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1.
Biomolecules ; 13(5)2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37238625

RESUMO

Fumonisins are frequent food contaminants. The high exposure to fumonisins can cause harmful effects in humans and animals. Fumonisin B1 (FB1) is the most typical member of this group; however, the occurrence of several other derivatives has been reported. Acylated metabolites of FB1 have also been described as possible food contaminants, and the very limited data available suggest their significantly higher toxicity compared to FB1. Furthermore, the physicochemical and toxicokinetic properties (e.g., albumin binding) of acyl-FB1 derivatives may show large differences compared to the parent mycotoxin. Therefore, we tested the interactions of FB1, N-palmitoyl-FB1 (N-pal-FB1), 5-O-palmitoyl-FB1 (5-O-pal-FB1), and fumonisin B4 (FB4) with human serum albumin as well as the toxic effects of these mycotoxins on zebrafish embryos were examined. Based on our results, the most important observations and conclusions are the following: (1) FB1 and FB4 bind to albumin with low affinity, while palmitoyl-FB1 derivatives form highly stable complexes with the protein. (2) N-pal-FB1 and 5-O-pal-FB1 likely occupy more high-affinity binding sites on albumin. (3) Among the mycotoxins tested, N-pal-FB1 showed the most toxic effects on zebrafish, followed by 5-O-pal-FB1, FB4, and FB1. (4) Our study provides the first in vivo toxicity data regarding N-pal-FB1, 5-O-pal-FB1, and FB4.


Assuntos
Fumonisinas , Micotoxinas , Animais , Humanos , Fumonisinas/toxicidade , Fumonisinas/metabolismo , Micotoxinas/toxicidade , Peixe-Zebra/metabolismo , Albumina Sérica Humana
2.
Metabolites ; 13(3)2023 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-36984886

RESUMO

Mycotoxins are toxic metabolites of molds. Chronic exposure to alternariol, zearalenone, and their metabolites may cause the development of endocrine-disrupting and carcinogenic effects. Alternariol-3-glucoside (AG) and alternariol-9-monomethylether-3-glucoside (AMG) are masked derivatives of alternariol. Furthermore, in mammals, zearalenone-14-glucuronide (Z14Glr) is one of the most dominant metabolites of zearalenone. In this study, we examined serum albumins and cyclodextrins (CDs) as potential binders of AG, AMG, and Z14Glr. The most important results/conclusions were as follows: AG and AMG formed moderately strong complexes with human, bovine, porcine, and rat albumins. Rat albumin bound Z14Glr approximately 4.5-fold stronger than human albumin. AG-albumin and Z14Glr-albumin interactions were barely influenced by the environmental pH, while the formation of AMG-albumin complexes was strongly favored by alkaline conditions. Among the mycotoxin-CD complexes examined, AMG-sugammadex interaction proved to be the most stable. CD bead polymers decreased the mycotoxin content of aqueous solutions, with moderate removal of AG and AMG, while weak extraction of Z14Glr was observed. In conclusion, rat albumin is a relatively strong binder of Z14Glr, and albumin can form highly stable complexes with AMG at pH 8.5. Therefore, albumins can be considered as affinity proteins with regard to the latter mycotoxin metabolites.

3.
Biomed Pharmacother ; 157: 114078, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36481402

RESUMO

Luteolin and naringenin are flavonoids found in various foods/beverages and present in certain dietary supplements. After a high intake of these flavonoids, their sulfate and glucuronide conjugates reach micromolar concentrations in the bloodstream. Some pharmacokinetic interactions of luteolin and naringenin have been investigated in previous studies; however, only limited data are available in regard to their metabolites. In this study, we aimed to investigate the interactions of the sulfate and glucuronic acid conjugates of luteolin and naringenin with human serum albumin, cytochrome P450 (CYP2C9, 2C19, and 3A4) enzymes, and organic anion transporting polypeptide (OATP1B1 and OATP2B1) transporters. Our main findings are as follows: (1) Sulfate conjugates formed more stable complexes with albumin than the parent flavonoids. (2) Luteolin and naringenin conjugates showed no or only weak inhibitory action on the CYP enzymes examined. (3) Certain conjugates of luteolin and naringenin are potent inhibitors of OATP1B1 and/or OATP2B1 enzymes. (4) Conjugated metabolites of luteolin and naringenin may play an important role in the pharmacokinetic interactions of these flavonoids.


Assuntos
Citocromo P-450 CYP3A , Transportadores de Ânions Orgânicos , Humanos , Citocromo P-450 CYP3A/metabolismo , Glucuronídeos , Luteolina/farmacologia , Albumina Sérica Humana/metabolismo , Sulfatos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Flavonoides/farmacologia , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP2C19/metabolismo
4.
Int J Mol Sci ; 23(22)2022 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-36430492

RESUMO

Human serum albumin (HSA) is the most abundant plasma protein in circulation. The three most important drug-binding sites on HSA are Sudlow's Site I (subdomain IIA), Sudlow's Site II (subdomain IIIA), and Heme site (subdomain IB). Heme site and Site I are allosterically coupled; therefore, their ligands may be able to allosterically modulate the binding affinity of each other. In this study, the effects of four Heme site ligands (bilirubin, biliverdin, hemin, and methyl orange) on the interaction of the Site I ligand warfarin with HSA were tested, employing fluorescence spectroscopic, ultrafiltration, and ultracentrifugation studies. Our major results/conclusions are the following. (1) Quenching studies indicated no relevant interaction, while the other fluorescent model used suggested that each Heme site ligand strongly decreases the albumin binding of warfarin. (2) Ultrafiltration and ultracentrifugation studies demonstrated the complex modulation of warfarin-HSA interaction by the different Heme site markers; for example, bilirubin strongly decreased while methyl orange considerably increased the bound fraction of warfarin. (3) Fluorescence spectroscopic studies showed misleading results in these diligand-albumin interactions. (4) Different Heme site ligands can increase or decrease the albumin binding of warfarin and the outcome can even be concentration dependent (e.g., biliverdin and hemin).


Assuntos
Biliverdina , Varfarina , Humanos , Varfarina/farmacologia , Heme/metabolismo , Hemina , Bilirrubina , Ligantes , Albumina Sérica/metabolismo
5.
Int J Mol Sci ; 23(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36430830

RESUMO

Alternaria mycotoxins, including alternariol (AOH), alternariol-9-monomethylether (AME), and their masked/modified derivatives (e.g., sulfates or glycosides), are common food contaminants. Their acute toxicity is relatively low, while chronic exposure can lead to the development of adverse health effects. Masked/modified metabolites can probably release the more toxic parent mycotoxin due to their enzymatic hydrolysis in the intestines. Previously, we demonstrated the complex formation of AOH with serum albumins and cyclodextrins; these interactions were successfully applied for the extraction of AOH from aqueous matrices (including beverages). Therefore, in this study, the interactions of AME, alternariol-3-sulfate (AS), and alternariol-9-monomethylether-3-sulfate (AMS) were investigated with albumins (human, bovine, porcine, and rat) and with cyclodextrins (sulfobutylether-ß-cyclodextrin, sugammadex, and cyclodextrin bead polymers). Our major results/conclusions are the following: (1) The stability of mycotoxin-albumin complexes showed only minor species dependent variations. (2) AS and AMS formed highly stable complexes with albumins in a wide pH range, while AME-albumin interactions preferred alkaline conditions. (3) AME formed more stable complexes with the cyclodextrins examined than AS and AMS. (4) Beta-cyclodextrin bead polymer proved to be highly suitable for the extraction of AME, AS, and AMS from aqueous solution. (5) Albumins and cyclodextrins are promising binders of the mycotoxins tested.


Assuntos
Ciclodextrinas , Micotoxinas , Animais , Bovinos , Humanos , Ratos , Ciclodextrinas/química , Micotoxinas/química , Albumina Sérica , Sulfatos , Suínos
6.
Biomolecules ; 12(8)2022 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-36009000

RESUMO

Beauvericin (BEA), cyclopiazonic acid (CPA), and sterigmatocystin (STC) are emerging mycotoxins. They appear as contaminants in food and animal feed, leading to economic losses and health risks. Human serum albumin (HSA) forms stable complexes with certain mycotoxins, including ochratoxins, alternariol, citrinin, and zearalenone. HSA binding can influence the toxicokinetics of xenobiotics, and albumin can also be considered and applied as a relatively cheap affinity protein. Therefore, we examined the potential interactions of BEA, CPA, and STC with HSA employing fluorescence spectroscopy, ultracentrifugation, ultrafiltration, and molecular modeling. Spectroscopic and ultracentrifugation studies demonstrated the formation of low-affinity BEA-HSA (Ka ≈ 103 L/mol) and moderately strong CPA-HSA and STC-HSA complexes (Ka ≈ 104 L/mol). In ultrafiltration experiments, CPA slightly displaced each site marker (warfarin, naproxen, and camptothecin) tested, while BEA and STC did not affect significantly the albumin binding of these drugs. Modeling studies suggest that CPA occupies Sudlow's site I, while STC binds to the Heme site (FA1) on HSA. Considering the interactions of CPA with the site markers, the CPA-HSA interaction may have toxicological importance.


Assuntos
Albumina Sérica Humana , Esterigmatocistina , Animais , Sítios de Ligação , Depsipeptídeos , Humanos , Indóis , Ligação Proteica , Albumina Sérica/química , Albumina Sérica Humana/química , Espectrometria de Fluorescência , Esterigmatocistina/metabolismo , Termodinâmica
7.
Biomed Pharmacother ; 151: 113136, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35594715

RESUMO

Resveratrol (RES) is a widely-known natural polyphenol which is also contained by several dietary supplements. Large doses of RES can result in high micromolar levels of its sulfate and glucuronide conjugates in the circulation, due to the high presystemic metabolism of the parent polyphenol. Pharmacokinetic interactions of RES have been extensively studied, while only limited data are available regarding its metabolites. Therefore, in the current study, we examined the interactions of resveratrol-3-sulfate (R3S), resveratrol-3-glucuronide, and dihydroresveratrol (DHR; a metabolite produced by the colon microbiota) with human serum albumin (HSA), cytochrome P450 (CYP) enzymes, and organic anion transporting polypeptides (OATP) employing in vitro models. Our results demonstrated that R3S and R3G may play a major role in the RES-induced pharmacokinetic interactions: (1) R3S can strongly displace the site I marker warfarin from HSA; (2) R3G showed similarly strong inhibitory action on CYP3A4 to RES; (3) R3S proved to be similarly strong (OATP1B1/3) or even stronger (OATP1A2 and OATP2B1) inhibitor of OATPs tested than RES, while R3G and RES showed comparable inhibitory actions on OATP2B1.


Assuntos
Sistema Enzimático do Citocromo P-450 , Transportadores de Ânions Orgânicos , Resveratrol , Albumina Sérica , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Glucuronídeos/farmacologia , Humanos , Transportadores de Ânions Orgânicos/efeitos dos fármacos , Transportadores de Ânions Orgânicos/metabolismo , Polifenóis , Resveratrol/farmacologia , Albumina Sérica/efeitos dos fármacos , Albumina Sérica/metabolismo , Albumina Sérica Humana/metabolismo , Estilbenos/farmacologia
8.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34445400

RESUMO

Alternariol (AOH) is an emerging mycotoxin produced by Alternaria molds. It occurs as a contaminant e.g., in oilseeds, cereals, grapes, and tomatoes. Chronic exposure to AOH may cause genotoxic and endocrine disruptor effects. Our recent studies demonstrated that the fluorescence signal of AOH can be strongly affected by the environmental pH as well as by the presence of serum albumin or cyclodextrins. In the current study, we aimed to characterize the most optimal circumstances regarding the highly sensitive fluorescent detection of AOH. Therefore, the further detailed investigation of the microenvironment on the fluorescence signal of the mycotoxin has been performed, including the effects of different buffers, organic solvents, detergents, and cations. Organic solvents (acetonitrile and methanol) caused only slight increase in the emission signal of AOH, while detergents (sodium dodecyl sulfate and Triton-X100) and Ca2+ induced considerably higher enhancement in the fluorescence of the mycotoxin. In addition, Mg2+ proved to be a superior fluorescence enhancer of the AOH. Spectroscopic and modeling studies suggest the formation of low-affinity AOH-Mg2+ complexes. The effect of Mg2+ was also tested in two HPLC assays: Our results show that Mg2+ can considerably increase the fluorescence signal of AOH even in a chromatographic system.


Assuntos
Alternaria/química , Lactonas/análise , Magnésio/química , Acetonitrilas/química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Lactonas/química , Metanol/química , Conformação Molecular , Estrutura Molecular , Octoxinol/química , Dodecilsulfato de Sódio/química , Espectrometria de Fluorescência
9.
Biomed Pharmacother ; 138: 111459, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33706132

RESUMO

Silymarin is a mixture of flavonolignans isolated from the fruit of milk thistle (Silybum marianum (L.) Gaertner). Milk thistle extract is the active ingredient of several medications and dietary supplements to treat liver injury/diseases. After the oral administration, flavonolignans are extensively biotransformed, resulting in the formation of sulfate and/or glucuronide metabolites. Previous studies demonstrated that silymarin components form stable complexes with serum albumin and can inhibit certain cytochrome P450 (CYP) enzymes. Nevertheless, in most of these investigations, silybin was tested; while no or only limited information is available regarding other silymarin components and metabolites. In this study, the interactions of five silymarin components (silybin A, silybin B, isosilybin A, silychristin, and 2,3-dehydrosilychristin) and their sulfate metabolites were examined with human serum albumin and CYP (2C9, 2C19, 2D6, and 3A4) enzymes. Our results demonstrate that each compound tested forms stable complexes with albumin, and certain silymarin components/metabolites can inhibit CYP enzymes. Most of the sulfate conjugates were less potent inhibitors of CYP enzymes, but 2,3-dehydrosilychristin-19-O-sulfate showed the strongest inhibitory effect on CYP3A4. Based on these observations, the simultaneous administration of high dose silymarin with medications should be carefully considered, because milk thistle flavonolignans and/or their sulfate metabolites may interfere with drug therapy.


Assuntos
Citocromo P-450 CYP2C19/metabolismo , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP3A/metabolismo , Albumina Sérica Humana/metabolismo , Silimarina/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas/fisiologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Ligação Proteica/fisiologia , Silimarina/química , Silimarina/farmacologia , Sulfatos/química , Sulfatos/metabolismo , Sulfatos/farmacologia
10.
Mycotoxin Res ; 36(4): 389-397, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32740802

RESUMO

The xenoestrogenic mycotoxin zearalenone is a Fusarium-derived food and feed contaminant. In mammals, the reduced (e.g., zearalanone, α-zearalanol, and ß-zearalanol) and conjugated (e.g., zearalenone-14-sulfate) metabolites of zearalenone are formed. Furthermore, filamentous fungi and plants are also able to convert zearalenone to conjugated derivatives, including zearalenone-14-sulfate and zearalenone-14-glucoside, respectively. Serum albumin is the dominant plasma protein in the circulation; it interacts with certain mycotoxins, affecting their toxicokinetics. In a previous investigation, we demonstrated the remarkable species differences regarding the albumin binding of zearalenone and zearalenols. In the current study, the interactions of zearalanone, α-zearalanol, ß-zearalanol, zearalenone-14-sulfate, and zearalenone-14-glucoside with human, bovine, porcine, and rat serum albumins were examined, employing fluorescence spectroscopy and affinity chromatography. Zearalanone, zearalanols, and zearalenone-14-sulfate form stable complexes with albumins tested (K = 9.3 × 103 to 8.5 × 105 L/mol), while the albumin binding of zearalenone-14-glucoside seems to be weak. Zearalenone-14-sulfate formed the most stable complexes with albumins examined. Considerable species differences were observed in the albumin binding of zearalenone metabolites, which may have a role in the interspecies differences regarding the toxicity of zearalenone.


Assuntos
Glucosídeos/metabolismo , Micotoxinas/metabolismo , Albumina Sérica/metabolismo , Zearalenona/análogos & derivados , Zearalenona/metabolismo , Ração Animal/análise , Animais , Bovinos , Cromatografia de Afinidade , Fusarium/metabolismo , Glucosídeos/análise , Humanos , Micotoxinas/análise , Ligação Proteica , Ratos , Espectrometria de Fluorescência , Suínos , Zearalenona/análise , Zearalenona/classificação
11.
Int J Mol Sci ; 21(12)2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32570928

RESUMO

Formation of inclusion complexes involving a cavitand derivative (as host) and an antimetabolite drug, methotrexate (as guest) was investigated by photoluminescence measurements in dimethyl sulfoxide solvent. Molecular modeling performed in gas phase reflects that, due to the structural reasons, the cavitand can include the methotrexate in two forms: either by its opened structure with free androsta-4-en-3-one-17α-ethinyl arms or by the closed form when all the androsta-4-en-3-one-17α-ethinyl arms play role in the complex formation. Experiments reflect enthalpy driven complex formation in higher temperature range while at lower temperature the complexes are stabilized by the entropy gain.


Assuntos
Antimetabólitos/química , Metotrexato/química , Resorcinóis/química , Dimetil Sulfóxido/química , Estabilidade de Medicamentos , Entropia , Éteres Cíclicos/química , Modelos Moleculares , Estrutura Molecular , Solventes/química , Termodinâmica
12.
Toxins (Basel) ; 12(6)2020 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-32545742

RESUMO

Ochratoxins, patulin, deoxynivalenol, and T-2 toxin are mycotoxins, and common contaminants in food and drinks. Human serum albumin (HSA) forms complexes with certain mycotoxins. Since HSA can affect the toxicokinetics of bound ligand molecules, the potential interactions of ochratoxin B (OTB), ochratoxin C (OTC), patulin, deoxynivalenol, and T-2 toxin with HSA were examined, employing spectroscopic (fluorescence, UV, and circular dichroism) and ultrafiltration techniques. Furthermore, the influence of albumin on the cytotoxicity of these xenobiotics was also evaluated in cell experiments. Fluorescence studies showed the formation of highly stable OTB-HSA and OTC-HSA complexes. Furthermore, fluorescence quenching and circular dichroism measurements suggest weak or no interaction of patulin, deoxynivalenol, and T-2 toxin with HSA. In ultrafiltration studies, OTB and OTC strongly displaced the Sudlow's site I ligand warfarin, while other mycotoxins tested did not affect either the albumin binding of warfarin or naproxen. The presence of HSA significantly decreased or even abolished the OTB- and OTC-induced cytotoxicity in cell experiments; however, the toxic impacts of patulin, deoxynivalenol, and T-2 toxin were not affected by HSA. In summary, the complex formation of OTB and OTC with albumin is relevant, whereas the interactions of patulin, deoxynivalenol, and T-2 toxin with HSA may have low toxicological importance.


Assuntos
Ocratoxinas/metabolismo , Patulina/metabolismo , Albumina Sérica Humana/metabolismo , Toxina T-2/metabolismo , Tricotecenos/metabolismo , Sítios de Ligação , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Ocratoxinas/toxicidade , Patulina/toxicidade , Ligação Proteica , Toxina T-2/toxicidade , Tricotecenos/toxicidade
13.
Molecules ; 25(11)2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32471230

RESUMO

The sulfamethazine drug interaction with carbon nanotubes was investigated with the aim of improving the adsorption capacity of the adsorptive materials. Experiments were performed to clarify how the molecular environment affects the adsorption process. Single-walled carbon nanotubes have a higher removal efficiency of sulfamethazine than pristine or functionalized multi-walled carbon nanotubes. Although the presence of cyclodextrin molecules improves the solubility of sulfamethazine, it reduces the adsorption capacity of the carbon nanotube towards the sulfamethazine drug and, therefore, inhibits the removal of these antibiotic pollutants from waters by carbon nanotubes.


Assuntos
Nanotubos de Carbono/química , Sulfametazina/química , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Estrutura Molecular , beta-Ciclodextrinas/química
14.
Molecules ; 25(8)2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32326176

RESUMO

Interaction of 4-quinazolinone with tetrakis (3,5-dicarboxylatophenoxy)-cavitand derivative has been studied in methanol and dimethylformamide media using fluorescence spectroscopy and molecular modeling methods. Results show temperature dependent complex formation: either the entropy gain or the high enthalpy changes are responsible for the formation of stable complexes in two separated temperature regions. However, different thermodynamic parameters are associated to different conformations of the complexes: while the high entropy gain associated to the formation of deeply included guest in methanol, the high entropy gain is associated with the formation of weakly included guest in dimethylformamide solvent. This finding highlights the importance of dynamic properties of the species interacted in different solvents.


Assuntos
Éteres Cíclicos/química , Quinazolinonas/química , Resorcinóis/química , Solventes/química , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Análise Espectral , Temperatura , Termodinâmica
15.
Biomolecules ; 10(3)2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32155912

RESUMO

Flavonoids are abundant polyphenols in nature. They are extensively biotransformed in enterocytes and hepatocytes, where conjugated (methyl, sulfate, and glucuronide) metabolites are formed. However, bacterial microflora in the human intestines also metabolize flavonoids, resulting in the production of smaller phenolic fragments (e.g., hydroxybenzoic, hydroxyacetic and hydroxycinnamic acids, and hydroxybenzenes). Despite the fact that several colonic metabolites appear in the circulation at high concentrations, we have only limited information regarding their pharmacodynamic effects and pharmacokinetic interactions. Therefore, in this in vitro study, we investigated the interactions of 24 microbial flavonoid metabolites with human serum albumin and cytochrome P450 (CYP2C9, 2C19, and 3A4) enzymes. Our results demonstrated that some metabolites (e.g., 2,4-dihydroxyacetophenone, pyrogallol, O-desmethylangolensin, and 2-hydroxy-4-methoxybenzoic acid) form stable complexes with albumin. However, the compounds tested did not considerably displace Site I and II marker drugs from albumin. All CYP isoforms examined were significantly inhibited by O-desmethylangolensin; nevertheless, only its effect on CYP2C9 seems to be relevant. Furthermore, resorcinol and phloroglucinol showed strong inhibitory effects on CYP3A4. Our results demonstrate that, besides flavonoid aglycones and their conjugated derivatives, some colonic metabolites are also able to interact with proteins involved in the pharmacokinetics of drugs.


Assuntos
Sistema Enzimático do Citocromo P-450 , Eritrócitos/enzimologia , Flavonoides , Hepatócitos/enzimologia , Albumina Sérica Humana , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/metabolismo , Flavonoides/química , Flavonoides/metabolismo , Humanos , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismo
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 225: 117475, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472423

RESUMO

Sulfonamides are preventive and therapeutic agents for certain infections caused by gram-positive and gram-negative microorganisms. In this work the interactions of sulfamethazine, a representative of sulfonamide antibiotics, with two ß-cyclodextrin derivatives were investigated at different pH. Results show formation of stable sulfamethazine - ß-cyclodextrin complexes and reflect importance of the competition of the hydrogen bonding and electrostatic interactions. The complex geometry formed is affected by the orientation of the pH-dependent dipole moment of sulfamethazine molecule and prolonged prior the sulfamethazine molecule enters into the ß-cyclodextrin's cavity. Functionalization of the ß-cyclodextrin molecule doesn't affect considerably the complex stabilities, therefore the native ß-cyclodextrin molecule looks the simplest and most effective inclusion host to design selective and sensitive tool for sulfamethazine sensing.

17.
Molecules ; 24(24)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847074

RESUMO

Sulfamethazine is a representative member of the sulfonamide antibiotic drugs; it is still used in human and veterinary therapy. The protonation state of this drug affects its aqueous solubility, which can be controlled by its inclusion complexes with native or chemically-modified cyclodextrins. In this work, the temperature-dependent (298-313 K) interaction of sulfamethazine with native and randomly methylated ß-cyclodextrins have been investigated at acidic and neutral pH. Surprisingly, the interaction between the neutral and anionic forms of the guest molecule and cyclodextrins with electron rich cavity are thermodynamically more favorable compared to the cationic guest. This property probably due to the enhanced formation of zwitterionic form of sulfamethazine in the hydrophobic cavities of cyclodextrins. Spectroscopic measurements and molecular modeling studies indicated the possible driving forces (hydrophobic interaction, hydrogen bonding, and electrostatic interaction) of the complex formation, and highlighted the importance of the reorganization of the solvent molecules during the entering of the guest molecule into the host's cavity.


Assuntos
Anti-Infecciosos/química , Sulfametazina/química , beta-Ciclodextrinas/química , Interações Medicamentosas , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Solubilidade , Termodinâmica
18.
Biomolecules ; 9(11)2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31731555

RESUMO

7,8-dihydroxyflavone (DHF) is a flavone aglycone which has beneficial effects in several central nervous system diseases. Most of the pharmacokinetic properties of DHF have been characterized, while only limited information is available regarding its interactions with serum albumin and biotransformation enzymes. In this study, the interactions of DHF with albumin was examined employing fluorescence spectroscopy and ultrafiltration. Furthermore, the inhibitory effects of DHF on cytochrome P450 (CYP2C9, CYP2C19, and CYP3A4) and xanthine oxidase (XO) enzymes were also tested using in vitro models. Our results demonstrate that DHF forms a stable complex with albumin (K = 4.9 × 105 L/mol) and that it is able to displace both Site I and Site II ligands. Moreover, DHF proved to be a potent inhibitor of each enzyme tested, showing similar or slightly weaker effects than the positive controls used. Considering the above-listed observations, the coadministration of DHF with drugs may interfere with the drug therapy due to the development of pharmacokinetic interactions.


Assuntos
Citocromo P-450 CYP2C19/química , Citocromo P-450 CYP2C9/química , Citocromo P-450 CYP3A/química , Flavonas/química , Albumina Sérica Humana/química , Xantina Oxidase/química , Biotransformação
19.
Biomolecules ; 9(9)2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31480370

RESUMO

Alternariol is an Alternaria mycotoxin that appears in fruits, tomatoes, oilseeds, and corresponding products. Chronic exposure to it can induce carcinogenic and xenoestrogenic effects. Cyclodextrins (CDs) are ring-shaped molecules built up by glucose units, which form host-guest type complexes with some mycotoxins. Furthermore, insoluble CD polymers seem suitable for the extraction/removal of mycotoxins from aqueous solutions. In this study, the interactions of alternariol with ß- and γ-CDs were tested by employing fluorescence spectroscopic and modeling studies. Moreover, the removal of alternariol from aqueous solutions by insoluble ß-CD bead polymer (BBP) was examined. Our major observations/conclusions are the following: (1) CDs strongly increased the fluorescence of alternariol, the strongest enhancement was induced by the native γ-CD at pH 7.4. (2) Alternariol formed the most stable complexes with the native γ-CD (logK = 3.2) and the quaternary ammonium derivatives (logK = 3.4-3.6) at acidic/physiological pH and at pH 10.0, respectively. (3) BBP effectively removed alternariol from aqueous solution. (4) The alternariol-binding ability of ß-CD polymers was significantly higher than was expected based on their ß-CD content. (5) CD technology seems a promising tool to improve the fluorescence detection of alternariol and/or to develop new mycotoxin binders to decrease alternariol exposure.


Assuntos
Lactonas/química , Micotoxinas/química , beta-Ciclodextrinas/química , Celulose/química , Ciclodextrinas/química , Polímeros/química , Espectrometria de Fluorescência
20.
Biomolecules ; 9(8)2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31405003

RESUMO

Zearalenone (ZEN) is a Fusarium-derived xenoestrogenic mycotoxin. In plants, zearalenone-14-O-ß-d-glucoside (Z14G) is the major conjugated metabolite of ZEN, and is a masked mycotoxin. Masked mycotoxins are plant-modified derivatives, which are not routinely screened in food and feed samples. Cyclodextrins (CDs) are cyclic oligosaccharides built up from D-glucopyranose units. CDs can form stable host-guest type complexes with lipophilic molecules (e.g., with some mycotoxins). In this study, the interaction of Z14G with native and chemically modified ß- and γ-CDs was examined employing fluorescence spectroscopy and molecular modeling. Furthermore, the removal of Z14G from aqueous solution by insoluble ß-CD bead polymer (BBP) was also tested. Our results demonstrate that Z14G forms the most stable complexes with γ-CDs under acidic and neutral conditions (K ≈ 103 L/mol). Among the CDs tested, randomly methylated γ-CD induced the highest increase in the fluorescence of Z14G (7.1-fold) and formed the most stable complexes with the mycotoxin (K = 2 × 103 L/mol). Furthermore, BBP considerably reduced the Z14G content of aqueous solution. Based on these observations, CD technology seems a promising tool to improve the fluorescence analytical detection of Z14G and to discover new mycotoxin binders which can also remove masked mycotoxins (e.g., Z14G).


Assuntos
Ciclodextrinas/química , Glucosídeos/química , Micotoxinas/química , Polímeros/química , Zearalenona/análogos & derivados , Estrutura Molecular , Zearalenona/química
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