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1.
J Chromatogr A ; 1625: 461280, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709331

RESUMO

Polysaccharide-based chiral stationary phases (CSPs) are outstandingly suitable to play a key role in chiral HPLC method selection strategies, since they provide high success rates. One reason for this ability is that they adopt a diversity of higher order structures in various eluents, resulting in versatile chiral environments. A potential to extend this versatility further was expected and examined in the present study, based on the recently discovered hysteretic behavior of a widely used chiral selector (CS), amylose tris(3,5-dimethylphenylcarbamate). The hindered transitions of its structure, which are behind the history dependence of its separation ability, were used as a tool to identify distinct states of the chiral selector in order to exploit an extended selectivity space. The identification was carried out using a single diagnostic compound, as opposed to the common approach where testing a library of compounds is required. Eluent mixtures consisting of 2-propanol and either methanol or ethanol were scrutinized in terms of stability and robustness of the observed retentions. The solvent mixtures that were eligible for practical application in these respects were used to construct a screening sequence, including identical compositions combined with different column pretreatment. The gain achievable by using the proposed sequence was then evaluated using 15 enantiomer pairs with focus on resolution, enantiomer elution order and chemoselectivity.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Compostos Orgânicos/química , 2-Propanol/química , Amilose/análogos & derivados , Amilose/química , Etanol/química , Indanos/química , Metanol/química , Oxidiazóis/química , Fenilcarbamatos/química , Solventes/química , Estereoisomerismo , Estilbenos/química
2.
PLoS One ; 15(5): e0223344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365104

RESUMO

Stilbenes are a group of chemicals characterized with the presence of 1,2-diphenylethylene. Previously, our group has demonstrated that synthesized (E)-N-(2-(3, 5-dimethoxystyryl) phenyl) furan-2-carboxamide (BK3C231) possesses potential chemopreventive activity specifically inducing NAD(P)H:quinone oxidoreductase 1 (NQO1) protein expression and activity. In this study, the cytoprotective effects of BK3C231 on cellular DNA and mitochondria were investigated in normal human colon fibroblast, CCD-18Co cells. The cells were pretreated with BK3C231 prior to exposure to the carcinogen 4-nitroquinoline 1-oxide (4NQO). BK3C231 was able to inhibit 4NQO-induced cytotoxicity. Cells treated with 4NQO alone caused high level of DNA and mitochondrial damages. However, pretreatment with BK3C231 protected against these damages by reducing DNA strand breaks and micronucleus formation as well as decreasing losses of mitochondrial membrane potential (ΔΨm) and cardiolipin. Interestingly, our study has demonstrated that nitrosative stress instead of oxidative stress was involved in 4NQO-induced DNA and mitochondrial damages. Inhibition of 4NQO-induced nitrosative stress by BK3C231 was observed through a decrease in nitric oxide (NO) level and an increase in glutathione (GSH) level. These new findings elucidate the cytoprotective potential of BK3C231 in human colon fibroblast CCD-18Co cell model which warrants further investigation into its chemopreventive role.


Assuntos
4-Nitroquinolina-1-Óxido/toxicidade , Colo/efeitos dos fármacos , Citoproteção , Dano ao DNA/efeitos dos fármacos , Furanos/farmacologia , Mutagênicos/toxicidade , Estilbenos/farmacologia , Linhagem Celular , Colo/citologia , Reparo do DNA/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Furanos/química , Humanos , Mitocôndrias/efeitos dos fármacos , NAD(P)H Desidrogenase (Quinona)/metabolismo , Estilbenos/química
3.
Mol Pharmacol ; 98(1): 24-37, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32362585

RESUMO

High-dose synthetic estrogen therapy was the standard treatment of advanced breast cancer for three decades until the discovery of tamoxifen. A range of substituted triphenylethylene synthetic estrogens and diethylstilbestrol were used. It is now known that low doses of estrogens can cause apoptosis in long-term estrogen deprived (LTED) breast cancer cells resistant to antiestrogens. This action of estrogen can explain the reduced breast cancer incidence in postmenopausal women over 60 who are taking conjugated equine estrogens and the beneficial effect of low-dose estrogen treatment of patients with acquired aromatase inhibitor resistance in clinical trials. To decipher the molecular mechanism of estrogens at the estrogen receptor (ER) complex by different types of estrogens-planar [17ß-estradiol (E2)] and angular triphenylethylene (TPE) derivatives-we have synthesized a small series of compounds with either no substitutions on the TPE phenyl ring containing the antiestrogenic side chain of endoxifen or a free hydroxyl. In the first week of treatment with E2 the LTED cells undergo apoptosis completely. By contrast, the test TPE derivatives act as antiestrogens with a free para-hydroxyl on the phenyl ring that contains an antiestrogenic side chain in endoxifen. This inhibits early E2-induced apoptosis if a free hydroxyl is present. No substitution at the site occupied by the antiestrogenic side chain of endoxifen results in early apoptosis similar to planar E2 The TPE compounds recruit coregulators to the ER differentially and predictably, leading to delayed apoptosis in these cells. SIGNIFICANCE STATEMENT: In this paper we investigate the role of the structure-function relationship of a panel of synthetic triphenylethylene (TPE) derivatives and a novel mechanism of estrogen-induced cell death in breast cancer, which is now clinically relevant. Our study indicates that these TPE derivatives, depending on the positioning of the hydroxyl groups, induce various conformations of the estrogen receptor's ligand-binding domain, which in turn produces differential recruitment of coregulators and subsequently different apoptotic effects on the antiestrogen-resistant breast cancer cells.


Assuntos
Neoplasias da Mama/metabolismo , Antagonistas de Estrogênios/síntese química , Receptor alfa de Estrogênio/química , Receptor alfa de Estrogênio/metabolismo , Estilbenos/síntese química , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Estradiol/química , Estradiol/farmacologia , Antagonistas de Estrogênios/química , Antagonistas de Estrogênios/farmacologia , Feminino , Humanos , Células MCF-7 , Modelos Moleculares , Simulação de Dinâmica Molecular , Estrutura Molecular , Estilbenos/química , Estilbenos/farmacologia , Relação Estrutura-Atividade
4.
Zhongguo Zhong Yao Za Zhi ; 45(5): 1114-1119, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32237454

RESUMO

Polygonflavanol B(1), a new flavonostilbene glycoside, was isolated from the roots of Polygonum multiforum(Polygonaceae) by various column chromatography methods including macroporous resin HP-20, silica gel, Sephadex LH-20, and preparative HPLC. The structure with absolute configuration of the new compound was identified by its physicochemical properties, spectroscopic data, ECD calculation, and chemical method.


Assuntos
Fallopia multiflora/química , Flavonóis/química , Glicosídeos/química , Raízes de Plantas/química , Estilbenos/química , Flavonóis/isolamento & purificação , Glicosídeos/isolamento & purificação , Estilbenos/isolamento & purificação
5.
Chemistry ; 26(28): 6224-6233, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32030823

RESUMO

G-quadruplex nucleic acid structures have long been studied as anticancer targets whilst their potential in antiparasitic therapy has only recently been recognized and barely explored. Herein, we report the synthesis, biophysical characterization, and in vitro screening of a series of stiff-stilbene G4 binding ligands featuring different electronics, side-chain chemistries, and molecular geometries. The ligands display selectivity for G4 DNA over duplex DNA and exhibit nanomolar toxicity against Trypasanoma brucei and HeLa cancer cells whilst remaining up to two orders of magnitude less toxic to non-tumoral mammalian cell line MRC-5. Our study demonstrates that stiff-stilbenes show exciting potential as the basis of selective anticancer and antiparasitic therapies. To achieve the most efficient G4 recognition the scaffold must possess the optimal electronics, substitution pattern and correct molecular configuration.


Assuntos
Antineoplásicos/farmacologia , Antiparasitários/farmacologia , DNA/química , Neoplasias/tratamento farmacológico , Estilbenos/química , Telômero/metabolismo , Antineoplásicos/química , Antiparasitários/química , Sítios de Ligação , Dicroísmo Circular , DNA/metabolismo , Desenho de Fármacos , Quadruplex G , Humanos , Neoplasias/química , Relação Estrutura-Atividade , Telômero/química
6.
Molecules ; 25(1)2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31935877

RESUMO

Increasing studies have reported that cancer stem cells (CSCs) play critical roles in therapeutic resistance, recurrence, and metastasis of tumors, including cervical cancer. Pterostilbene, a dimethylated derivative of resveratrol, is a plant polyphenol compound with potential chemopreventive activity. However, the therapeutic effect of pterostilbene against cervical CSCs remains unclear. In this study, we compared the anticancer effects of resveratrol and pterostilbene using both HeLa cervical cancer adherent and stem-like cells. Pterostilbene more effectively inhibited the growth and clonogenic survival, as well as metastatic ability of HeLa adherent cells than those of resveratrol. Moreover, the superior inhibitory effects of pterostilbene compared to resveratrol were associated with the enhanced activation of multiple mechanisms, including cell cycle arrest at S and G2/M phases, induction of ROS-mediated caspase-dependent apoptosis, and inhibition of matrix metalloproteinase (MMP)-2/-9 expression. Notably, pterostilbene exhibited a greater inhibitory effect on the tumorsphere-forming and migration abilities of HeLa cancer stem-like cells compared to resveratrol. This greater effect was achieved through more potent inhibition of the expression levels of stemness markers, such as CD133, Oct4, Sox2, and Nanog, as well as signal transducer and activator of transcription 3 signaling. These results suggest that pterostilbene might be a potential anticancer agent targeting both cancer cells and cancer stem-like cells of cervical cancer via the superior bioavailability to resveratrol.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Resveratrol/farmacocinética , Estilbenos/administração & dosagem , Estilbenos/farmacocinética , Neoplasias do Colo do Útero/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/genética , Disponibilidade Biológica , Biomarcadores , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Feminino , Expressão Gênica , Humanos , Estrutura Molecular , Resveratrol/química , Estilbenos/química , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologia
7.
Carbohydr Polym ; 231: 115763, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888848

RESUMO

The complexation of the bioactive compound oxyresveratrol (OXY) with a polymer called cyclodextrin-based nanosponge (CD-NS) and its application was studied.A new methodology is used to calculate, an apparent inclusion complex constant (KFapp) between a ligand and CD-NSs. Moreover, the KFapp of resveratrol was also evaluated and compared. The complex of OXY with the nanosponge ß-CDI 1:4, was studied in vitro using DSC, TGA and FTIR techniques and its drug loading and release behavior were studied. An in vitro digestion showed higher protection of OXY complexed than free OXY. The bioactivity enhancing capacity of OXY was also studied against prostate (PC-3) and colon (HT-29 and HCT-116) cancer cell lines, where it showed stronger cell viability inhibition than the free drug. The findings as a whole represent a new opportunity for studying the complexation of drugs in CD-NSs and the use of oxyresveratrol as an ingredient in nutraceutical products.


Assuntos
Antineoplásicos/química , Nanoestruturas/química , Extratos Vegetais/farmacologia , Estilbenos/farmacologia , beta-Ciclodextrinas/química , Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Células HCT116 , Humanos , Masculino , Extratos Vegetais/química , Polímeros/química , Neoplasias da Próstata/tratamento farmacológico , Solubilidade , Estilbenos/química , Temperatura , beta-Ciclodextrinas/farmacologia
8.
J Agric Food Chem ; 68(6): 1555-1562, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31986026

RESUMO

Passiflora edulis Sims (passion fruit) seeds are often discarded as byproducts during juice processing. In fact, the seeds are of considerable commercial value in the food and cosmetics industry because of their rich polyphenols, especially piceatannol. In this study, high-speed countercurrent chromatography (HSCCC) was applied for the separation of stilbene polyphenols from passion fruit seeds. The n-hexane-ethyl acetate-methanol-water (1:2:1:2.8, v/v) was found to be the optimum two-phase solvent for the preparation of two major stilbenes, scirpusin B (8) and piceatannol (9) with purities of 90.2% and 94.8%, respectively. In addition, a continuous semipreparative HPLC was applied to further purify the HSCCC fractions containing minor stilbenes and obtain four new piceatannol derivatives (1-4) along with three known ones (5-7). The structures of these new compounds were determined using spectroscopic methods, including NMR, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and circular dichroism (CD). The isolated compounds were evaluated for α-glucosidase inhibitory activities in vitro. The result suggested that all of them exhibited more significant activity than acarbose, and passiflorinol B (2) had the strongest activity, with a IC50 value of 1.7 µM.


Assuntos
Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Passiflora/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Estilbenos/química , Estilbenos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Distribuição Contracorrente , Frutas/química , Sementes/química , alfa-Glucosidases/química
9.
Carbohydr Polym ; 230: 115614, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887875

RESUMO

Fluorescent bioprobs are in urgent demand to monitor important biological events in biomedicine. However, the aggregation-caused quenching character, high toxicity, water-insolubility and easy leakage property of conventional small molecular dyes hinder the development in this area. In this work, an aggregation-induced emission (AIE) bioconjugate was synthesised by labeling tetraphenylethylene (TPE) to quaternized chitosan (QCS). The TPE-QCS bioconjugate emits strong fluorescence even in solid state, and is cationic and water-soluble over a wide range of pH values. The TPE-QCS aqueous solution stained HeLa cells by dose- and time-depent manner and imaged living cells with bright fluorescence. Futhermore, the cationic bioconjugate was readily internalized by cells through endocytosis, and further aggragated to large sizes and adhered to negatively charged organelle membranes inside cells achieving fluorescent cell imaging with fluorescence enhancement and leakage-free staining. The AIE-active TPE-QCS with cationic nature, good water-solubility over a wide pH range and unique cell imaging properties could trace HeLa cells for as long as 23 passages, that was obviously superior to existing commercial cellular tracer, so has promising application prospects as ultra long-term tracer in biomedical field.


Assuntos
Quitosana/análogos & derivados , Corantes Fluorescentes/química , Nanoconjugados/química , Células 3T3 , Absorção de Radiação , Animais , Cátions/química , Endocitose , Células HeLa , Humanos , Camundongos , Polimerização , Solubilidade , Estilbenos/química , Raios Ultravioleta
10.
Eur J Med Chem ; 189: 112050, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31954879

RESUMO

A series of novel 1,4-diaryl-2-azetidinone analogues of combretastatin A-4 (CA-4) have been designed, synthesised and evaluated in vitro for antiproliferative activity, antiapoptotic activity and inhibition of tubulin polymerisation. Glucuronidation of CA-4 by uridine 5-diphosphoglucuronosyl transferase enzymes (UGTs) has been identified as a mechanism of resistance in cancer cells. Potential sites of ring B glucuronate conjugation are removed by replacing the B ring meta-hydroxy substituent of selected series of ß-lactams with alternative substituents e.g. F, Cl, Br, I, CH3. The 3-phenyl-ß-lactam 11 and 3-hydroxy-ß-lactam 46 demonstrate improved activity over CA-4 in CA-4 resistant HT-29 colon cancer cells (IC50 = 9 nM and 3 nM respectively compared with IC50 = 4.16 µM for CA-4), while retaining potency in MCF-7 breast cancer cells (IC50 = 17 nM and 22 nM respectively compared with IC50 = for 4 nM for CA-4). Compound 46 binds at the colchicine site of tubulin, and strongly inhibits tubulin assembly at micromolar concentrations comparable to CA-4. In addition, compound 46 induced mitotic arrest at low concentration in both cell lines MCF-7 and HT-29 together with downregulation of expression of antiapoptotic proteins Mcl-1, Bcl-2 and survivin in MCF-7 cells. These novel antiproliferative and antiapoptotic ß-lactams are potentially useful scaffolds in the development of tubulin-targeting agents for the treatment of breast cancers and chemoresistant colon cancers.


Assuntos
Antineoplásicos/farmacologia , beta-Lactamas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células HEK293 , Humanos , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Necrose/induzido quimicamente , Ligação Proteica , Estilbenos/química , Survivina/metabolismo , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologia , beta-Lactamas/síntese química , beta-Lactamas/metabolismo
11.
Int J Mol Sci ; 21(2)2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31936484

RESUMO

Plant polyphenols are a huge group of compounds with a wide spectrum of applications. Substances from this group have been used in polymer materials such as stabilizers, dyes, indicators, fungicides, and bactericides, especially in new generation packaging materials. The aim of this study is to obtain environmentally friendly materials based on the biodegradable aliphatic polyesters, polylactide (PLA) and polyhydroxyalkanoate (PHA), with plant functional additives, (+)-catechin and polydatin. These natural polyphenols (polydatin and (+)-catechin) have not been used so far in polymer materials (especially in biodegradable polyesters) as stabilizers, dyes, and indicators of aging. The application of polydatin and (+)-catechin as multifunctional additives for biodegradable polymers is a scientific novelty. This paper presents the following analyses of polyester materials: SEM microscopy, wide angle x-ray diffraction, mechanical properties, thermal analysis, surface free energy analysis, and determination of change of color after controlled UV exposure, thermal oxidation and weathering. Both PLA and PHA polyesters were characterized by higher resistance to oxidation and greater resistance to degradation under the influence of UV radiation. In addition, (+)-catechin was used simultaneously as a dye and an indicator of the aging time of polymeric materials. In contrast, polydatin did not dye polymers, but was a very good indicator of their lifetime, changing color under the influence of various external factors. Both polyphenols can be successfully used as natural additives for pro-ecological polyesters.


Assuntos
Materiais Biocompatíveis/química , Catequina/química , Glucosídeos/química , Poliésteres/química , Estilbenos/química , Varredura Diferencial de Calorimetria , Oxirredução , Poli-Hidroxialcanoatos/química , Polifenóis/química , Temperatura , Termogravimetria , Difração de Raios X
12.
Biomater Sci ; 8(1): 118-124, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31777865

RESUMO

On account of the biological significance of self-assembling peptides in blocking the cellular mass exchange as well as impeding the formation for actin filaments resulting in program cell death, stimuli-responsive polypeptide nanoparticles have attracted more and more attention. In this work, we successfully fabricated doxorubicin-loaded polyethylene glycol-block-peptide (FFKY)-block-tetraphenylethylene (PEG-Pep-TPE/DOX) nanoparticles, where the aggregation-induced emission luminogens (AIEgen, TPE-CHO) can become a fluorescence resonance energy transfer (FRET) pair with the entrapped antitumor drug DOX to detect the release of drugs dynamically. This is the first successful attempt to detect and quantify the change of FRET signals in A549 cells via three methods to monitor the cellular uptake of nanoprobes and intracellular drug molecule release intuitively. As we proposed here, the combination of free DOX and the self-assembling peptide could achieve the synergistic anticancer efficacy. The multifunctional PEG-Pep-TPE/DOX nanoparticles may provide a new opportunity for combination cancer therapy and real-time detection of the drug release from stimuli-responsive nanomedicine.


Assuntos
Antineoplásicos/química , Doxorrubicina/química , Transferência Ressonante de Energia de Fluorescência/métodos , Nanopartículas/química , Peptídeos/química , Polietilenoglicóis/química , Estilbenos/química , Células A549 , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Glutationa/química , Humanos , Concentração de Íons de Hidrogênio , Substâncias Luminescentes/química , Nanopartículas/toxicidade
13.
Biomater Sci ; 8(1): 325-332, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31714543

RESUMO

Although the polymeric vascular disrupting agent (poly(l-glutamic acid)-graft-methoxy poly(ethylene glycol)/combretastatin A4) nanoparticles (CA4-NPs) has great potential to inhibit cancer growth, it is still a challenge to avert tumor recurrence and metastasis after treatment. It is mainly tightly associated with hypoxia induced by CA4-NPs, which can activate many downstream genes regulating tumor growth and metastasis. Herein, to relieve a tumor hypoxia microenvironment, the mTOR inhibitor temsirolimus was employed to modulate the tumor microenvironment when treated with CA4-NPs. In vitro MTT experiments strongly verified that the combination of temsirolimus with polymeric CA4-NPs exhibited an additive toxicity to 4T1 cells. An in vivo study with the 4T1 mammary adenocarcinoma model revealed that consistent with the proposed scenario, combination therapy with CA4-NPs plus temsirolimus suppressed tumor growth significantly more strongly compared to either CA4-NPs or temsirolimus monotherapy, and the inhibition rate to 4T1 tumor with a volume of 300 mm3 was 71%. The mechanism underling combination treatment was confirmed by western blotting and immunofluorescence staining, and the results demonstrated that temsirolimus could inhibit HIF1α expression. Thus, this work provides a mechanistic rationale for the use of VDAs in combination with the mTOR inhibitor to enhance anticancer efficacy, delaying tumor recurrence and inhibiting tumor metastasis.


Assuntos
Hipóxia Celular , Polímeros/química , Sirolimo/análogos & derivados , Microambiente Tumoral/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Metástase Neoplásica , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Polietilenoglicóis/química , Ácido Poliglutâmico/química , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Estilbenos/química , Estilbenos/farmacologia , Estilbenos/uso terapêutico
14.
J Chromatogr A ; 1614: 460702, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31740032

RESUMO

A stilbene diamido-bridged bis(ß-cyclodextrin) was synthesized via the reaction between 4,4'-stilbene dicarboxylic acid and 6-deoxy-6-amino-ß-cyclodextrin. Then it was bonded onto the surface of an ordered mesoporous SBA-15 to obtain a novel bridged bis(ß-cyclodextrin)-bonded chiral stationary phase (SBCDP). The structures of the bridged bis(ß-cyclodextrin) and SBCDP were characterized by the mass spectrometry, nuclear magnetic resonance, infrared spectroscopy, elemental analysis and thermogravimetric analysis. The chromatographic performance of SBCDP was systematically evaluated by separating 23 racemic drugs and pesticides, including trimeprazine, praziquantel, flavanones, ß-blockers and triazole pesticides in the reversed-phase chromatography or the polar organic mode. The chromatographic conditions that affect the enantioselectivity or diasterioselectivity of SBCDP were investigated in detail, including the mobile phase composition, pH value and column temperature. As a result, all tested analytes were resolved on SBCDP with high resolutions (1.51∼5.15) within about 25 min, and the enantioseparation resolutions of flavanone and imazalil were up to 5.15 and 4.38, respectively. Compared with the native ß-cyclodextrin stationary phase (CDCSP), the SBCDP had a better chromatographic performance in enantioselectivity and diasterioselectivity. For example, enantiomers of trimeprazine, praziquantel, flavanone and imazalil those could not be separated by CDCSP, were separated by SBCDP with high resolutions. Unlike the small cavity (0.65 nm) of native CD, the bridging linker of the bridged bis(ß-CD) supplied a well-organized "pseudo-cavity", and combined two native CDs as an organic whole, which could synergistically encapsulate and complex some bulky analytes, making the chiral discrimination of SBCDP more precise. Moreover, we also found that SBCDP possessed high enantioselectivity and diastereoselectivity over a wide range of temperature (30∼60 °C), which made the fast analysis possible. As a new chiral separation material, SBCDP may have wider applications in analysis of chiral compounds.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Praguicidas/análise , Preparações Farmacêuticas/análise , Estilbenos/química , Concentração de Íons de Hidrogênio , Praguicidas/isolamento & purificação , Preparações Farmacêuticas/isolamento & purificação , Porosidade , Dióxido de Silício/química , Estereoisomerismo , beta-Ciclodextrinas/química
15.
J Sci Food Agric ; 100(4): 1392-1404, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31756276

RESUMO

Resveratrol, a stilbene molecule belonging to the polyphenol family, is usually extracted from a great many natural plants. The technologies of preparation and extraction methods are developing rapidly. As resveratrol has many beneficial properties, it has been widely utilized in food and medicine industry. In terms of its structure, it is susceptible to degradation and can undergo chemical changes during food processing. Different studies have therefore given more attention to various aspects of resveratrol, including anti-aging, anti-oxidant, and anti-cancer activity. This review classifies the study of resveratrol, considers plant sources, synthesis, stability, common reactions, and food applications, and provides references to boost its food and medical utilization. © 2019 Society of Chemical Industry.


Assuntos
Extratos Vegetais/química , Resveratrol/química , Estilbenos/química , Animais , Humanos , Extratos Vegetais/síntese química , Extratos Vegetais/farmacologia , Plantas/química , Resveratrol/síntese química , Resveratrol/farmacologia , Estilbenos/síntese química , Estilbenos/farmacologia
16.
Nat Prod Res ; 34(3): 323-328, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30580630

RESUMO

Chemical investigation of Dendrobium plicatile Lindl resulted in the isolation and identification of one new bibenzyl, 2-chloro-3, 4'-dihydroxy-3',5-dimethoxybibenzyl (1), as well as 15 known stilbenoids. The structures of this new compound was elucidated by extensive spectroscopic analysis, including HRESIMS, 1H and 13C NMR, DEPT, HMBC, COSY, HMQC, NOESY. Compounds 2, 3 and 5 were obtained from this genus for the first time, compounds 8, 10, 13 and 14 were obtained from this plant for the first time. In addition, the new compound exhibited potent cytotoxic activities against the human breast cancer (MDA-MB231) cell line, the hepatocellular carcinoma (HepG2) cell line and the human lung carcinoma (A549) cell line, with IC50 3.41, 3.02, 2.80 µM, respectively.


Assuntos
Dendrobium/química , Componentes Aéreos da Planta/química , Estilbenos/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Citotoxinas/isolamento & purificação , Citotoxinas/farmacologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Análise Espectral/métodos , Estilbenos/química , Estilbenos/farmacologia
17.
Anal Chim Acta ; 1094: 130-135, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31761039

RESUMO

Quantification of plasma membrane proteins (PMPs) is crucial for understanding the fundamentals of cellular signaling systems and their related diseases. In this work, a super-quadruplex scaffold was designed to regulate assembly of oligonucleotide-grafted AIEgens for detection of PMPs. The nonfluorescence oligonucleotide-grafted AIEgen (Oligo-AIEgen) was firstly synthesized by attaching the AIEgen to 3'-terminus of the oligonucleotide through click chemistry. Meanwhile, the tetramolecular hairpin-conjugated super-quadruplex (THP-G4) as cleavage element and signal enhancement scaffold composited of three elements: a substrate sequence of DNAzyme in the loop region, partial hybridization region in the stem, and six guanine nucleotides to form G-quadruplex. Once the DNAzyme was anchored on the specific PMPs through aptamer-protein recognition, the substrate sequence on the loop of THP-G4 was cleaved by DNAzyme with the aid of cofactor MnII, resulting in the conformation switch of THP-G4 to the activated G-quadruplex scaffold. The latter could assemble Oligo-AIEgens to generate aggregation-induced emission (AIE) enhancement, resulting in a simple and sensitive strategy for detection of membrane proteins. Moreover, the DNAzyme continuously cut the next THP-G4 to achieve recycling amplification. Under the optimized conditions, this AIE-based strategy exhibited good linear relationship with the logarithm of MUC1 concentration from 0.01 to 10 µg mL-1 with the limit of detection down to 4.3 ng mL-1. The G4-assembled AIEgens provides a universal platform for detecting various biomolecules and a proof-of concept for AIE biosensing.


Assuntos
Acrilonitrila/análogos & derivados , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/química , Quadruplex G , Mucina-1/análise , Estilbenos/química , Acrilonitrila/síntese química , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/genética , Linhagem Celular Tumoral , DNA Catalítico/química , DNA Catalítico/genética , Corantes Fluorescentes/síntese química , Humanos , Limite de Detecção , Mucina-1/química , Hibridização de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/genética , Estudo de Prova de Conceito , Estilbenos/síntese química
18.
J Agric Food Chem ; 68(1): 340-350, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31874034

RESUMO

Folic acid, a synthetic form of folate, is a water-soluble vitamin that is essential during periods of rapid cell division and growth. However, it decomposes upon ultraviolet irradiation to form inactive photoproducts. In this study, the protective effect and mechanisms of antioxidants, including cinnamic acids, flavonoids, catechol and its derivatives, stilbenes, p-benzoquinone and its derivatives, isoprenoids, curcumin, oleic acid, and linoleic acid, against folic acid photodecomposition were investigated by using fluorescence and absorbance spectroscopy, high-performance liquid chromatography, and antioxidant assay. It was found that antioxidants could inhibit or delay the folic acid decomposition in varying degrees, among which caffeic acid was the most effective. The increase in its remarkable antioxidant efficiency and absorbance in the UVA region during irradiation contributed to its effective protection. This finding could be useful for the protection of photolabile components in food and other uses.


Assuntos
Antioxidantes/química , Ácido Fólico/química , Benzoquinonas/química , Catecóis/química , Cinamatos/química , Flavonoides/química , Fotólise/efeitos dos fármacos , Fotólise/efeitos da radiação , Estilbenos/química , Raios Ultravioleta
19.
J Sci Food Agric ; 100(1): 401-409, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31637723

RESUMO

BACKGROUND: It is widely recognized that ambient levels of solar ultraviolet (UV) radiation strongly influence the phenolic composition of grape skins. However, it is unknown to what extent this influence is reflected in the resulting wines. RESULTS: Tempranillo grapevines were exposed or non-exposed to close-to-ambient solar UV levels using appropriate filters, and the phenolic profiles and antioxidant capacity of both grape skins and the resulting wines were analyzed. In total, 47 phenolic compounds were identified in skins and wines, including flavonols, anthocyanins, flavanols, stilbenes, and hydroxycinnamic and hydroxybenzoic acids. In UV-exposed grape skins, flavonols and anthocyanins increased, whereas flavanols and hydroxybenzoic acids showed no significant change. These characteristics were conserved in the resulting wines. However, for stilbenes, hydroxycinnamic acids and antioxidant capacity, the effect of UV on grape skins was not conserved in wines, probably as a result of changes during winemaking. In addition, color intensity, total phenols and total polyphenol index of wines elaborated from UV-exposed grapes increased (although non-significantly) compared to those made from non-UV-exposed grapes. CONCLUSION: The phenolic composition of grape skins exposed to close-to-ambient solar UV could predict, to some extent, the phenolic composition of the resulting wines, particularly regarding higher contents of flavonols and anthocyanins. Thus, manipulating the UV radiation received by grape skins could improve wine quality by positively influencing color stability and healthy properties. To our knowledge, this is the first study in which the effects of solar UV radiation on phenolic composition have been assessed from grape skins to wine. © 2019 Society of Chemical Industry.


Assuntos
Frutas/efeitos da radiação , Fenóis/química , Vitis/química , Vinho/análise , Antocianinas/química , Antioxidantes/química , Flavonóis/química , Frutas/química , Polifenóis/química , Estilbenos/química , Raios Ultravioleta , Vitis/efeitos da radiação
20.
Talanta ; 206: 120177, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514882

RESUMO

Two highly selective OFF-ON isomer fluorescent probes (1 and 2) for homo-/cysteine were designed and synthesized. The pyrene modified tetraphenylethylene derivative with AIE was used as luminescent group while maleimide was used as recognition group. These two isomer probes were found to be nearly nonfluorescent when treated with GSH. However, upon interaction with Cys or Hcy, the fluorescence was enhanced by 2000 folds in a wide pH range from 3 to 10. Experimental results and DFT calculation have demonstrated that the fluorescence OFF-ON switch of such thiol probes is resulted from the termination of the PET (photo-induced electron transfer) effect through the Michael addition reaction of maleimide unit and thiols. In addition, probe 1 and 2 exhibit excellent selectivity and sensitivity towards Cys, Hcy over GSH and other amino acids, which was confirmed by mass MS. We suggested that Michael addition reaction of these probes with GSH was prevented because of the stereo-hindrance effect. Furthermore, these two isomer probes were successfully used for imaging biothiols in living H1299 lung cancer cells.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Glutationa/química , Homocisteína/análise , Linhagem Celular Tumoral , Cisteína/química , Teoria da Densidade Funcional , Fluorescência , Corantes Fluorescentes/síntese química , Homocisteína/química , Humanos , Maleimidas/síntese química , Maleimidas/química , Microscopia de Fluorescência/métodos , Modelos Químicos , Estilbenos/síntese química , Estilbenos/química
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