- A new synthesis of corannulene
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Flash vacuum pyrolysis of 2-substituted benzo[c]phenanthrene has been exploited as a pivotal step in a new, simple synthesis of the 'bowl-shaped' hydrocarbon corannulene 1.
- Mehta, Goverdhan,Panda, Gautam
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- Substituted dienes prepared from betulinic acid – Synthesis, cytotoxicity, mechanism of action, and pharmacological parameters
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A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC50 and almost complete inhibition at 5 × IC50. Interestingly, compound 4.39 at 5 × IC50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug.
- Frydrych, Ivo,Urban, Milan,?arek, Jan,Benická, Sandra,D?ubák, Petr,Gurská, Soňa,Hajdúch, Marián,Kotulová, Jana,Li?ková, Barbora,Olejníková, Denisa,Pokorny, Jan
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- One-pot synthesis of gem-difluorostyrenes from benzyl bromide via olefination of phosphonium ylide with difluorocarbene
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A new approach for the synthesis of gem-difluorostyrenes from benzyl bromide is described. Quaternization of triphenylphosphine with benzyl bromide to give phosphonium salts, deprotonation of the corresponding phosphonium salts to produce phosphonium ylide, and the subsequent olefination of phosphonium ylide with difluorocarbene generated from difluoromethylene phosphobetaine (Ph3P+CF2CO2-) by decarboxylation can occur smoothly in one-pot, furnishing the final gem-difluorostyrenes in good yields.
- Deng, Xiao-Yun,Lin, Jin-Hong,Xiao, Ji-Chang
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p. 116 - 120
(2015/11/10)
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- Synthesis of a Heparan Sulfate Mimetic Library Targeting FGF and VEGF via Click Chemistry on a Monosaccharide Template
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A disulfated methyl 6-azido-6-deoxy-α-D-mannopyranoside template was used as a core structure for binding to the angiogenic growth factors FGF-1, FGF-2, and VEGF. The core structure was diversified in a rapid, parallel manner by employing the CuI-catalyzed Huisgen azide-alkyne cycloaddition ("click") reaction. The diversity was further extended by incorporating a Swern oxidation-Wittig reaction sequence on a click adduct of propargyl alcohol. Thus, the sulfated core was linked by various spacers to selected hydrophobic or polar motifs, which were designed to probe the protein surface surrounding the cationic heparan sulfate binding sites of the growth factors in order to improve affinity and selectivity. The affinities of the compounds for the growth factors were measured by surface plasmon resonance solution affinity assays. A lead compound was identified with micromolar binding affinity toward both FGF-1 and VEGF (Kd=84 and 49μM, respectively) and good selectivity over FGF-2 (29- and 51-fold, respectively).
- Liu, Ligong,Li, Caiping,Cochran, Siska,Jimmink, Shane,Ferro, Vito
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p. 1267 - 1275
(2012/08/08)
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- Synthesis and characterisation of [6]-azaosmahelicenes: The first d 4-heterometallahelicenes
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[6]-Azaosmahelicenes, the first d4-heterometallahelicenes, have been synthesised and fully characterised. Their optical properties (UV-Vis absorption and luminescence) are reported.
- Crespo, Olga,Eguillor, Beatriz,Esteruelas, Miguel A.,Fernandez, Israel,Garcia-Raboso, Jorge,Gomez-Gallego, Mar,Martin-Ortiz, Mamen,Olivan, Montserrat,Sierra, Miguel A.
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supporting information; experimental part
p. 5328 - 5330
(2012/06/30)
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- A Facile and New Route for the Synthesis of Substituted 1,2-Dithiafulvenes Using Phosphonium Ylides
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A wide variety of 6-aryl-5-phenyl-1,2-dithiafulvenes and 6-aroyl-5-phenyl-1,2-dithiafulvenes (4) have been synthesized by the interaction of 5-phenyl-1,2-dithiol-3-one (3a) and phosphonium ylides (2).The synthesis of these dithiafulvenes has also been car
- Gupta, K. C.,Saxena, B. K.,Pathak, P. K.
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p. 312 - 314
(2007/10/02)
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