- A new, efficient and chemoselective one-pot protocol for synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones from aryl aldehyde bisulfite adducts promoted by POCl3
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(Chemical Equation Presented) A one-pot procedure for the synthesis of 4-arylidene-2-phenyl-5(4H)oxazolones directly from aryl aldehyde bisulfite adducts in the absence of Ac2O in good to excellent yields using phosphoryl chloride is reported. In addition, the observed chemoselectivity can be considered as a noteworthy advantage of this method.
- Khosropour, Ahmad R.,Khodaei, Mohammad M.,Hoseini Jomor, Seyed J.
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- Synthesis and spectral properties of 4-(2,5-dimethoxyphenylmethelene)-2- phenyl-5-oxazolone (DMPO)
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An interesting flourophore, 4-(2,5-dimethoxyphenylmethelene)-2-phenyl-5- oxazolone (DMPO) was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5-dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4-(2,5-dimethoxy-phenylmethelene)-2-phenyl-5-oxazolone (DMPO) were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of molecules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B-type class of Steven's Classification. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.
- El-Daly, Samy A.,Asiri, Abdullah M.,Alamry, Khalid A.,Hussein, Mahmoud A.
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- Dual-Self-Restricted GFP Chromophore Analogues with Significantly Enhanced Emission
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The tremendous gap of fluorescence emission of synthetic green fluorescent protein (GFP) chromophore to the protein itself makes it impossible to use for applications in molecular and cellular imaging. Here, we developed an efficient methodology to enhance the photoluminescence response of synthetic GFP chromophore analogues by constructing dual-self-restricted chromophores. Single self-restricted chromophores were first generated with 2,5-dimethoxy substitution on the aromatic ring, which were further modified with phenyl or 2,5-dimethoxy phenyl to form dual-self-restricted chromophores. These two chromophores showed an obvious solvatofluorochromic color palette across blue to yellow with a maximum emission Stokes shift of 95 nm and dramatically enhanced fluorescence emission in various aprotic solvents, especially in hexane, where the QY reached around 0.6. Importantly, in acetonitrile and dimethyl sulfoxide, the fluorescence QYs of both chromophores were over 0.22, which were the highest reported so far in high polar organic solvents. Meanwhile, the fluorescence lifetimes also improved obviously with the maximum of around 4.5 ns. Theoretical calculations revealed a more favorable Mülliken atomic charge translocation over the double-bond bridge and illustrated much higher energy barriers for the Z/E photoisomerization together with larger bond orders compared with the GFP core chromophore, p-HBDI. Our work significantly improved the fluorescence emission of synthetic GFP chromophore analogues in polar solvents while reserved the multicolor emitting function, providing a solid molecular motif for engineering high-performance fluorescent probes.
- Deng, Hongping,Yu, Chunyang,Yan, Deyue,Zhu, Xinyuan
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p. 871 - 880
(2020/02/28)
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- Synthesis, biological evaluation and in silico studies with 4-benzylidene-2-phenyl-5(4H)-imidazolone-based benzenesulfonamides as novel selective carbonic anhydrase IX inhibitors endowed with anticancer activity
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In the presented work, we report the synthesis of a series of 4-benzylidene-2-phenyl-5(4H)-imidazolone-based benzenesulfonamides 7a-f via the Erlenmeyer–Pl?chl reaction. All the prepared imidazolones 7a-f were evaluated as inhibitors of human (h) carbonic anhydrases (CA, EC 4.2.1.1) cytosolic isoforms hCA I and II, as well as transmembrane tumor-associated isoforms hCA IX and XII. All the tested hCA isoforms were inhibited by the prepared imidazolones 7a-f in variable degrees with the following KIs ranges: 673.2–8169 nM for hCA I, 61.2–592.1 nM for hCA II, 23–155.4 nM for hCA XI, and 21.8–179.6 nM for hCA XII. In particular, imidazolones 7a, 7e, and 7f exhibited good selectivity towards the tumor-associated isoforms (CAs IX and XII) over the off-target cytosolic (CAs I and II) with selectivity index (SI) in the range of 6.2–19.4 and 3.3–8, respectively. Moreover, imidazolones 7a-f were screened for their anticancer activity in one dose (10?5 M) assay against a panel of 60 cancer cell lines according to US-NCI protocol. Furthermore, 7a, 7e and 7f were evaluated for their anti-proliferative activity against colorectal cancer HCT-116 and breast cancer MCF-7 cell lines. Furthermore, 7e and 7f were screened for cell cycle disturbance and apoptosis induction in HCT-116 cells. Finally, a molecular docking study was carried out to rationalize the obtained results.
- Eldehna, Wagdy M.,Abdelrahman, Mohamed A.,Nocentini, Alessio,Bua, Silvia,Al-Rashood, Sara T.,Hassan, Ghada S.,Bonardi, Alessandro,Almehizia, Abdulrahman A.,Alkahtani, Hamad M.,Alharbi, Amal,Gratteri, Paola,Supuran, Claudiu T.
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- Synthesis, bioassay, crystal structure and ab initio studies of Erlenmeyer azlactones
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Several 4-arylidene-2-phenyl-5(4H)-azlactones have been synthesized via Erlenmeyer method. The synthesized compounds have been characterized on the basis of systematic spectral studies (IR, 1H NMR, 13C NMR, and MS). The compound (4Z)
- Parveen, Mehtab,Ali, Akhtar,Ahmed, Sarfaraz,Malla, Ali Mohammed,Alam, Mahboob,Pereira Silva,Silva, Manuela Ramos,Lee, Dong-Ung
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p. 538 - 545
(2013/03/14)
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- Synthesis and anti-inflammatory activity of imidazo[1,2-a] pyridinyl/pyrazinyl benzamides and acetamides
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The present study involves synthesis and determination of anti-inflammatory activity of a series of imidazo[1,2-a]pyridinyl/pyrazinyl benzamides and acetamides. Sixteen new imidazo[1,2-a]pyridinyl/pyrazinyl benzamides and acetamides have been prepared by the ring opening of 4-arylidene-2-methyl/ phenyloxazolones with 2-amino azaheterocycles. All the compounds show significant anti-inflammatory activity. The anti-inflammatory activity studies reveal that both acetamide and benzamide derivatives are equally active. Among the two classes of compounds, i.e., imidazo[1,2-a]pyridine and imidazo[1,2-a]pyrazines, the latter show better activity.
- Hemasrilatha,Sruthi,Manjula,Harinadha Babu,Vittal Rao
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p. 981 - 987
(2012/09/22)
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- Efficient and chemoselective conversion of aryl aldehydes to their azalactones catalysed by Bi(III) salts under solvent free conditions
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Bi(NO3)3.5H2O, Bi(TFA)3 and Bi(OTf)3 were found to be highly powerful and practical catalysts for the synthesis of azalactones under solvent free conditions with excellent yields. In addition, high ch
- Khodaei, Mohammad Mehdi,Khosropour, Ahmad Reza,Jomor, Saied Jabar Hoseini
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p. 638 - 641
(2007/10/03)
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