs herein demonstrated moderate to excellent activity against most of the fungal-bacterial strains and their activity is comparable to those of commercially available antibiotics i.e., Ciprofloxacin and Ketoconazole. Based on in vitro tyrosinase inhibitory assay, some compounds exhibited potent inhibition particularly, 3g (IC50 = 1.40 ± 0.16 μM), 3j (IC50 = 0.95 ± 0.07 μM), 3o (IC50 = 1.13 ± 0.11 μM), and 3q (IC50 = 1.01 ± 0.1 μM) showed best inhibition i.e., 0.7, 0.5, 0.6 and 0.5 folds, respectively, than kojic acid (IC50 = 1.79 ± 0.6 μM). Lineweaver-Burk plots demonstrated that the most potential derivative 3j tyrosinase inhibition proceeds via non-competitive pathway and the Michaelis-Menton constant (Km) value is 0.0265. Molecular modeling was performed for all tested analogs (3a–3q) using a model of mushroom tyrosinase to find crucial binding modes liable for inhibitory activity. The SARs were preliminarily examined, and the docking study revealed that analogs 3j, 3o and 3p had a strong binding association to tyrosinase (2Y9X). Furthermore, a drug-likeness study was employed and confirmed the favorable activity of the new analogs as a new anti-tyrosinase agent.
- Alsantali, Reem?I.,Mughal, Ehsan?Ullah,Naeem, Nafeesa,Alsharif, Meshari?A.,Sadiq, Amina,Ali, Anser,Jassas, Rabab.?S.,Javed, Qamar,Javid, Asif,Sumrra, Sajjad Hussain,Alsimaree, Abdulrahman?A.,Zafar, Muhammad?Naveed,Asghar, Basim?H.,Altass, Hatem?M.,Moussa, Ziad,Ahmed, Saleh?A.
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- Structural and spectroscopic analysis and evaluation of cytotoxic activity of 2-hydroxychalcones against human cancer cell lines
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Chalcones and their derivatives exhibit a broad spectrum of pharmacological activities, including antiproliferative activities. Accordingly, they are deemed robust anticancer candidates for cytotoxicity assays. Herein, we synthesized and characterized fou
- Almeida-Neto, Francisco W. Q.,Bandeira, Paulo N.,Barreto, Ant?nio C. H.,Barros-Nepomuceno, Francisco W. A.,Juli?o, Murilo S. S.,Leal, Antonio L. A. B.,Marinho, Emmanuel S.,Pessoa, Claudia,Pinheiro, Daniel P.,Teixeira, Alexandre M. R.,da Silva, Priscila T.,de Lima-Neto, Pedro,de Paiva, Aldeneide S.,dos Santos, Hélcio S.
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- B regioselective and chemoselective biotransformation of 2′-hydroxychalcone derivatives by marine-derived fungi
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Eight fungal strains (Penicillium raistrickii CBMAI 931, Cladosporium sp. CBMAI 1237, Aspergillus sydowii CBMAI 935, Penicillium oxalicum CBMAI 1996, Penicillium citrinum CBMAI 1186, Mucor racemosus CBMAI 847, Westerdykella sp. CBMAI 1679, and Aspergillus sclerotiorum CBMAI 849) mediated the biotransformation of the 2′-hydroxychalcone 1a. The main products obtained were from hydrogenation, hydroxylation, and cyclization reactions. Penicillium raistrickii CBMAI 931 catalyzed the chemoselective reduction of 1a to produce 2′-hydroxydihydrochalcone 2a (72%) in 7 days of incubation in phosphate buffer (pH 7). Aspergillus sydowii CBMAI 935 promoted the hydroxylation of 1a to yield 2′,4-dihydroxy-dihydrochalcone 5a (c = 42%) in 7 days of incubation in phosphate buffer (pH 8). The reaction using P. citrinum CBMAI 1186 and M. racemosus CBMAI 847 presented main cyclization products in phosphate buffer (pH 8), but the reactions with these fungi did not present enantioselectivity. Marine-derived fungi were effective and versatile biocatalysts for biotransformation of the 2′-hydroxychalcones yielding different products according to the conditions and microorganism used.
- Nitschke, Marcia,Porto, André Luiz Meleiro,de Matos, Iara Lisboa
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- Stereoselective reduction of flavanones by marine-derived fungi
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Biotransformation is an alternative with great potential to modify the structures of natural and synthetic flavonoids. Therefore, the bioreduction of synthetic halogenated flavanones employing marine-derived fungi was described, aiming the synthesis of flavan-4-ols 3a-g with high enantiomeric excesses (ee) of both cis- and trans-diastereoisomers (up to >99% ee). Ten strains were screened for reduction of flavanone 2a in liquid medium and in phosphate buffer solution. The most selective strains Cladosporium sp. CBMAI 1237 and Acremonium sp. CBMAI1676 were employed for reduction of flavanones 2a-g. The fungus Cladosporium sp. CBMAI 1237 presented yields of 72–87% with 0–64% ee cis and 0–30% ee trans with diastereoisomeric ratio (dr) from 52:48 to 64:36 (cis:trans). Whereas Acremonium sp. CBMAI 1676 resulted in 31% yield with 77–99% ee of the cis and 95–99% ee of the trans-diastereoisomers 3a-g with a dr from 54:46 to 96:4 (cis:trans). To our knowledge, this is the first report of the brominated flavon-4-ols 3e and 3f. The use of fungi, with emphasis for these marine-derived strains, is an interesting approach for enantioselective reduction of halogenated flavanones. Therefore, this strategy can be explored to obtain enantioenriched compounds with biological activities.
- Birolli, Willian G.,Nitschke, Marcia,Porto, André Luiz M.,Santos, Darlisson de A.,de Matos, Iara L.
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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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- Experimental and theoretical insights into the photophysical and electrochemical properties of flavone-based hydrazones
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A small library of flavone-based hydrazones has been designed, synthesized and characterized. In this context, thirteen flavone hydrazones (3a-3 m) were synthesized by the acid-catalyzed condensation of flavone with 2,4-dinitrophenylhydrazine (2,4-DNPH) and characterized by different spectral techniques (IR, UV–Vis, NMR and mass spectrometry). The electrochemical, photophysical and theoretical investigations of such type of compounds are hitherto unknown. The electrochemical behavior of these hydrazones at a platinum electrode has been analyzed by cyclic voltammetry (CV) and was investigated at 200, 100 and 40 mVs?1 in acetonitrile (CH3CN). These hydrazones showed a quasi-reversible redox reaction. The oxidation–reduction reactive sites of these derivatives were located via geometry optimization using density functional theory (DFT) at the B3LYP/3–21 g in the Guassian-09 level of theory. Moreover, the target compounds exhibited interesting fluorescent properties. Owing to their excellent photophysical and redox results, a detailed structure-property relationship was established to assess the substituents impact and their position on the physicochemical and electronic properties. All the experimental results were in accordance with the computational studies.
- Ahmed, Ishtiaq,Ahmed, Safeer,Ahmed, Saleh A.,Alsantali, Reem I.,Alsharif, Meshari A.,Altaf, Ataf Ali,Altass, Hatem M.,Jassas, Rabab. S.,Kausar, Samia,Mughal, Ehsan Ullah,Mumtaz, Amara,Naeem, Nafeesa,Obaid, Rami J.,Sadiq, Amina,Zafar, Muhammad Naveed
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- Substituent-Controlled Divergent Cascade Cycloaddition Reactions of Chalcones and Arylalkynols: Access to Spiroketals and Oxa-Bridged Fused Heterocycles
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Herein, we report substituent-controlled divergent cascade cycloaddition reactions of chalcones and arylalkynols in the presence of PtI2. Depending on the substituent on the chalcone, either spiroketals or oxa-bridged fused heterocycles could be obtained in the ranges of 86–97% and 87–95% yields under identical reaction conditions. Control experiments were carried out to elucidate the origin of the high chemoselectivity. These provide a method for the synthesis of a diverse array of structurally complex oxygen-containing heterocycles. (Figure presented.).
- Chang, Weixing,Kong, Jingyang,Li, Jing,Liu, Lingyan,Wang, Hongkai,Zeng, Tianlong
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supporting information
p. 4024 - 4032
(2021/07/12)
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- Mycobactin Analogues with Excellent Pharmacokinetic Profile Demonstrate Potent Antitubercular Specific Activity and Exceptional Efflux Pump Inhibition
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In this study, we have designed and synthesized pyrazoline analogues that partially mimic the structure of mycobactin, to address the requirement of novel therapeutics to tackle the emerging global challenge of antimicrobial resistance (AMR). Our investigation resulted in the identification of novel lead compounds 44 and 49 as potential mycobactin biosynthesis inhibitors against mycobacteria. Moreover, candidates efficiently eradicated intracellularly surviving mycobacteria. Thermofluorimetric analysis and molecular dynamics simulations suggested that compounds 44 and 49 bind to salicyl-AMP ligase (MbtA), a key enzyme in the mycobactin biosynthetic pathway. To the best of our knowledge, these are the first rationally designed mycobactin inhibitors to demonstrate an excellent in vivo pharmacokinetic profile. In addition, these compounds also exhibited more potent whole-cell efflux pump inhibition than known efflux pump inhibitors verapamil and chlorpromazine. Results from this study pave the way for the development of 3-(2-hydroxyphenyl)-5-(aryl)-pyrazolines as a new weapon against superbug-associated AMR challenges.
- Basavanakatti, Vinay N.,Bhakta, Sanjib,Bhattacharje, Gourab,Brucoli, Federico,Das, Amit Kumar,Das, Swetarka,Dasgupta, Arunava,Dev, Abhimanyu,Dickman, Rachael,Jalani, Pushpendu,Jayaprakash, Venkatesan,Kamilya, Sujit,Mondal, Abhishake,Mukherjee, Piyali,Naresh Babu, Patibandla,Sankaran, Vadivelan,Shyam, Mousumi,Singh, Amit,Singh, Samsher,Sinha, Barij Nayan,Verma, Harshita,Bagnéris, Claire
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- Differences in antioxidant potential of chalcones in human serum: In vitro study
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Introduction: An imbalance between oxidants and antioxidants in favour of oxidants, potentially leading to damage, is termed oxidative stress. Antioxidants (AO), either enzymatic or non-enzymatic, are the ones that can reduce diverse effects of pro-oxidan
- Ivkovi?, Branka,Jankovi?, Tamara,Kotur-Stevuljevi?, Jelena,Turkovi?, Nemanja,Vuji?, Zorica
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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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- Effect of substituents in the A and B rings of chalcones on antiparasite activity
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Chalcones are a group of natural products with many recognized biological activities, including antiparasitic activity. Although a lot of chalcones have been synthetized and assayed against parasites, the number of structural features known to be involved in this biological property is small. Thus, in the present study, 21 chalcones were synthesized to determine the effect of substituents in the A and B rings on the activity against Leishmania braziliensis, Trypanosoma cruzi, and Plasmodium falciparum. The compounds were active against L. braziliensis in a structure-dependent manner. Only one compound was very active against T. cruzi, but none of them had a significant antiplasmodial activity. The electron-donating substituents in ring B and the hydrogen bonds at C-2′ with carbonyl affect the antiparasitic activity.
- González, Luis A.,Upegui, Yulieth A.,Rivas, Luis,Echeverri, Fernando,Escobar, Gustavo,Robledo, Sara M.,Qui?ones, Wiston
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- Synthesis and characterization of some new pyrazolines and their inhibitory potencies against carbonic anhydrases
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The inhibition of the two human cytosolic carbonic anhydrase (hCA; EC 4.2.1.1) isozymes I and II with some new pyrazoline derivatives was investigated for the first time. The structures of the newly synthesized pyrazoline derivatives were characterized by
- ?elik, Gonca,?entürk, Murat,Arslan, Tayfun,Ekinci, Deniz
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- Chiral Hydroxytetraphenylene-Boron Complex Catalyzed Asymmetric Diels-Alder Cycloaddition of 2′-Hydroxychalcones
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(S)-2,15-Cl2-DHTP-boron complex catalyst for the asymmetric Diels-Alder cycloaddition of 2′-hydroxychalcones and dienes was developed and tested. The resulting cyclohexenes with three chiral centers were obtained in high yields (up to 98%) with excellent stereoselectivities (up to >20:1 endo/exo, >99% ee). This catalytic system features high efficiency, broad substrate scopes, and mild reaction conditions. In addition, a DFT study was performed to explain the stereochemical course of the asymmetric induction.
- Chai, Guo-Li,Qiao, Yan,Zhang, Ping,Guo, Rong,Wang, Juan,Chang, Junbiao
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supporting information
p. 8023 - 8027
(2020/11/02)
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- Enzyme-assisted cyclization of chalcones to flavanones
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Enzyme catalyzed synthesis is an eco-friendly technique in organic synthesis, having several benefits over conventional methods. In the present work, we describe a simple process of laccase and chloroperoxidase assisted cyclization of chalcones, leading to the formation of flavanones. The reaction proceeds in a mixture of phosphate buffer and ethanol, under oxygen atmosphere at room temperature, yielding the corresponding flavanone in good to moderate yield. The relative configuration of the products at C2 is tentatively assigned as S*-flavanone based on the coupling constants with the methylenic protons H3α,β. In comparison to the chemical methods, we describe a process which can be achieved efficiently under mild conditions using oxygen as oxidant.
- Alonso, Mariana Macías,Boluda, Carlos José,Barajas, Gabriela Díaz,Sánchez, Nallely Caldera,Córdova-Guerrero, Iván,Marrero, Joaquín González
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p. 926 - 931
(2020/12/23)
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- Novel chalcone derivatives containing a 1,2,4-triazine moiety: Design, synthesis, antibacterial and antiviral activities
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A series of novel chalcone derivatives containing the 1,2,4-triazine moiety were synthesized and their structures were confirmed by 1H NMR, 13C NMR and elemental analyses. Antiviral bioassays revealed that most of the compounds exhibited good antiviral activity against tobacco mosaic virus (TMV) at a concentration of 500 μg mL-1. The designated compound 4l was 50% effective in terms of curative and protective activities against TMV with 50% effective concentrations (EC50) of 10.9 and 79.4 μg mL-1, which were better than those of ningnanmycin (81.4 and 82.2 μg mL-1). Microscale thermophoresis (MST) also showed that the binding of compound 4l to coat protein (TMV-CP) yielded a Kd value of 0.275 ± 0.160 μmol L-1, which was better than that of ningnanmycin (0.523 ± 0.250 μmol L-1). At the same time, molecular docking studies for 4l with TMV-CP (PDB code:1EI7) showed that the compound was embedded well in the pocket between the two subunits of TMV-CP. Meanwhile, compound 4a demonstrated excellent antibacterial activities against Ralstonia solanacearum (R. solanacearum), with an EC50 value of 0.1 μg mL-1, which was better than that of thiodiazole-copper (36.1 μg mL-1) and bismerthiazol (49.5 μg mL-1). The compounds act by causing folding and deformation of the bacterial cell membrane as observed using scanning electron microscopy (SEM). The chalcone derivatives thus synthesized could become potential alternative templates for novel antiviral and antibacterial agents.
- Tang, Xu,Su, Shijun,Chen, Mei,He, Jun,Xia, Rongjiao,Guo, Tao,Chen, Ying,Zhang, Cheng,Wang, Jun,Xue, Wei
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p. 6011 - 6020
(2019/03/12)
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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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- Temperature-Controlled Stereodivergent Synthesis of 2,2′-Biflavanones Promoted by Samarium Diiodide
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In this work, the first example of a radical stereodivergent reaction directed towards the stereoselective synthesis of both (R*,R*)- and (R*,S*)-2,2′-biflavanones promoted by samarium diiodide is reported. Control experiments showed that the selectivity of this reaction was exclusively controlled by the temperature. It was possible to generate a variety of 2,2′-biflavanones bearing different substitution patterns at the aromatic ring in good-to-quantitative yields, being both stereoisomers of the desired compounds obtained with total or high control of selectivity. A mechanism that explains both the generation of the corresponding 2,2′-biflavanones and the selectivity is also discussed. The structure and stereochemistry determination of each isomer was unequivocally elucidated by single-crystal X-ray diffraction experiments.
- Soto, Martín,Soengas, Raquel G.,Silva, Artur M. S.,Gotor-Fernández, Vicente,Rodríguez-Solla, Humberto
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supporting information
p. 13104 - 13108
(2019/10/21)
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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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- 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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- Ultrasound-assisted synthesis and antimicrobial activity of tetrazole-based pyrazole and pyrimidine derivatives
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New tetrazole-based pyrazole and pyrimidine derivatives were synthesized by an ultrasound irradiation method. All compounds were characterized by infrared spectroscopy (IR), 1H nuclear magnetic resonance (NMR), 13C NMR, mass spectrometry (MS) and elemental analysis and assessed in vitro for their efficacy as antimicrobial agents against four bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa) and two fungi (Candida albicans, Aspergillus Niger). Compounds 8a, 8e, 9a, 9b and 9e show potent activity against the tested strains compared to the reference drugs chloramphenicol and clotrimazole.
- Dofe, Vidya S.,Sarkate, Aniket P.,Shaikh, Zarina M.,Gill, Charansingh H.
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- Halo-substituted chalcones and azachalcones-inhibited, lipopolysaccharited-stimulated, pro-inflammatory responses through the TLR4-mediated pathway
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A series of B-ring, halo-substituted chalcones and azachalcones were synthesized to evaluate and compare their anti-inflammatory activity. Mouse BALB/c macrophage RAW 264.7 were pre-treated with 10 μg/mL of each compound for one hour before induction of i
- Shih, Tzenge-Lien,Liu, Ming-Hwa,Li, Chia-Wai,Kuo, Chia-Feng
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- Synthesis, Characterization, and Crystal Structure of (2E)-3-(4-Fluorophenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one
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The title chalcone, of formula C15H11F1O2, crystallized in the orthorhombic space group P212121 (# 19) with crystal parameters a = 6.9998(8) ?, b = 12.6740(15) ?, c = 12.8997(15)
- Slabber, Cathryn A.,Grimmer, Craig D.,Munro, Orde Q.,Robinson, Ross S.
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p. 213 - 219
(2018/09/25)
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- Design, synthesis and biological evaluation of novel dihydropyrimidine-2-thione derivatives as potent antimicrobial agents: Experimental and molecular docking approach
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Introduction: Dihydropyrimidine scaffold represent an important class of pharmacologically active nitrogen containing heterocyclic compounds. A wide range of molecules with dihydropyrimidine moieties have important role in medicinal chemistry on account of their potential biological activities. Methodology: A series of 3,4-dihydropyrimidine-2(1H)-thione derivatives have been designed and synthesized in a concise way through condensation of variously substituted chalcones with thiourea in alkaline alcoholic solutions. In order to investigate their biological significance, these compounds were tested for their in vitro antimicrobial potential against various bacterial and fungal strains. Moreover, the experimental results were supported by molecular docking studies. Results and Discussion: The newly synthesized compounds were characterized by the usual spectroscopic techniques In case of antibacterial activity, the compounds 5 (40.3±0.44 mm), 12 and 13 (almost 35 mm) exhibited highest zone of inhibitions against Methicillin-resistant Staphylococcus auerus (MRSA) bacterial strain as compared to the standard drug Cefixime. These compounds displayed moderate to good activities against all attempted fungal strains. In docking analysis, it has been observed that compounds 8 (-6.4017 Kcal/mol) and 10 (-6.1319 Kcal/mol) revealed significant binding affinity against penicillin binding protein (PDB ID: 1VQQ), while compounds 1 (-143.23 Kcal/mol) and 2 (-146.99 Kcal/mol) showed best activity for shikimate dehydrogenase (PDB ID: 3DON). Conclusion: In conclusion, we have designed, synthesized and characterized an interesting series of biologically active dihydropyrimidine derivatives. Remarkably, most of the synthesized compounds were found more active against all tested bacterial strains in comparison to the standard drug Cefixime as manifested by experimental as well as theoretical results.
- Mughal, Ehsan Ullah,Sadiq, Amina,Hamayun, Muhammad,Zafar, Muhammad Naveed,Fatima, Nighat,Yameen, Muhammad Arfat,Muhammad, Syed Aun,Mumtaz, Amara,Ahmed, Ishtiaq,Fatima, Tehseen
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p. 1189 - 1201
(2018/11/01)
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- Ruthenium(II)-Catalyzed Synthesis of Spirobenzofuranones by a Decarbonylative Annulation Reaction
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The first decarbonylative insertion of an alkyne through C?H/C?C activation of six-membered compounds is reported. The Ru-catalyzed reaction of 3-hydroxy-2-phenyl-chromones with alkynes works most efficiently in the presence of the ligand PPh3 to provide spiro-indenebenzofuranones. Unlike previously reported metal-catalyzed decarbonylative annulation reactions, in the present decarbonylative annulation reaction, the annulation occurs before extrusion of carbon monoxide.
- Kaishap, Partha P.,Duarah, Gauri,Sarma, Bipul,Chetia, Dipak,Gogoi, Sanjib
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supporting information
p. 456 - 460
(2018/02/21)
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- Synthesis, structure-activity relationship and molecular docking studies of 3-O-flavonol glycosides as cholinesterase inhibitors
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The prime objective of this research work is to prepare readily soluble synthetic analogues of naturally occurring 3-O-flavonol glycosides and then investigate the influence of various substituents on biological properties of synthetic compounds. In this context, a series of varyingly substituted 3-O-flavonol glycosides have been designed, synthesized and characterized efficiently. The structures of synthetic molecules were unambiguously corroborated by IR, 1H, 13C NMR and ESI-MS spectroscopic techniques. The structure of compound 22 was also analyzed by X-ray diffraction analysis. All the synthetic compounds (21–30) were evaluated for in vitro inhibitory potential against cholinesterase enzymes. The results displayed that most of the derivatives were potent inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with varying degree of IC50 values. The experimental results were further encouraged by molecular docking studies in order to explore their binding behavior with the active pocket of AChE and BChE enzymes. The experimental and theoretical results are in parallel with one another.
- Mughal, Ehsan Ullah,Javid, Asif,Sadiq, Amina,Murtaza, Shahzad,Zafar, Muhammad Naveed,Khan, Bilal Ahmad,Sumra, Sajjad Hussain,Tahir, Muhammad Nawaz,Kanwal,Khan, Khalid Mohammed
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p. 3696 - 3706
(2018/06/19)
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- Synthesis, antimicrobial evaluation, and molecular docking studies of novel chromone based 1,2,3-triazoles
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Abstract: In Search of novel antimicrobial agents with improved potency, we designed and synthesized a series of 3-((1-benzyl-1H-1,2,3-triazol-4-yl)methoxy)-2-(4-fluorophenyl)-4H-chromen-4-ones 5a–f using click chemistry. The structures of synthesized com
- Dofe, Vidya S.,Sarkate, Aniket P.,Lokwani, Deepak K.,Kathwate, Santosh H.,Gill, Charansingh H.
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- Synthesis and biological evaluation of α-methyl-chalcone for anti-cervical cancer activity
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A series of 31 chalcones were synthesized and evaluated for anti-proliferative activity against the human cervical cancer cell lines (HeLa and SiHa). Compound 19, (E)-1-(2,4-dihydroxyphenyl)-3-(4-(dimethylamino) phenyl)-2-methylprop-2-en-1-one was found to be an effective anti-proliferative agent in HeLa and SiHa cells (IC50 = 0.035 μM). Compound 19 increased the percentage of apoptosis in a dose-dependent manner, as measured by Annexin V-FITC (fluorescein isothiocyanate)/(propidium iodide) PI staining. Molecular modeling studies of compound 19 showed that the most potent structure was docked at the yeast 20 S proteasome binding site (Protein Data Bank code-3E47) and was stabilized in the cavity by various hydrophobic and hydrogen bonding interactions.
- Ren, Bing-zhao,Ablise, Mourboul,Yang, Xu-chao,Liao, Bo-er,Yang, Zheng
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p. 1871 - 1883
(2017/08/03)
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- Synthesis, antimicrobial activity and anti-biofilm activity of novel tetrazole derivatives
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In the development of antimicrobial agents, we designed and synthesized novel tetrazole derivatives. The structures of compounds 6a-f and 7a-f were characterized by IR, 1H NMR, 13C NMR, MS and elemental analysis. These compounds were tested for their antimicrobial activity against a series of strains Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa and for antifungal activity against the strains Candida albicans, Candida glabrata, and Candida tropicalis. Compounds 6e, 6f, 7a, and 7f exhibit potent antimicrobial activities compared to the reference drugs streptomycin and miconazole. Tetrazole derivatives 7a-f also inhibit biofilm formation and compound 7f exhibits best anti-biofilm activity with a biofilm inhibitory concentration (BIC) as low as 0.9 μm.
- Dofe, Vidya S.,Sarkate, Aniket P.,Kathwate, Santosh H.,Gill, Charansingh H.
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p. 325 - 330
(2017/08/18)
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- Synthesis, molecular docking studies and biological evaluation of 3-iminoaurones as acetylcholinesterase and butyrylcholinesterase inhibitors
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Background: A new series of aurone-hydrazones have been designed and synthesized in order to explore new bioactive compounds, which could have potential to be used as active drugs against Alzheimer’s disease. Methods: The newly synthesized compounds were characterized by various spectroscopic techniques (IR, mass spectrometry and NMR spectroscopy) and evaluated in vitro for their inhibitory potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. All target compounds exhibited varied degree of IC50 values compared to standard Donepezil. Among the series, the compound 6c was found as a potent dual inhibitor of AChE and BChE having IC50 values 0.92±0.01 and 2.25±0.01 μM respectively. Results and Conclusion: The experimental results were further supported by molecular docking analysis. Both studies showed that some of these compounds are interesting inhibitors against AChE and BChE enzymes.
- Mughal, Ehsan Ullah,Sadiq, Amina,Khan, Bilal Ahmad,Zafar, Muhammad Naveed,Ahmed, Ishtiaq,Zubair, Muhammad
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p. 1035 - 1041
(2017/09/12)
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- Synthesis, structure–activity relationship and molecular docking of 3-oxoaurones and 3-thioaurones as acetylcholinesterase and butyrylcholinesterase inhibitors
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The present study describes efficient and facile syntheses of varyingly substituted 3-thioaurones from the corresponding 3-oxoaurones using Lawesson's reagent and phosphorous pentasulfide. In comparison, the latter methodology was proved more convenient, giving higher yields and required short and simple methodology. The structures of synthetic compounds were unambiguously elucidated by IR, MS and NMR spectroscopy. All synthetic compounds were screened for their inhibitory potential against in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Molecular docking studies were also performed in order to examine their binding interactions with AChE and BChE human proteins. Both studies revealed that some of these compounds were found to be good inhibitors against AChE and BChE.
- Mughal, Ehsan Ullah,Sadiq, Amina,Murtaza, Shahzad,Rafique, Hummera,Zafar, Muhammad Naveed,Riaz, Tauqeer,Khan, Bilal Ahmad,Hameed, Abdul,Khan, Khalid Mohammed
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p. 100 - 106
(2016/12/18)
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- Inhibition of LPS-stimulated ROS production by fluorinated and hydroxylated chalcones in RAW 264.7 macrophages with structure-activity relationship study
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Based on the importance of the previous fluorinated and/or hydroxylated chalcones studies, thirty-six compounds were designed as phenyl or hydroxyphenyl bearing fluoro, trifluoromethyl or trifluoromethoxy phenyl propenones and synthesized by applying modified Claisen-Schmidt condensation reaction as a single step. Inhibitory effects of the synthesized compounds on ROS production stimulated by LPS in RAW 264.7 macrophage were evaluated. Structure-activity relationship (SAR) study revealed that the compounds possessing para-hydroxyphenyl group combined with meta-fluoro or meta-trifluoromethyl phenyl group, and meta/para-hydroxyphenyl group combined with ortho-trifluoromethoxyphenyl group have an essential role in inhibiting the LPS-stimulated ROS production in RAW 264.7 macrophages. The most significant inhibitory effect on LPS-stimulated ROS production in RAW 264.7 macrophages was observed in compound 30 that possessed para-hydroxyphenyl group along with ortho-trifluoromethoxyphenyl group.
- Bist, Ganesh,Pun, Nirmala Tilija,Magar, Til Bahadur Thapa,Shrestha, Aarajana,Oh, Hye Jin,Khakurel, Amrita,Park, Pil-Hoon,Lee, Eung-Seok
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supporting information
p. 1205 - 1209
(2017/06/19)
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- Synthesis, anticancer, structural, and computational docking studies of 3-benzylchroman-4-one derivatives
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A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell
- Simon, Lalitha,Abdul Salam, Abdul Ajees,Madan Kumar,Shilpa,Srinivasan,Byrappa
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supporting information
p. 5284 - 5290
(2017/10/30)
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- Ultrasound-Mediated Synthesis of Novel 1,2,3-Triazole-Based Pyrazole and Pyrimidine Derivatives as Antimicrobial Agents
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In the development of novel antimicrobial agents, we synthesized novel 1,2,3-triazole-based pyrazole and pyrimidine derivatives 6(a–f) and 7(a–f) by ultrasound-assisted method. The synthesized compounds were characterized by IR, 1H NMR, 13
- Dofe, Vidya S.,Sarkate, Aniket P.,Shaikh, Zarina M.,Gill, Charansingh H.
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p. 3195 - 3201
(2017/10/06)
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- 3-substituted propyl-2-alkene-1-ketone compound and application thereof
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The invention relates to the technical field of medicine and particularly discloses a 3-substituted propyl-2-alkene-1-ketone compound and application thereof to preparation of antifungal drugs and synergistic antifungal drugs. The compound can be used tog
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Paragraph 0106; 0107; 0108; 0109; 0146; 0147; 0148; 0149
(2016/10/09)
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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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- Modified Pyridine-Substituted Coumarins: A New Class of Antimicrobial and Antitubercular Agents
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Some new biologically potent coumarin derivatives 7a-f, 8a-f, and 9a-f bearing modified pyridine moieties (indeno[1,2-b]pyridine, 4-azaphenanthrene and benzofuro [3,2-b]pyridine) at the sixth position were designed and synthesized. All the synthesized com
- Giri, Rakesh R.,Lad, Hemali B.,Bhila, Varun G.,Patel, Chirag V.,Brahmbhatt
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p. 363 - 375
(2015/10/29)
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- The rearrangement of tosylated flavones to 1′-(alkylamino)aurones with primary amines
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A rearrangement of 3-tosylflavone to the corresponding 1′-(alkylamino)aurone proceeds under mild conditions in the presence of primary amines in high yields. The reaction is applicable to different substituted 3-tosylflavones and alkyl amines and the respective aurones were isolated as a mixture of E/Z isomers. Further conversion of 1′-(methylamino)aurone to the corresponding thionated compound was performed by reaction with Lawesson's reagent and only the E isomer was obtained. This observation can be explained by the weaker exocyclic double bond, which facilitates rotation and the formation of the thermodynamically preferred E form. The characterization, preliminary biological investigations of the synthesized compounds and lipophilicity studies are discussed.
- Kandioller, Wolfgang,Kubanik, Mario,Bytzek, Anna K.,Jakupec, Michael A.,Roller, Alexander,Keppler, Bernhard K.,Hartinger, Christian G.
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p. 8953 - 8959
(2015/11/02)
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- Nanosilica-supported dual acidic ionic liquid as a heterogeneous and reusable catalyst for the synthesis of flavanones under solvent-free conditions
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[Figure not available: see fulltext.] A nanosilica-supported dual acidic ionic liquid on the basis of 1-methyl-3-(4-sulfobutyl)imidazolium hydrogen sulfate was synthesized and used as an efficient, green, non-corrosive, non-toxic, heterogeneous, and reusable catalyst for the synthesis of some new and known substituted flavanones. The synthesis was done by the condensation of 2'-hydroxyacetophenone with different aldehydes and the subsequent cyclization of the resulting 2'-hydroxychalcone in the presence of the catalyst. High yields of the products, short reaction times, and solvent-free conditions characterize this new method.
- Rostamizadeh, Shahnaz,Zekri, Negar,Tahershamsi, Leili
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p. 526 - 530
(2016/02/16)
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- Impact of mono- and disubstitution on the colorimetric dynamic covalent switching chalcone/flavanone scaffold
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The effect of aryl substitution on various aspects of the interconversion of ortho-hydroxychalcones and flavanones has been studied using multiple spectroscopic techniques. Derivatization of the core scaffold predictably alters the midpoint pH of this equilibration process suggesting its viability for application as a functional colorimetric molecular switch.
- Muller, Brian M.,Mai, Jesse,Yocum, Reid A.,Adler, Marc J.
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p. 5108 - 5114
(2014/07/08)
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- Quantum-chemical analysis of the Algar-Flynn-Oyamada reaction mechanism
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This work is devoted to improving the understanding of Algar-Flynn-Oyamada reaction mechanism and the analysis of factors that affect the formation of flavonols. The calculation of thermodynamic parameters for the key reaction steps pointed to a mechanism involving chalcone epoxides as intermediates. A correlation was identified between the nucleophilicity of oxygen atom at position 2' of epoxide anions and the yields of flavonols. An increased charge at the nucleophilic center was shown to reduce the effectiveness of β-cyclization of epoxide anions.
- Serdiuk,Roshal,B?a?ejowski
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p. 396 - 403
(2014/08/05)
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- Superior anticancer activity of halogenated chalcones and flavonols over the natural flavonol quercetin
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A series of chalcone and flavonol derivatives were synthesized in good yield by an eco-friendly approach. A pharmacological evaluation was performed with the human colorectal carcinoma cell line HCT116 and revealed that the anticancer activity of flavonols was higher when compared with that of the respective chalcone precursors. The antiproliferative activity of halogenated derivatives increases as the substituent in the 3- or 4-positon of the B-ring goes from F to Cl and to Br. In addition, halogens in position 3 enhance anticancer activity in chalcones whereas for flavonol derivatives the best performance was registered for the 4-substituted derivatives. Flow cytometry analysis showed that compounds 3p and 4o induced cell cycle arrest and apoptosis as demonstrated by increased S, G2/M and sub-G1 phases. These data were corroborated by western blot and fluorescence microscopy analysis. In summary, halogenated chalcones and flavonols were successfully prepared and presented high anticancer activity as shown by their cell growth and cell cycle inhibitory potential against HCT116 cells, superior to that of quercetin, used as a positive control.
- Dias, Tatiana A.,Duarte, Cecília L.,Lima, Cristovao F.,Proen?a, M. Fernanda,Pereira-Wilson, Cristina
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p. 500 - 510
(2013/10/01)
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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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- Phenylpropiophenone derivatives as potential anticancer agents: Synthesis, biological evaluation and quantitative structure-activity relationship study
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Series of twelve chalcone and propafenone derivatives has been synthesized and evaluated for anticancer activities against HeLa, Fem-X, PC-3, MCF-7, LS174 and K562 cell lines. The 2D-QSAR and 3D-QSAR studies were performed for all compounds with cytotoxic
- Ivkovi?, Branka M.,Nikolic, Katarina,Ili?, Bojana B.,?i?ak, ?eljko S.,Novakovi?, Radmila B.,?udina, Olivera A.,Vladimirov, Sote M.
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p. 239 - 255
(2013/07/27)
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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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- Ruthenium-NHC-catalyzed asymmetric hydrogenation of flavones and chromones: General access to enantiomerically enriched flavanones, flavanols, chromanones, and chromanols
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Two to four! Readily available flavones and chromones were efficiently converted into four valuable chiral classes of O-heterocycles - flavanones, chromanones, flavanols, and chromanols - by means of an enantioselective Ru/NHC-catalyzed hydrogenation process (see scheme; NHC=N-heterocyclic carbene, PCC=pyridinium chlorochromate). Copyright
- Zhao, Dongbing,Beiring, Bernhard,Glorius, Frank
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supporting information
p. 8454 - 8458
(2013/09/02)
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- MW assisted synthesis of some pyrazoles containing benzotriazole moiety: An environmentally benign approach
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MW assisted synthesis of pyrazoles containing benzotriazole moieties 4a-n has been achieved by cyclocondensation of substituted chalcones 3a-n with hydrazide of benzotriazole 2 in presence of glacial acetic acid (GAA). Thus, synthesized compounds 4a-n have been characterized by their spectral data and evaluated for their antibacterial and antifungal activities against various microbes.
- Tiwari, Urvashi,Ameta, Chetna,Rawal, Manish K.,Ameta, Rakshit,Punjabi, Pinki B.
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p. 432 - 439
(2013/05/08)
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- Rhodium(Cp*) compounds with flavone-derived ligand systems: Synthesis and characterization
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Organometallic rhodium complexes have been reported to exhibit promising anticancer activity and some examples have been investigated more extensively over the last years. Based on recent successes of cytotoxic rhodium compounds, this work describes the synthesis and characterization of organorhodium(III) complexes with 3-hydroxyflavones as bidentate ligands and η5- coordinated pentamethylcyclopentadienyl (Cp*). The organorhodium compounds were synthesized and characterized by means of NMR spectroscopy and single crystals of the compounds were characterized by X-ray diffraction analysis. Interestingly, the rhodium complexes were isolated with methanol or triflate coordinated to the central rhodium atom, yielding positively-charged and neutral complexes, respectively. However, none of the complexes prepared were sufficiently soluble in aqueous media to allow testing their cytotoxicity. Copyright
- Schwarz, Martina B.,Kurzwernhart, Andrea,Roller, Alexander,Kandioller, Wolfgang,Keppler, Bernhard K.,Hartinger, Christian G.
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p. 1648 - 1654
(2013/08/23)
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- Synthesis of some modified aurones as antileukemic and antibacterial agents
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Cyclisation of 1-(2-hydroxyphenyl)-3-substituted phenylprop-2-en-1-ones 1a-h in pyridine with mercuric acetate gives different 2-benzylidene-1- benzofuran-3(2H)-ones 2a-h which on subsequent reaction with hydroxylamine hydrochloride affords 2-benzylidene-
- Deepthi,Harinadha, Babu V,Madhava, Reddy B
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p. 1455 - 1461
(2014/01/06)
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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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