RESUMO
Starting from the enantiopure precursors, a pair of chiral macrocyclic arenes named helic[1]triptycene[3]arenes were conveniently synthesized. The circular dichroism (CD) spectra of the enantiomeric macrocyclic arenes exhibited mirror images, and the X-ray single crystal structures confirmed their absolute conformations as well. Moreover, the macrocyclic arenes showed strong complexation with secondary ammonium and primary ammonium salts containing aminoindan groups. In particular, the chiral macrocyclic arenes exhibited enantioselective recognition ability towards the chiral secondary ammonium salts containing aminoindan groups with an enantioselective ratio up to 3.89.
Assuntos
Antracenos/química , Indanos/química , Estereoisomerismo , Compostos de Amônio/química , Antracenos/síntese química , Dicroísmo Circular , Indanos/síntese químicaRESUMO
A small library of derivatives carrying a polycyclic scaffold recently identified by us as a new privileged structure in medicinal chemistry was designed and synthesized, aiming at obtaining potent MDR reverting agents also endowed with antitumor properties. In particular, as a follow-up of our previous studies, attention was focused on the role of the spacer connecting the polycyclic core with a properly selected nitrogen-containing group. A relevant increase in reverting potency was observed, going from the previously employed but-2-ynyl- to a pent-3-ynylamino moiety, as in compounds 3d and 3e, while the introduction of a triazole ring proved to differently impact on the activity of the compounds. The docking results supported the data obtained by biological tests, showing, for the most active compounds, the ability to establish specific bonds with P-glycoprotein. Moreover, a multifaceted anticancer profile and dual in vitro activity was observed for all compounds, showing both revertant and antitumor effects on leukemic cells. In this respect, 3c emerged as a "triple-target" agent, endowed with a relevant reverting potency, a considerable antiproliferative activity and a collateral sensitivity profile.
Assuntos
Antracenos/farmacologia , Antineoplásicos/farmacologia , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Succinimidas/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antracenos/síntese química , Antracenos/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Hidrocarbonetos Aromáticos com Pontes/síntese química , Hidrocarbonetos Aromáticos com Pontes/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade , Succinimidas/síntese química , Succinimidas/metabolismoRESUMO
Studies have previously shown that anthracene and naphthalene derivatives serve as compounds for trapping and chemically generating singlet molecular oxygen [O2(1Δg)], respectively. Simple and efficient synthetic routes to anthracene and naphthalene derivatives are needed, for improved capture and release of O2(1Δg) in cellular environments. Because of this need, we have synthesized a dihydroxypropyl amide naphthlene endoperoxide as a O2(1Δg) donor, as well as five anthracene derivatives as O2(1Δg) acceptor. The anthracene derivatives bear dihydroxypropyl amide, ester, and sulfonate ion end groups connected to 9,10-positions by way of unsaturated (vinyl) and saturated (ethyl) bridging groups. Heck reactions were found to yield these six compounds in easy-to-carry out 3-step reactions in yields of 50-76%. Preliminary results point to the potential of the anthracene compounds to serve as O2(1Δg) acceptors and would be amenable for future use in biological systems to expand the understanding of O2(1Δg) in biochemistry.
Assuntos
Antracenos/farmacologia , Naftalenos/farmacologia , Oxigênio Singlete/metabolismo , Antracenos/síntese química , Antracenos/química , Linhagem Celular Tumoral , Humanos , Microscopia de Fluorescência , Estrutura Molecular , Naftalenos/síntese química , Naftalenos/química , Imagem Óptica , Oxigênio Singlete/químicaRESUMO
The anthracenone ligands (1-12) with a keto-phenol and a hydroxamic acid unit were synthesized and evaluated by a restriction enzyme inhibition assay. DNA substrates composed of multiple CGCG or CGG sites are fully hydrolyzed by a restriction enzyme that is selective for each sequence. Under such conditions, the full-length DNA substrate remains only when the ligand binds to all binding sites and protects it from hydrolysis by the restriction enzymes. In the assay using AccII and the 50-mer DNA substrates containing a different number of CGCG sites at different non-binding AT base pair intervals, the more the CGCG sites, the more the full-length DNA increased. Namely, simultaneous binding of the ligand (5) to the CGCG sites increased in the order of (CGCG)5>(CGCG)2>(CGCG)1. Furthermore, the length of the spacer of the hydroxamic acid to the anthracenone skeleton played an important role in the preference for the number of the d(A/T) base pairs between the CGCG sites. The long spacer-ligand (5) showed a preference to the CGCG sites with five AT pairs, and the short spacer-ligand (10) to that with two AT pairs. The ligand (12) with the shortest spacer showed a preference in simultaneous binding to the 54-mer DNA composed of 16 continuous CGG sites in the assay using the restriction enzyme Fnu4HI that hydrolyzes the d(GCGGC)/d(CGCCG) site. Application of these ligands to biological systems including the repeat DNA sequence should be of significant interest.
Assuntos
Antracenos/farmacologia , Enzimas de Restrição do DNA/antagonistas & inibidores , Ácidos Hidroxâmicos/farmacologia , Fenóis/farmacologia , Antracenos/síntese química , Antracenos/química , Sítios de Ligação/efeitos dos fármacos , Enzimas de Restrição do DNA/metabolismo , Relação Dose-Resposta a Droga , Ácidos Hidroxâmicos/química , Ligantes , Estrutura Molecular , Fenóis/química , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
Herein, we report the biosynthesis of protein heterocatenanes using a programmed sequence of multiple post-translational processing events including intramolecular chain entanglement, inâ situ backbone cleavage, and spontaneous cyclization. The approach is general, autonomous, and can obviate the need for any additional enzymes. The catenane topology was convincingly proven using a combination of SDS-PAGE, LC-MS, size exclusion chromatography, controlled proteolytic digestion, and protein crystallography. The X-ray crystal structure clearly shows two mechanically interlocked protein rings with intact folded domains. It opens new avenues in the nascent field of protein-topology engineering.
Assuntos
Antracenos/química , Cristalografia por Raios X/métodos , Antracenos/síntese química , Cromatografia Líquida/métodos , Eletroforese em Gel de Poliacrilamida , Espectrometria de Massas , Estrutura Molecular , ProteóliseRESUMO
New hetero-arylidene-9(10H)-anthrone derivatives (1) were synthesized from reaction of 1,2-dimethyl-3-alkyl imidazolium salts (2) and 9-anthracenecarboxaldehyde. Ion exchange of the anion with dioctyl sulfosuccinate and lithium bis(trifluoromethanesulfonyl)imide led to the preparation of other derivatives. The antiproliferative effect of the compounds was evaluated in human ovarian (A2780) and colorectal (HCT116) carcinoma cell lines and in normal primary human fibroblasts. Compound 1 presented an antiproliferative effect related to the imidazolium pattern of substitution with compounds having a decyl group at the R-position (1c and 3c) showing the highest cytotoxic activities in all cell lines independently of the counter ion. Compounds 1b and 1c internalize A2780 cancer cells via a passive or an active transport, respectively, inducing A2780 cell death via an extrinsic apoptosis (1b) or intrinsic apoptosis and oncosis (1c). The localization of both compounds in the cytoplasm coupled to the absence of reactive oxygen species (ROS) induction suggest that the mechanisms of toxicity might be different than those of other anthracyclines currently used in chemotherapy.
Assuntos
Antracenos/farmacologia , Antineoplásicos/farmacologia , Antracenos/síntese química , Antracenos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estrutura Molecular , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-AtividadeRESUMO
Pd-catalysed Stille and Suzuki cross-couplings were used to prepare 9-(3-indenyl)-, 6, and 9-(2-indenyl)-anthracene, 7; addition of benzyne led to the 9-Indenyl-triptycenes, 8 and 9. In 6, [4 + 2] addition also occurred to the indenyl substituent. Reaction of 6 through 9 with Cr(CO)6 or Re2(CO)10 gave their M(CO)3 derivatives, where the Cr or Re was complexed to a six- or five-membered ring, respectively. In the 9-(2-indenyl)triptycene complexes, slowed rotation of the paddlewheel on the NMR time-scale was apparent in the η5-Re(CO)3 case and, when the η6-Cr(CO)3 was deprotonated, the resulting haptotropic shift of the metal tripod onto the five-membered ring also blocked paddlewheel rotation, thus functioning as an organometallic molecular brake. Suzuki coupling of ferrocenylboronic acid to mono- or dibromoanthracene yielded the ferrocenyl anthracenes en route to the corresponding triptycenes in which stepwise hindered rotations of the ferrocenyl groups behaved like molecular dials. CuCl2-mediated coupling of methyl- and phenyl-indenes yielded their rac and meso 2,2'-biindenyls; surprisingly, however, the apparently sterically crowded rac 2,2'-Bis(9-triptycyl)biindenyl functioned as a freely rotating set of molecular gears. The predicted high rotation barrier in 9-phenylanthracene was experimentally validated via the Pd-catalysed syntheses of di(3-fluorophenyl)anthracene and 9-(1-naphthyl)-10-phenylanthracene.
Assuntos
Antracenos/química , Acoplamento Oxidativo , Paládio/química , Antracenos/síntese química , Técnicas de Química Sintética , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/químicaRESUMO
A set of novel Kv7.2/7.3 (KCNQ2/3) channel blockers was synthesized to address several liabilities of the known compounds XE991 (metabolic instability and CYP inhibition) and the clinical compound DMP 543 (acid instability, insolubility, and lipophilicity). Using the anthrone scaffold of the prior channel blockers, alternative heteroarylmethyl substituents were installed via enolate alkylation reactions. Incorporation of a pyridazine and a fluorinated pyridine gave an analog (compound 18, JDP-107) with a promising combination of potency (IC50â¯=â¯0.16⯵M in a Kv7.2 thallium flux assay), efficacy in a Kv7.2/7.3 patch clamp assay, and drug-like properties.
Assuntos
Antracenos/farmacologia , Canal de Potássio KCNQ2/antagonistas & inibidores , Canal de Potássio KCNQ3/antagonistas & inibidores , Transtornos Mentais/tratamento farmacológico , Doenças Neurodegenerativas/tratamento farmacológico , Bloqueadores dos Canais de Potássio/farmacologia , Antracenos/síntese química , Antracenos/química , Relação Dose-Resposta a Droga , Canal de Potássio KCNQ2/metabolismo , Canal de Potássio KCNQ3/metabolismo , Estrutura Molecular , Bloqueadores dos Canais de Potássio/síntese química , Bloqueadores dos Canais de Potássio/química , Relação Estrutura-AtividadeRESUMO
Efficient monosubstitution of the non-iodinated, mono-iodinated and di-iodinated m-carborane cluster at one Ccluster has led to the preparation of three single organic molecule-carborane dyads (4-6), which exhibited exceptional fluorescence properties with quantum yield values of 100% in solution, for all of them, with maxima around 415 nm, which correspond to the locally excited state (LE) emission. These results suggest that simply linking the m-carborane fragment to one anthracene unit through a CH2 spacer produces a significant enhancement of the fluorescence in the final fluorophore, probably due to the free rotation of the anthracene linked to the Ccluster. Besides, the presence of one or two iodine atoms linked to boron atoms does not cause any influence on the photophysical properties of the dyads, as it is confirmed by TD-DFT calculations. Notably, the three conjugates show good fluorescence efficiency in the aggregate state with quantum yields in the range of 19-23%, which could be ascribed to the presence of CH2, particularly for 4, and the iodine atoms in 5 and 6, which prevent π-π stacking. All these results indicate that our dyads are extremely good emitters in solution while maintaining the emission properties in the aggregate state. Crystal packing, fingerprint plot analysis, and TD-DFT calculations for the three compounds support these results. Confocal microscopy studies show that 6 is the best-internalized compound by HeLa cells via endocytosis, although 4 and 5 also presented a high fluorescence intensity emission. Moreover, due to the blue emission, this compound is an excellent candidate to be applied as a fluorescent dye in bioimaging studies.
Assuntos
Antracenos/síntese química , Boranos/síntese química , Corantes Fluorescentes/síntese química , Antracenos/química , Boranos/química , Cristalografia por Raios X , Teoria da Densidade Funcional , Endocitose , Corantes Fluorescentes/química , Células HeLa , Humanos , Microscopia Confocal , Estrutura MolecularRESUMO
An anthracene carboxyimide derivative was synthesized as a colorimetric and fluorogenic sensor to determine NO2- with a rapid response (<4 min), excellent selectivity and a low detection limit (84 nM). Paper strips containing the sensor were applied to visually determine the NO2- content in food.
Assuntos
Antracenos/química , Corantes Fluorescentes/química , Contaminação de Alimentos/análise , Naftalimidas/química , Nitritos/análise , Triazóis/química , Animais , Antracenos/síntese química , Antracenos/efeitos da radiação , Brassica/química , Colorimetria/instrumentação , Colorimetria/métodos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/efeitos da radiação , Luz , Limite de Detecção , Produtos da Carne/análise , Naftalimidas/síntese química , Naftalimidas/efeitos da radiação , Papel , Raphanus/química , Suínos , Triazóis/síntese química , Triazóis/efeitos da radiaçãoRESUMO
A urea derivative L1 exhibits Aggregation-Induced Emission (AIE) activity in an acetonitrile-water mixed solvent. The aggregation phenomenon has been corroborated by microscopy and light scattering studies. The ligand (L1) also displays a selective turn-on fluorescence response towards human serum albumin (HSA) in 100% aqueous medium over various other comparable proteins (even bovine serum albumin (BSA)) and enzymes. The weakly emissive probe L1 showed a substantial increase in emission intensity upon binding with HSA through electrostatic interactions. The good linear relationship between the fluorescence enhancement (I/I0 - 1) and the concentration of HSA provided the scope to attain an impressive detection limit as low as 5 µg mL-1. A drug displacement experiment and molecular docking study were employed to ascertain the likely protein (HSA)-ligand binding interactions.
Assuntos
Corantes Fluorescentes/química , Albumina Sérica Humana/urina , Ureia/análogos & derivados , Antracenos/síntese química , Antracenos/química , Antracenos/metabolismo , Sítios de Ligação , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Humanos , Limite de Detecção , Simulação de Acoplamento Molecular , Naftalenos/síntese química , Naftalenos/química , Naftalenos/metabolismo , Ligação Proteica , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismo , Espectrometria de Fluorescência/métodos , Ureia/síntese química , Ureia/metabolismoRESUMO
Herein, we identify supramolecular self-associating amphiphiles (SSAs) as a novel class of antibacterials with activity towards methicillin-resistant Staphylococcus aureus. Structure-activity relationships have been identified in the solid, solution and gas phases. Finally, we show that when supplied in combination, SSAs exhibit increased antibacterial efficacy against these clinically relevant microbes.
Assuntos
Antracenos/química , Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antracenos/síntese química , Antracenos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Cristalografia por Raios X , Ligação de Hidrogênio , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Microscopia de Fluorescência , Conformação Molecular , Compostos de Amônio Quaternário/química , Relação Estrutura-AtividadeRESUMO
We designed and synthesized several fluorescent nucleotides from thiophene, anthracene and pyrene, which have different sizes, and screened their incorporation and extension capability during the rolling circle amplification of DNA. The thiophene-based fluorescent nucleotide (dUthioTP) could highly incorporate and extended into the rolling circle DNA product, while other fluorescent nucleotides (dUanthTP, and dUpyrTP) could not. This dUthioTP fluorescent nucleotide could be used for the detection of miRNA 24-3P, which is related PRRSV. This direct labeling system during rolling circle DNA amplification exhibited an increased fluorescence signal showing gel formation for the detection of miRNA 24-3P. This direct labeling system is a very simple and cost-efficient method for the detection miRNA 24-3P and also exhibited highly sensitive and selective detection properties.
Assuntos
Antracenos/química , DNA Circular/genética , Corantes Fluorescentes/química , MicroRNAs/análise , Técnicas de Amplificação de Ácido Nucleico , Pirenos/química , Tiofenos/química , Antracenos/síntese química , Relação Dose-Resposta a Droga , Fluorescência , Corantes Fluorescentes/síntese química , Humanos , Estrutura Molecular , Pirenos/síntese química , Relação Estrutura-Atividade , Tiofenos/síntese químicaRESUMO
In this work, we report on the synthesis of two new mono-alkylated tetrandrine derivatives with acridine and anthracene units, MAcT and MAnT. The compounds were fully characterized by physicochemical techniques and single-crystal X-ray diffraction analysis. In addition, both derivatives were studied as nucleotide receptors and double-stranded DNA binders in aqueous phosphate buffer at pHâ¯=â¯7.2 using UV-vis and fluorescence spectroscopy. According to the molecular recognition studies, MAcT and MAnT exhibit high affinity (Kâ¯â¼â¯105â¯M-1) and selectivity for ds-DNA, presumably in an intercalation mode. Finally, the anti-proliferative effects of the tetrandrine derivatives on different cancer cell lines were explored, revealing promising activities. Particularly, the mono-anthracene tetrandrine derivative MAnT showed an IC50 of 2.74⯵g/mL on the HeLa cervical cancer cell line, representing a value 3.3 times smaller than that obtained for unsubstituted tetrandrine. Examination of the cytotoxic effects on the HeLa cell line by inverted microscopy suggests that the cell death mechanism consists basically in apoptosis. The molecular modelling of three ds-DNA-MAcT complexes, suggested that the macrocycles may use an intercalation binding mode towards DNA. MAcT is predicted to bind into the major groove of the ds-DNA providing non-covalent interactions such as electrostatic, van der Waals and hydrophobic interactions that lead to selectivity. Overall experimental data supports the mode of action of MAnT and MAcT as cytotoxic compounds against cancer cell lines via a DNA interaction mechanism.
Assuntos
Acridinas/química , Antracenos/química , Benzilisoquinolinas/química , Compostos Macrocíclicos/síntese química , Células A549 , Acridinas/síntese química , Acridinas/farmacologia , Antracenos/síntese química , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Benzilisoquinolinas/síntese química , Benzilisoquinolinas/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA/química , DNA/metabolismo , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Substâncias Intercalantes/síntese química , Substâncias Intercalantes/química , Substâncias Intercalantes/farmacologia , Compostos Macrocíclicos/química , Compostos Macrocíclicos/farmacologia , Simulação de Acoplamento Molecular , Conformação de Ácido Nucleico , Eletricidade EstáticaRESUMO
Ruthenium polypyridine complexes have shown promise as agents for photodynamic therapy (PDT) and tools for molecular biology (chromophore-assisted light inactivation). To accomplish these tasks, it is important to have at least target selectivity and great reactive oxygen species (ROS) photogeneration: two properties that are not easily found in the same molecule. To prepare such new agents, we synthesized two new ruthenium complexes that combine an efficient DNA binding moiety (dppz ligand) together with naphthyl-modified (1) and anthracenyl-modified (2) bipyridine as a strong ROS generator bound to a ruthenium complex. The compounds were fully characterized and their photophysical and photochemical properties investigated. Compound 2 showed one of the highest quantum yields for singlet oxygen production ever reported (ΦΔ= 0.96), along with very high DNA binding (log Kb = 6.78). Such photochemical behavior could be ascribed to the lower triplet state involving the anthracenyl-modified bipyridine, which is associated with easier oxygen quenching. In addition, the compounds exhibited moderate selectivity toward G-quadruplex DNA and binding to the minor groove of DNA, most likely driven by the pendant ligands. Interestingly, they also showed DNA photocleavage activity even upon exposure to a yellow light-emitting diode (LED). Regarding their biological activity, the compounds exhibited an exciting antibacterial action, particularly against Gram-positive bacteria, which was enhanced upon blue LED irradiation. Altogether, these results showed that our strategy succeeded in producing light-triggered DNA binding agents with pharmacological and biotechnological potential.
Assuntos
Complexos de Coordenação/farmacologia , DNA/química , Substâncias Intercalantes/farmacologia , Rutênio/química , 2,2'-Dipiridil/síntese química , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacologia , 2,2'-Dipiridil/efeitos da radiação , Antracenos/síntese química , Antracenos/química , Antracenos/farmacologia , Antracenos/efeitos da radiação , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/efeitos da radiação , Dano ao DNA , Etídio/farmacologia , Bactérias Gram-Positivas/efeitos dos fármacos , Substâncias Intercalantes/síntese química , Substâncias Intercalantes/química , Substâncias Intercalantes/efeitos da radiação , Ligantes , Luz , Oxigênio/química , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/efeitos da radiação , Espécies Reativas de Oxigênio/síntese químicaRESUMO
Oxovanadium(IV) complexes [VO(L1/L2)Cl2]n+ (1,2) of (anthracenyl)terpyridine (An-tpy as L1 in 1, n=0) and triphenylphosphonium-appended (anthracenyl)terpyridine (An-tpy-TPP+ as L2 in 2, n=1) were synthesized, characterized and their DNA crosslinking ability, photocytotoxicity in visible light and cellular localization in cancer cells studied. The bromide derivative of 2, viz. [VO(An-tpy-TPP)Br2]Br (3) is structurally characterized. The structure showed trans disposition of two halides in the coordination sphere and the TPP+ unit is a pendant to the terpyridyl ligand. The DNA melting and comet assay studies on the complexes suggest the formation of DNA crosslinks. Complexes 1 and 2 displayed ~10 fold increase in cytotoxicity on exposure to visible light (400-700nm) when compared to those in dark in HeLa and MCF-7 cells. FACScan (Fluorescence Associated Cell Sorter Scan) analysis showed cellular apoptosis when treated with the complex in visible light in comparison to their dark controls. Fluorescence microscopic studies using complex 2 revealed its mitochondrial localization within the cancer cells.
Assuntos
Antracenos , Reagentes de Ligações Cruzadas , DNA de Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Fototerapia , Vanadatos , Antracenos/síntese química , Antracenos/química , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Reagentes de Ligações Cruzadas/síntese química , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/farmacologia , Células HeLa , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Neoplasias/metabolismo , Neoplasias/patologia , Vanadatos/síntese química , Vanadatos/química , Vanadatos/farmacologiaRESUMO
Described herein is the enantioselective syntheses of (+)- and (-)-rishirilideâ B from the corresponding optically active ß-substituted tetralones, which were obtained by oxidative kinetic resolution based on α-hydroxylation in the presence of a chiral guanidine-bisurea bifunctional organocatalyst. Benzylic oxidation of the tetralones at C1 followed by regioselective isomerization of the oxabenzonorbornadiene structure led to rishirilideâ B. Our findings lead to the revision of the previously proposed (2R,3R,4R) absolute configuration of (+)-rishirilideâ B to (2S,3S,4S).
Assuntos
Antracenos/síntese química , Compostos Orgânicos/química , Antracenos/química , Compostos de Boro/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Catálise , Cromatografia Líquida de Alta Pressão , Cristalografia por Raios X , Hidroxilação , Cinética , Estrutura Molecular , Oxirredução , Espectroscopia de Prótons por Ressonância Magnética , Estereoisomerismo , Tetralonas/químicaRESUMO
Despite a growing interest in two-dimensional polymers, their rational synthesis remains a challenge. The solution-phase synthesis of a two-dimensional polymer is reported. A DNA-based monomer self-assembles into a supramolecular network, which is further converted into the covalently linked two-dimensional polymer by anthracene dimerization. The polymers appear as uniform monolayers, as shown by AFM and TEM imaging. Furthermore, they exhibit a pronounced solvent responsivity. The results demonstrate the value of DNA-controlled self-assembly for the formation of two-dimensional polymers in solution.
Assuntos
Antracenos/síntese química , Técnicas de Química Sintética/métodos , DNA/síntese química , Polímeros/síntese química , Antracenos/química , Sequência de Bases , DNA/química , Dimerização , Modelos Moleculares , Polímeros/químicaRESUMO
Two-photon microscopy is a powerful tool for studying biological systems. In search of novel two-photon absorbing dyes for bioimaging, we synthesized a new anthracene-based dipolar dye (anthradan) and evaluated its two-photon absorbing and imaging properties. The new anthradan, 9,10-bis(o-dimethoxy-phenyl)-anthradan, absorbs and emits at longer wavelengths than acedan, a well-known two-photon absorbing dye. It is also stable under two-photon excitation conditions and biocompatible, and thus used for two-photon imaging of mouse organ tissues to show bright, near-red fluorescence along with negligible autofluorescence. Such an anthradan thus holds promise as a new class of two-photon absorbing dyes for the development of fluorescent probes and tags for biological systems.
Assuntos
Antracenos/química , Antracenos/síntese química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Imagem Óptica , Fótons , Animais , Encéfalo/diagnóstico por imagem , Rim/diagnóstico por imagem , Fígado/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Camundongos , Estrutura Molecular , Fenômenos Ópticos , Teoria Quântica , Baço/diagnóstico por imagemRESUMO
The consequence of unpaired electrons in organic molecules has fascinated and confounded chemists for over a century. The study of open-shell molecules has been rekindled in recent years as new synthetic methods, improved spectroscopic techniques and powerful computational tools have been brought to bear on this field. Nonetheless, it is the intrinsic instability of the biradical species that limits the practicality of this research. Here we report the synthesis and characterization of a molecule based on the diindeno[b,i]anthracene framework that exhibits pronounced open-shell character yet possesses remarkable stability. The synthetic route is rapid, efficient and possible on the gram scale. The molecular structure was confirmed through single-crystal X-ray diffraction. From variable-temperature Raman spectroscopy and magnetic susceptibility measurements a thermally accessible triplet excited state was found. Organic field-effect transistor device data show an ambipolar performance with balanced electron and hole mobilities. Our results demonstrate the rational design and synthesis of an air- and temperature-stable biradical compound.