Correlations Des DéPlacements Chimiques En Rmn <sup>13</sup>C De ComposéS Carbonyles, Thiocarbonyles Et Selenocarbonyles

Schneider, Manfred; Gil, Marie J.; Reliquet, Alain; Meslin, J. C.; Levillain, Jocelyne; Vazeux, Michel; Jury, D.; Mieloszynski, J. L.; Paquer, D.

doi:10.1080/10426509808545470

Cited by 9 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further crucial evidence for selenocarbonyl existence was provided by 77 Se NMR, where signals at 815.2 and 768.3 ppm were obtained for SeCry ( 8 ) and SePQue ( 7 ), respectively, which are in accordance with the 77 Se NMR shifts of selenocarbonyl groups reported in the literature . Moreover, despite the use of different solvents, it is noticeable that 13 C NMR signals observed for the C-4 position of 7 and 8 present the expected downfield shift as compared with the parent oxo-derivatives . Furthermore, definitive proof of SePQue ( 7 ) formation was obtained by X-ray diffraction.…”

Section: Resultssupporting

confidence: 81%

“…42 Moreover, despite the use of different solvents, it is noticeable that 13 C NMR signals observed for the C-4 position of 7 and 8 present the expected downfield shift as compared with the parent oxo-derivatives. 43 Furthermore, definitive proof of SePQue (7) formation was obtained by X-ray diffraction. This compound crystallizes in acetone in a monoclinic P2 1 /c space group: a = 13.8279 (19) Å; b = 15.465(2) Å; c = 7.9179(11) Å; α = 90°; β = 90.154(7)°; γ = 90°; V = 1693.2(4) Å 3 ; Z = 4.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Selenium-Containing Chrysin and Quercetin Derivatives: Attractive Scaffolds for Cancer Therapy

et al. 2015

View full text Add to dashboard Cite

Selenium-containing chrysin (SeChry) and 3,7,3',4'-tetramethylquercetin (SePQue) derivatives were synthesized by a microwave-based methodology. In addition to their improvement in terms of DPPH scavenging and potential GPx-like activities, when tested in a panel of cancer cell lines both selenium-derivatives revealed consistently to be more cytotoxic when compared with their oxo and thio-analogues, evidencing the key role of selenocabonyl moiety for these activities. In particular, SeChry elicited a noteworthy cytotoxic activity with mean IC50 values 18- and 3-fold lower than those observed for chrysin and cisplatin, respectively. Additionally, these seleno-derivatives evidenced an ability to overcome cisplatin and multidrug resistance. Notably, a differential behavior toward malignant and nonmalignant cells was observed for SeChry and SePQue, exhibiting higher selectivity indexes when compared with the chalcogen-derivatives and cisplatin. Our preliminary investigation on the mechanism of cytotoxicity of SeChry and SePQue in MCF-7 human mammary cancer cells demonstrated their capacity to efficiently suppress the clonal expansion along with their ability to hamper TrxR activity leading to apoptotic cell death.

show abstract

Section: Resultssupporting

confidence: 81%

Section: ■ Results and Discussionmentioning

confidence: 99%

Selenium-Containing Chrysin and Quercetin Derivatives: Attractive Scaffolds for Cancer Therapy

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The exception of the series is 3d which has a deshielded signal for CS due to the neighboring α-CF 3 group. Likewise, the δ( 13 C) values of the CSe bonds are within the range reported for other compounds featuring selenium carbonyls attached to amide groups (202–206 ppm) …”

Section: Resultsmentioning

confidence: 99%

“…Likewise, the δ( 13 C) values of the CSe bonds are within the range reported for other compounds featuring selenium carbonyls attached to amide groups (202−206 ppm). 52 The solid-state structure of 3a resolved by X-ray diffraction (Figure 1) reveals a Z-conformation typically associated with Naryl substituted β-enaminoketones. Compared to the βdiketiminate analogue of 3a, the replacement of a N-phenyl group with S causes a distinctive distortion at the C(α)S center as typified by a wide C4−C3−C1 bond angle, indicating a high degree of s-bonding character at the β-C site and supported by the extensive deshielding at this position as observed by 1 H NMR.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Comprehensive Experimental and Computational Study of η⁶-Arene Ruthenium(II) and Osmium(II) Complexes Supported by Sulfur Analogues of the β-Diketiminate Ligand

et al. 2018

View full text Add to dashboard Cite

In comparison to β-diketiminates, a highly exploited class of N,N-chelating ligands, the corresponding βthioketoiminates, monothio-substituted analogues, have received only minor attention. β-Thioketoiminates are straightforwardly prepared through treatment of an appropriate β-ketoiminate with Lawesson's reagent. Employing standard synthetic techniques for η 6 -arene Ru(II) and Os(II) β-diketiminate complexes, an analogous series of chlorido-metal complexes supported by different sized N-aryl substituted β-thioketoiminate ligands is reported. However, metal ligation of a β-thioketoiminate bearing an electron-withdrawing CF 3 group was not possible. The metal− chlorine bond in these complexes is readily activated by various sodium or silver salts of weakly coordinating anions, affording coordinately unsaturated cationic formally 16-electron species. All η 6 -C 6 H 6 metal β-thioketoiminate complexes were characterized by NMR and in the solid state using single crystal X-ray diffraction techniques. Structural studies reveal that incorporation of a thio-group induces substantial bond angle distortion within the metallocycle. The reactivity of the cationic η 6 -C 6 H 6 Ru(II) β-thioketoiminate complexes toward alkynes and isonitriles is analogous to that of the β-diketiminate species. Specifically, the reaction with 1-hexyne results in a [4 + 2] cycloaddition involving the metal and β-C sites, while reaction with isonitrile completely displaces the η 6 -C 6 H 6 ligand. A comprehensive DFT study employing charge decomposition analysis (CDA) reveals a strong covalent metal−sulfur bond which dominates the metal β-thioketoiminate interaction. The M−S bond (M = Ru or Os) is strengthened by charge transfer from metal to sulfur, in contrast to the β-diketiminate species where back electron donation from the metal to the nitrogen centers is negligible. The first reported β-selenoketoiminate was prepared by reacting a β-ketoiminate with the Woolins' reagent. However, this seleno-analog demonstrated significant instability with respect to hydrolysis, and coordination to an η 6 -arene Ru(II) or Os(II) moiety proved unsuccessful.

show abstract

“…The most noticeable differences in the NMR spectra were the downfield shifts of signals corresponding to positions C5, C6 and C10 ( Table 2 ) in 6-selenocaffeine, as compared with caffeine. Indeed the low field chemical shift of the selenocarbonyl carbon atom was already expected [ 25 ].…”

Section: Resultsmentioning

confidence: 81%

Synthesis and Biological Activity of 6-Selenocaffeine: Potential Modulator of Chemotherapeutic Drugs in Breast Cancer Cells

Martins¹,

Miranda

Oliveira

et al. 2013

Molecules

View full text Add to dashboard Cite

We report the development of a new microwave-based synthetic methodology mediated by Woollins’ reagent that allowed an efficient conversion of caffeine into 6-selenocaffeine. A preliminary evaluation on the modulation of antioxidant activity upon selenation of caffeine, using the DPPH assay, indicated a mild antioxidant activity for 6-selenocaffeine, contrasting with caffeine, that exhibited no antioxidant activity under the same experimental conditions. Interestingly, whereas 6-selenocaffeine has revealed to have a low cytotoxic potential in both MCF10A and MCF-7 breast cells (24 h, up to 100 µM, MTT assay), a differential effect was observed when used in combination with the anticancer agents doxorubicin and oxaliplatin in MCF-7 breast cancer cells. The co-treatment of doxorubicin (1 µM) and 6-selenocaffeine (100 µM) resulted in a slight decrease in cellular viability when compared to doxorubicin (1 µM) alone. Conversely, the seleno-caffeine derivative at the same concentration markedly increased the viability of oxaliplatin (100 µM)-treated cells (p < 0.01). Overall, this work highlights an emerging methodology to synthesize organoselenium compounds and points out the differential roles of 6-selenocaffeine in the modulation of the cytotoxicity of anticancer agents.

show abstract

Correlations Des DéPlacements Chimiques En Rmn ¹³C De ComposéS Carbonyles, Thiocarbonyles Et Selenocarbonyles

Cited by 9 publications

References 10 publications

Selenium-Containing Chrysin and Quercetin Derivatives: Attractive Scaffolds for Cancer Therapy

Selenium-Containing Chrysin and Quercetin Derivatives: Attractive Scaffolds for Cancer Therapy

Comprehensive Experimental and Computational Study of η⁶-Arene Ruthenium(II) and Osmium(II) Complexes Supported by Sulfur Analogues of the β-Diketiminate Ligand

Synthesis and Biological Activity of 6-Selenocaffeine: Potential Modulator of Chemotherapeutic Drugs in Breast Cancer Cells

Contact Info

Product

Resources

About

Correlations Des DéPlacements Chimiques En Rmn 13C De ComposéS Carbonyles, Thiocarbonyles Et Selenocarbonyles

Cited by 9 publications

References 10 publications

Selenium-Containing Chrysin and Quercetin Derivatives: Attractive Scaffolds for Cancer Therapy

Selenium-Containing Chrysin and Quercetin Derivatives: Attractive Scaffolds for Cancer Therapy

Comprehensive Experimental and Computational Study of η6-Arene Ruthenium(II) and Osmium(II) Complexes Supported by Sulfur Analogues of the β-Diketiminate Ligand

Synthesis and Biological Activity of 6-Selenocaffeine: Potential Modulator of Chemotherapeutic Drugs in Breast Cancer Cells

Contact Info

Product

Resources

About

Correlations Des DéPlacements Chimiques En Rmn ¹³C De ComposéS Carbonyles, Thiocarbonyles Et Selenocarbonyles

Comprehensive Experimental and Computational Study of η⁶-Arene Ruthenium(II) and Osmium(II) Complexes Supported by Sulfur Analogues of the β-Diketiminate Ligand