644-78-0Relevant academic research and scientific papers
Photo- and pH-induced transformations of flavylium cation: 'Write-lock- read-unlock-erase' cycles
Pina, Fernando,Melo, Maria Jo?o,Maestri, Mauro,Passaniti, Paolo,Camaioni, Nadia,Balzani, Vincenzo
, p. 3199 - 3207 (1999)
The structural transformations of flavylium ion in aqueous solutions caused by pH jumps and photoexcitation have been investigated. At pH +). By increasing pH, the concentration of AH+ decreases and, at pH = 5, this form is no longer present. The species obtained immediately after a pH jump undergo transformation processes with pH-dependent rate constants. At pH = 5.2 and 20 °C, the final product is the uncolored trans-chalcone (C(t)). This form can be transformed by light excitation into the cis-chalcone (C(c)) isomer, which is in equilibrium with the hemiacetal form (B(2)). This mixture is relatively inert due to the existence of a kinetic barrier that slows down the back thermal isomerization of C(c) to the stable C(t) form. Such a back reaction to C(t) can be totally prevented if the irradiated solution is submitted to a pH jump to pH = 1, which transforms the photoproducts into the stable AH+ species. In basic solution, two more species were detected, namely the anionic forms C(c)- and C(t)- of the cis and trans chalcone. C(t)- is a stable, not photosensitive and luminescent species, whereas C(c)- is not stable, being converted into C(t)- in the dark. The photochemical and pH- induced transformations of the flavylium cation in the pH range 0-11 can be taken as a basis to design write-lock-read-unlockerase cycles for an optical molecular-level memory with multiple readout capacity.
Novel triazine centred manganese based complex: A photophysical and biological studies
Alphonse,Tharmaraj,Josephine, B. Avila,Teresita, V. Mary
, p. 91 - 94 (2020)
In this work, Mn(II) complex of triazine based ligand has been synthesized and characterized using various physico-chemical methods including C,H,N elemental analysis, FT-IR,1H NMR and EI-mass analysis. The synthesized compounds serve as potential photoactive material as indicated from its characteristic fluorescent properties. The ligand and its metal complex were assayed for in vitro antimicrobial activity on four bacterial strains (S. aureus, B. subtilis, E. coli and K. pneumoniae) using well-diffusion method and it was observed that metal complex showed enhanced antimicrobial activity against all tested strains as compared to ligand.
Formal cycloaddition of ethyl 2-aroyl-1-chlorocyclopropanecarboxylates:facile synthesis of diversified tetrahydrocyclopropa[b]chromenes
Xiong, Guoxi,Liao, Yong,Liu, Xue-Hui,Tang, Xiangying,Gong, Yuefa
, p. 1486 - 1491 (2018)
Tandem reaction of ortho-hydroxy chalcone with ethyl 2-aroyl-1-chlorocyclopropanecarboxylates has been disclosed, affording facile synthesis of diversified tetrahydrocyclopropa[b]chromenes via electron-deficient cyclopropene intermediate.
Laser flash photolysis studies of the photo-ring-opening reaction of flav-3-en-2-ol
Horiuchi, Hiroaki,Yokawa, Akinobu,Okutsu, Tetsuo,Hiratsuka, Hiroshi
, p. 2429 - 2435 (1999)
Electronic structure and photodynamics of flav-3-en-2-ol have been studied by steady-state and time-resolved absorption measurements, and by semi-empirical MO calculations. The photo-ring-opening reaction to produce 2- hydroxychalcone has been determined to be a monophotonic process with the quantum yield of 0.29. The precursor to 2-hydroxychalcone has been assigned to the ground-state enol-form by nanosecond laser flash photolysis study at room temperature and steady-state photolysis study at 77 K. The efficiency of the tautomerization from the ground-state enol-form to keto-form of 2- hydroxychalcone has been estimated to be unity. The enol-form is transformed into 2-hydroxychalcone with the rate constant of 3.2x 104 s-1 in neat acetonitrile, and this process is accelerated by protic molecules. The PM3 calculation of flav-3-en-2-ol showed that the dissociative potential surface in the first excited singlet-state is responsible for the ring-opening reaction.
Combined 3D-QSAR and docking analysis for the design and synthesis of chalcones as potent and selective monoamine oxidase B inhibitors
Mellado, Marco,González, César,Mella, Jaime,Aguilar, Luis F.,Vi?a, Dolores,Uriarte, Eugenio,Cuellar, Mauricio,Matos, Maria J.
, (2021/02/12)
Monoamine oxidases (MAOs) are important targets in medicinal chemistry, as their inhibition may change the levels of different neurotransmitters in the brain, and also the production of oxidative stress species. New chemical entities able to interact selectively with one of the MAO isoforms are being extensively studied, and chalcones proved to be promising molecules. In the current work, we focused our attention on the understanding of theoretical models that may predict the MAO-B activity and selectivity of new chalcones. 3D-QSAR models, in particular CoMFA and CoMSIA, and docking simulations analysis have been carried out, and their successful implementation was corroborated by studying twenty-three synthetized chalcones (151–173) based on the generated information. All the synthetized molecules proved to inhibit MAO-B, being ten out of them MAO-B potent and selective inhibitors, with IC50 against this isoform in the nanomolar range, being (E)-3-(4-hydroxyphenyl)-1-(2,2-dimethylchroman-6-yl)prop-2-en-1-one (152) the best MAO-B inhibitor (IC50 of 170 nM). Docking simulations on both MAO-A and MAO-B binding pockets, using compound 152, were carried out. Calculated affinity energy for the MAO-A was +2.3 Kcal/mol, and for the MAO-B was ?10.3 Kcal/mol, justifying the MAO-B high selectivity of these compounds. Both theoretical and experimental structure–activity relationship studies were performed, and substitution patterns were established to increase MAO-B selectivity and inhibitory efficacy. Therefore, we proved that both 3D-QSAR models and molecular docking approaches enhance the probability of finding new potent and selective MAO-B inhibitors, avoiding time-consuming and costly synthesis and biological evaluations.
Synthesis, characterization and α-amylase and α-glucosidase inhibition studies of novel vanadyl chalcone complexes
Kaur, Mandeep,Kaushal, Raj
, (2020/10/06)
A series of chalcone ligands and their corresponding vanadyl complexes of composition [VO (LI–IV)2(H2O)2]SO4 (where LI = 1,3-Diphenylprop-2-en-1-one, LII = 3-(2-Hydroxy-phenyl)-1-phenyl-propenone, LIII = 3-(3-Nitro-phenyl)-1-phenyl-propenone, LIV = 3-(4-Methoxy-phenyl)-1-phenyl-propenone) have been synthesized and characterized using various spectroscopic (Fourier-transform infrared, electrospray ionization mass, nuclear magnetic resonance, electron paramagnetic resonance, thermogravimetric analysis, vibrating sample magnetometer) and physico-analytic techniques. Antidiabetic activities of synthesized complexes along with chalcones were evaluated by performing in vitro and in silico α-amylase and α-glucosidase inhibition studies. The obtained results displayed moderate to significant inhibition activity against both the enzymes by vanadyl chalcone complexes. The most potent complexes were further investigated for the enzyme kinetic studies and displayed the mixed inhibition for both the enzymes. Further, antioxidant activity of vanadyl chalcone complexes was evaluated for their efficiency to release oxidative stress using 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay, and two complexes (Complexes 2 and 4) have demonstrated remarkable antioxidant activity. All the complexes were found to possess promising antidiabetic and antioxidant potential.
Synthesis of sulfonamides bearing 1,3,5-triarylpyrazoline and 4-thiazolidinone moieties as novel antimicrobial agents
Thach, Thi-Dan,Le, Thi Tuong-Vi,Nguyen, Huu Thien-An,Dang, Chi-Hien,Dang, Van-Su,Nguyen, Thanh-Danh
, p. 158 - 162 (2020/05/08)
Two series of sulfonamides were synthesized from 4-hydrazinylben-zenesulfonamide as the key starting material. 1,3,5-Triarylpyrazoline sulfonamides (2a-i) were obtained by cyclocondensation of various chalcones in 53-64 % yields, while 4-thiazolidinone derivatives (4a-e) were synthesized by cyclocondensation between mercaptoacetic acid and different phenylhydrazones in 43-62 % yields. The synthesized compounds were characterized based on FTIR, 1H-NMR, 13C-NMR and HRMS data. The sulfonamides were evaluated for their in vitro antimicrobial activities against four bacterial strains (E. coli, P. aeruginosa, B. subtillis and S aureus), two filamentous fungal strains (A. Niger and F. oxysporum) and two yeast strains (C. albicans and S. cerevisiae). Seven pyrazolines, 2a-c and 2e-h, exhibited significant inhibition of different microbial strains. Among them, compound 2b displayed good antifungal activity against A. Niger (MIC value at 12.5 μg mL-1) over the reference drug.
Novel isoniazid-spirooxindole derivatives: design, synthesis, biological evaluation, in silico ADMET prediction and computational studies
Bhoi, Manoj N.,Borad, Mayuri A.,Jethava, Divya J.,Pandya, Himanshu A.,Patel, Chirag N.,Patel, Hitesh D.
, (2020/07/21)
In the present scenario, the Synthesis of new and desired antimycobacterial agent has an eternal demand to resist Mycobacterium tuberculosis (MTB). The design and identification of new molecules for the treatment of tuberculosis is an important task in organic as well as medicinal chemistry research. In the present study, we have reported the combination of the desired compound using two versatile and significant moieties, isoniazid and spirooxindole derivatives. A series of novel isoniazid-spirooxindole hybrid molecules (6a-6ao) were designed, synthesized, and well-characterized by various spectroscopic methods. We have evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) strain and MDR-TB. Among them, Compound 6ab was found to be the most effective compare to other compounds. ADMET-related descriptors were to be calculated of all the compounds to predict the pharmacokinetic properties for the selection of the effective and bioavailable compounds. In addition, molecular docking and molecular dynamics studies reveal that the binding modes of all the compounds in the active site of isoniazid-resistant enoyl-ACP(COA) reductase, which helped to establish a structural basis of inhibition of Mycobacterium tuberculosis.
Highly enantioselective addition of aliphatic aldehydes to 2-hydroxychalcone enabled by cooperative organocatalysts
Chen, Le,Chen, Lu,Gao, Yu-Qi,Hou, Yi,Hu, Jiadong,Wen, Wen,Xie, Weiqing,Xu, Dongyang
supporting information, p. 10018 - 10021 (2020/09/15)
Herein, we developed an enantioselective addition of aliphatic aldehydes to 2-hydroxychalcone promoted by cooperative organocatalysts, giving access to hybrid flavonoids in excellent enantioselectivities. This reaction took advantage of cycloisomerization of 2-hydroxychalcone to form a transient flavylium under the irradiation of 24 W CFL, which was trapped by the in situ generated chiral enamine intermediate. The synergistic action of chiral phosphoric acid secured the excellent outcome of this reaction by ion-pairing with the transient flavylium.
Development of 5-(Aryl)-3-phenyl-1H-pyrazole Derivatives as Potent Antimicrobial Compounds
Nagendra Chowdary,Umashankara,Dinesh,Girish,Ramesha Baba
, p. 45 - 50 (2018/12/11)
A series of 16 chalcone compounds were synthesized by Claisen-Schmidt condensation of various aldehydes with acetophenone using KOH as a base in ethanol. The reaction affords the desired products in good yields. Then all the 16 compounds were converted into pyrazoles by treating with hydrazine hydrate in ethanol under reflux condition. Both chalcones and pyrazoles were screened for their in vitro antibacterial (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) and antifungal (Aspergillus flavus, Chrysosporium keratinophilum and Candida albicans) activity. Biological activities of these compounds were compared with those of commercially available antibiotic ampicillin and antifungal agent miconazole. Pyrazoles were found to be most active and effective than corresponding chalcones for antimicrobial activity. Out of the 7 pyrazole compounds tested for antibacterial and antifungal activity, 5 compounds, 4h, 4j, 4l, 4m and 4n are turned out to be potent antimicrobial agents. Therefore these derivatives could serve as a highly promising molecules for further development.
