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1.
J Microbiol Methods ; 222: 106954, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38754480

RESUMO

Bacterial meningitis is an acute infection which requires rapid diagnosis and treatment due to the high mortality and serious consequences of the disease. The purpose of this study was to design a homemade multiplex PCR and a novel fluorescence biosensor on chip (FBC) to detect three important agents of meningitis including Streptococcus pneumoniae (S. pneumoniae), Neisseria meningitidis (N. meningitidis), and Haemophilus influenzae (H. influenzae). The homemade multiplex PCR can diagnose three bacterial species simultaneously. Fabrication of FBC was carried out based on the deposition of lead nanoparticles on a quartz slide using the thermal evaporation method. Then, the SH-Cap Probe/Target ssDNA /FAM-Rep probe was loaded on lead film. The evaluation of the fluorescence reaction when the probes bind to the target ssDNA was assessed by a Cytation 5 Cell Imaging Multimode Reader Bio-Tek. The limit of detections (LOD) in homemade PCR and FBC to identify S. pneumoniae were 119 × 102 CFU/mL (0.27 ng/µL) and 380 CFU/mL (9 pg/µL), respectively. The LODs of homemade PCR and FBC for detection of N. meningitidis were 4.49 CFU/mL (1.1 pg/µL) and 13 × 103 CFU/mL (30 pg/µL), respectively. Our results confirmed the LODs of homemade PCR and FBC in detection of H. influenzae were 15.1 CFU/mL (30 fg/µL) and 41 × 102 CFU/mL (90 pg/ µL), respectively. Both techniques had appropriate sensitivity and specificity in detection of S. pneumoniae, N. meningitidis and H. influenzae.

2.
Phytother Res ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561995

RESUMO

The present systematic review and dose-response meta-analysis was conducted to synthesize existing data from randomized clinical trials (RCTs) concerning the impact of citrus flavonoids supplementation (CFS) on endothelial function. Relevant RCTs were identified through comprehensive searches of the PubMed, ISI Web of Science, and Scopus databases up to May 30, 2023. Weighted mean differences and their corresponding 95% confidence intervals (CI) were pooled utilizing a random-effects model. A total of eight eligible RCTs, comprising 596 participants, were included in the analysis. The pooled data demonstrated a statistically significant augmentation in flow-mediated vasodilation (FMD) (2.75%; 95% CI: 1.29, 4.20; I2 = 87.3%; p < 0.001) associated with CFS compared to the placebo group. Furthermore, the linear dose-response analysis indicated that each increment of 200 mg/d in CFS led to an increase of 1.09% in FMD (95% CI: 0.70, 1.48; I2 = 94.5%; p < 0.001). The findings from the nonlinear dose-response analysis also revealed a linear relationship between CFS and FMD (Pnon-linearity = 0.903, Pdose-response <0.001). Our findings suggest that CFS enhances endothelial function. However, more extensive RTCs encompassing longer intervention durations and different populations are warranted to establish more precise conclusions.

3.
J Biomol Struct Dyn ; : 1-15, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37878050

RESUMO

The aggregation of tau protein in the form of paired helical filament (PHF) leads to the breakdown of microtubule structure and the development of neurodegenerative disorders, such as Alzheimer's disease. Therefore, inhibiting tau protein aggregation is a potential strategy for preventing the progression of these disorders. In this study, sulfamethoxazole (SMZ), an antibiotic that easily crosses the blood-brain barrier and interacts with tau protein, was tested for its ability to inhibit tau aggregation in vitro. Various multi-spectroscopic techniques including XRD, LDH cytotoxicity colorimetric assay, and microscopic imaging were employed. The results showed that SMZ effectively interacts with tau protein through hydrogen and van der Waals interactions. It also effectively inhibited tau protein aggregation in vitro and significantly reduced toxicity in the SH-SY5Y neuroblastoma cell line. Molecular docking and MD simulation results suggested that SMZ may reduce tau protein aggregation by interacting with the PHF6 motif. Overall, these findings indicate that SMZ has therapeutic potential as a tau protein aggregation inhibitor, at least under in vitro conditions. These findings suggest that SMZ has potential as a treatment for neurodegenerative disorders involving tau protein aggregation. However, further research is needed to confirm these results and assess the effectiveness of SMZ in animal models and clinical trials.Communicated by Ramaswamy H. Sarma.

5.
Bioorg Chem ; 139: 106681, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37385105

RESUMO

The prevalence of hyperlipidemia has increased dramatically worldwide. It is a major public health threat, characterized by the presence of an abnormal lipid profile, primarily with elevated serum total cholesterol (TC), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) levels, and reduced high-density lipoprotein (HDL) level. Genetic factors, dietary and lifestyle habits play important roles in hyperlipidemia. It can increase the risk of chronic metabolic disorders, such as obesity, cardiovascular disease, and type II diabetes. The main objective of the present study was to evaluate the effect of urazine derivatives on serum triglyceride, cholesterol, LDL, HDL, and nitric oxide (NO) levels in high-fat diet (HFD)-induced hyperlipidemic rats. Synthetic compounds were prepared and confirmed by spectroscopic methods. Then, 88 male Sprague-Dawley rats were divided into 11 groups: control, HFD-treated group, HFD plus atorvastatin-treated group, and HFD plus 8 synthetic compounds-treated groups. The body weight, triglyceride, cholesterol, LDL, HDL, and NO levels were measured. The data with p < 0.05 were considered significant. The results indicated that HFD significantly increased cholesterol, triglyceride, and LDL levels and decreased NO concentration and HDL level compared to the control group (p < 0.05). However, HFD plus urazine derivatives significantly decreased NO, cholesterol, and triglyceride levels and increased HDL levels compared to the HFD-treated group (p < 0.05). Urazine derivatives may improve liver dysfunction in HFD-induced hyperlipidemic rats by modulation of detoxification enzymes and their anti-oxidant effects and also blood lipid profile.


Assuntos
Diabetes Mellitus Tipo 2 , Hiperlipidemias , Ratos , Masculino , Animais , Ratos Sprague-Dawley , LDL-Colesterol , Hiperlipidemias/tratamento farmacológico , Hiperlipidemias/metabolismo , Lipídeos , Triglicerídeos , Colesterol
6.
Toxicon ; 225: 107066, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36841361

RESUMO

In this work, a novel electrochemical biosensor was fabricated based on modification of a glassy carbon electrode (GCE) with nafion-DNA/gold nanoparticles/poly-ethylenedioxy pyrrole/multi-walled carbon nanotubes-ionic liquid (NF-DNA/Au NPs/PEDOP/MWCNTs-IL/GCE) with the aim of amperometric detection of the DNA damage induced by thiram (TH). By incubation of the biosensor with the TH, the TH was intercalated within DNA, and the exposed DNA released negative charges at the surface of the biosensor which repelled the probe molecules and caused the amperometric response of the biosensor to be decreased. Protective effects of extra virgin olive oil (EVOO) on the DNA damage induced by the TH were investigated by recording amperometric responses of the biosensor in the presence of EVOO, and the results confirmed that the response of the biosensor didn't change to confirm the protective effects of the EVOO on preventing the DNA damage induced by the TH. A novel and sensitive electroanalytical method was developed for determination of the TH in two linear ranges including 1-6 pM and 7-10 pM based on amperometric detection of the DNA damage induced by the TH which gave a LOD of 0.31 pM. The developed methodology in this work was successful in detection of the DNA damage induced by TH, detection of protective effects of EVOO on preventing DNA damage and determination of the TH in real matrices.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Nanotubos de Carbono , Tiram , Azeite de Oliva/química , Nanopartículas Metálicas/química , Ouro/química , Nanotubos de Carbono/química , DNA/química , Dano ao DNA , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos
7.
Steroids ; 189: 109138, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36379297

RESUMO

Recently, our research group have focused on an interesting project in which a novel dual template molecularly imprinted (DTMIP) biosensor was fabricated and assisted by second-order differential pulse voltammetric (DPV) data for simultaneous determination of nandrolone decanoate (ND) and testosterone decanoate (TS). An indium tin oxide (ITO) was modified with multiwalled carbon nanotubes-graphene-ionic liquid (MWCNT-Gr-IL) and then, the fullerene C60 was casted onto the surface of MWCNT-Gr-IL/ITO and electrochemically reduced. Finally, DTMIPs were electrosynthesized by electropolymerization of 4-aminobenzoic acid (ABA) as monomer with ND and TS as template molecules to obtain the final structure of the biosensor (DTMIP/C60/MWCNT-Gr-IL/ITO). Structure of the biosensor was electrochemically and microscopically characterized. The ND and TS generated two severely overlapped DPVs at the surface of the biosensor which forced us to assist the biosensor with three-way calibration by second-order DPV data to simultaneous determine them. Two second-order algorithms including multivariate curve resolution alternating least squares (MCR-ALS) and parallel factor analysis2 (PARAFAC2) were used to build second-order calibration models and evaluation of their performance in the analysis of synthetic samples showed more superiority of the MCR-ALS than PARAFC2 which motivated us to select PARAFC2 for the analysis of urine samples as real cases. Application of the biosensor assisted by PARAFC2 for the analysis of urine samples towards simultaneous determination of ND and TS was successful.


Assuntos
Técnicas Biossensoriais , Nandrolona , Nanotubos de Carbono , Esteróides Androgênicos Anabolizantes , Nanotubos de Carbono/química , Calibragem , Testosterona , Decanoato de Nandrolona
8.
Steroids ; 190: 109159, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36566822

RESUMO

This project was performed with the aims of increasing the sensitivity of differential pulse voltammetry (DPV) which itself is a sensitive electroanalytical technique, and also to compare the area under peak (univariate calibration), height of peak (univariate calibration) and whole of vector (multivariate calibration) for calibration purposes. These topics were investigated by fabrication of a novel electrochemical biosensor for determination of cholesterol (CHO). The procedure used in this project was based on the synthesis of molecularly imprinted polymers (MIPs) to the preconcentration of CHO and its biosensing by a rotating glassy carbon electrode (GCE) modified by co-immobilization of cholesterol oxidase (CO), cholesterol esterase (CE) and horseradish peroxidase (HP) onto multiwalled carbon nanotubes-ionic liquid (COCEHP/MWCNTs-IL/GCE). The results showed that the hydrodynamic DPV (HYDPV) was much more sensitive than DPV and using the area under peak for univariate calibration purposes was more suitable than height of peak. Adsorption at the electrode surface is an important trouble which affects the height and position of voltammetric peaks, but the area under peak is not affected by adsorption therefore, it can be more suitable for univariate calibration purposes. The biosensor response was also calibrated by chronoamperometry and the results confirmed that the HYDPV was more sensitive than chronoamperometry. The next attempt was based on recording the biosensor responses based on second-order HYDPV data and modeling of them (whole of vectors) by three-way calibration methods which showed the best performance among the tested methods for determination of CHO. The biosensor response was long-term stable, repeatable and reproducible which was successfully applied to the analysis of serum sample towards determination of CHO whose results were comparable with a reference method.


Assuntos
Técnicas Biossensoriais , Nanotubos de Carbono , Limite de Detecção , Quimiometria , Técnicas Eletroquímicas/métodos , Colesterol/análise , Técnicas Biossensoriais/métodos
9.
Int J Biol Macromol ; 219: 650-662, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-35952814

RESUMO

In this work, a novel electrochemical biosensor assisted by multivariate calibration methods was developed for simultaneous estimation of rates of DNA damage induced by doxorubicin (DX), daunorubicin (DR) and idarubicin (ID), and also to simultaneous determination of the drugs. A glassy carbon electrode was efficiently modified and used as the biosensing platform. Binding and interactions of DX, DR and ID with DNA were modeled by molecular docking methods, and theoretical information was completed by experimental results. The methylene blue was able to intercalate within the DNA structure and by incubation of the biosensor with DX or DR or ID, the methylene blue was replaced by drug and therefore, the voltammetric signal of the biosensor was changed due to the exposed DNA and repelling the electrochemical probe molecules carrying negative charge. The DNA damage induced by each drug was individually monitored by differential pulse voltammetry and then, rates of DNA damage were calibrated and validated by mixture design and multivariate calibration methods. The developed multivariate calibration model constructed based on vectorization of the data was able to simultaneous detection of the rates of DNA damage induced by all the three drugs. The change in the biosensor response in the presence of the drugs was also modeled by multivariate calibration methods to simultaneous determination of the drugs.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Técnicas Biossensoriais/métodos , Calibragem , Carbono/química , Quimiometria , DNA/química , Dano ao DNA , Doxorrubicina , Técnicas Eletroquímicas/métodos , Eletrodos , Idarubicina , Azul de Metileno/química , Simulação de Acoplamento Molecular
10.
Toxicol Rep ; 9: 647-655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399215

RESUMO

In this work, we did our best to develop a novel and interesting analytical method based on coupling of spectrofluorimetry with first-order multivariate calibration techniques for simultaneous determination of lead (Pd), zinc (Zn) and cadmium (Cd) in HeLa cells. To achieve this goal, quenching of the emission of graphene (GR) was individually investigated in the presence of Pb, Zn and Cd and then, according to the linear ranges obtained from individual calibration graphs, a multivariate calibration model was developed based on modeling of the quenching of the emission of GR in the presence of the mixtures of Pb, Zn and Cd. First-order multivariate calibration models were constructed by partial least squares (PLS), principal component regression (PCR), orthogonal signal correction-PLS (OSC-PLS), continuum power regression (CPR), robust continuum regression (RCR) and partial robust M-regression (PRM) and their performances were evaluated and statistically compared. Finally, the OSC-PLS was chosen as the best model with the best practical performance for analytical purposes.

11.
Bioinorg Chem Appl ; 2021: 7019130, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34721559

RESUMO

Background. Wound healing is a complex process of replacing devitalized cellular structures and tissues with healthy cells and tissue. Nanotechnology has been increasingly proposed as a novel platform to treat wounds and skin regeneration. The aim of this study was to evaluate the antibacterial, antioxidant, cytotoxic, and cutaneous wound healing activities of phytosynthesized Au NPs using Abelmoschus esculentus (okra) and synthesized Au NPs by using the citrate synthesis method. The Ok Au NPs were characterized using various techniques like UV-Vis absorption spectroscopy, FTIR, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Cutaneous wounds were created on 30 rats and randomized into three groups: untreated and two groups treated with Ch Au NPs and Ok Au NPs. The treatment was carried out daily for 12 days. A peak characterized the Ok Au NPs at 538 nm in the UV-Vis spectrum. Based on the results of FTIR spectroscopy, various functional oxygenated groups such as hydroxyl, carboxyl, and nitrogenous groups were observed. XRD confirmed the crystalline nature of the nanoparticles. TEM images of Ok Au NPs showed a spherical shape and size range of 75 nm. DPPH test showed similar antioxidant potentials for Au NPs. The Au NPs showed cell viability in a dose-dependent manner, and this technique was found to be nontoxic. Agar well diffusion, which is the method to determine antibacterial characteristics of Au NPs, showed a significant beneficial effect against a variety of bacterial species. In addition, histopathological results showed that Au NPs could accelerate wound closure. Therefore, Au NPs could be suitable for wound healing applications.

12.
Anal Biochem ; 630: 114339, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34411552

RESUMO

This article reports results of one of our projects related to the investigation of interactions of miglitol (MIG) with normal human serum albumin (HSA) and glycated HSA (GHSA) with the help of recording spectroscopic and electrochemical data. The experimental data were analyzed by conventional and chemometric methods to extract useful information for comprehensive justifications of the interactions of the MIG with HSA and GHSA. Hard- and soft-modeling chemometric methods were used to extract quantitative and qualitative information. Then, molecular docking techniques were used to further investigation of the binding of the MIG with HSA and GHSA and the extracted results were compatible with those obtained by experimental methods. Finally, according to the binding of the BV with HSA and GHSA, second-order differential pulse voltammetric data were recorded and calibrated with three-way calibration methods for exploiting second-order advantage for determination of the GHSA in the presence of the HSA to develop a novel chemometrics assisted-electroanalytical method for diagnostic and monitoring of diabetic.


Assuntos
1-Desoxinojirimicina/análogos & derivados , Técnicas Eletroquímicas , Simulação de Acoplamento Molecular , Albumina Sérica Humana/química , 1-Desoxinojirimicina/química , Sítios de Ligação , Humanos , Software , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
13.
Int J Biol Macromol ; 181: 478-493, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33798569

RESUMO

Chemometrics is chemical discipline in which mathematical and statistical methods are coupled with chemical data to extract useful information which cannot be extracted by the use of conventional methods. When experimental techniques are assisted by chemometric methods, very interesting studies will be performed which enable us to obtain valuable information about the system under our study. Chemico-biological interactions are very useful studies which are performed to obtain information about binding of small molecules with biological macromolecules. Recently, these studies have been assisted by chemometric methods to perform advanced studies which can help us to have a deep insight to them. Literature survey showed us that multivariate analysis of the chemico-biological interactions is becoming popular and nowadays, chemometricians are using multivariate chemometric methods for resolving chemico-biological interactions. This article focuses on the works published in the literature to provide a background for those who are interested to work in this field and finally, the results will be discussed and concluded.


Assuntos
Substâncias Macromoleculares/química , Bibliotecas de Moléculas Pequenas/química , Eletroquímica , Substâncias Macromoleculares/metabolismo , Modelos Moleculares , Publicações , Bibliotecas de Moléculas Pequenas/metabolismo
14.
Protein Expr Purif ; 182: 105858, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33639278

RESUMO

Tau protein (Tau) is a proline-rich protein and in this work, we have developed a very interesting strategy based on combination of electrochemistry with chemometric methods to investigate proline cis/trans isomeration effect on the Tau aggregation. To achieve this goal, the proline residues at RTPPK motif have been replaced by alanine to generate RTPAK, RTAPK and RTAAK mutants of the Tau. Then, cyclic voltammetric (CV) responses of the Tau and RTPAK, RTAPK and RTAAK as its mutants in the presence of heparin (HEP) as an anionic inducing agent which could trigger aggregation of the Tau were recorded at physiological conditions every hour during 12 h. Therefore, 48 data sets of titrations were obtained which were handled by chemometric methods to extract useful information about aggregation of the Tau. The data were hard-modeled by EQUISPEC, SQUAD, REACTLAB and SPECFIT to extract useful quantitative information. Our results confirmed that the strength of the binding of the HEP with proteins was obeyed from Tau > RTPAK ~ RTAPK > RTAAK which confirmed that the aggregation of the proteins was obeyed from this order as well. Therefore, aggregation of the Tau is decreased by transforming Cis isomer to Trans even in the presence of an anionic inducing agent such as HEP which may have value for the treatment of Alzheimer's disease.


Assuntos
Modelos Químicos , Agregados Proteicos , Proteínas tau/química , Técnicas Eletroquímicas , Humanos , Prolina/química
15.
Chem Phys Lipids ; 229: 104895, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32165169

RESUMO

In this work, a novel molecularly imprinted electrochemical sensor (MIES) has been fabricated based on electropolymerization of a molecularly imprinted polymer (MIP) onto a glassy carbon electrode (GCE) modified with gold-palladium alloy nanoparticles (AuPd NPs)/polydopamine film (PDA)/multiwalled carbon nanotubes-chitosan-ionic liquid (MWCNTs-CS-IL) for voltammetric and impedimetric determination of cholestanol (CHO). Modifications applied to the bare GCE formed an excellent biocompatible composite film which was able to selectively detect CHO molecules. Modifications applied to the bare GCE were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (SEM). Under optimal experimental conditions, the sensor was able to detect CHO in the range of 0.1-60 pM and 1-50 pM by EIS and DPV, respectively. Moreover, the sensor showed high sensitivity, selectivity, repeatability, reproducibility, low interference and good stability towards CHO determination. Our records confirmed that the sensor was successfully able to the analysis real samples for determination of CHO.


Assuntos
Colestanol/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Impressão Molecular , Técnicas Biossensoriais , Limite de Detecção
16.
RSC Adv ; 10(24): 14422-14430, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35498492

RESUMO

In this work, a novel and very interesting analytical methodology based on coupling of digital image processing and three-way calibration has been developed for determination of nitrite in food samples. Nitrite in contact with Griess reagent is able to produce a red-colored azo dye whose color intensity is correlated with nitrite concentration and here, a piece of Whatman filter paper impregnated with Griess reagent was used as the platform of the sensor and a SONY Xperia Z5 cell phone was used for image capturing from the sensor surface. To generate second-order data, the F-number of the camera's sensor was changed as an instrumental parameter. Two calibration models were constructed by unfolded partial least squares-residual bilinearization (U-PLS/RBL) and multiway-PLS/RBL (N-PLS/RBL) and then, their performance for prediction of nitrite concentration in test samples was evaluated and the results confirmed a good performance for U-PLS/RBL (REP = 3.25 ppm, RMSEP = 8.82 ppm, RMSEC = 4.62 ppm, Q 2 = 0.99, γ -1 = 0.05 and LOD = 0.1 ppm) which was better than that for N-PLS/RBL (REP = 13.98 ppm, RMSEP = 37.86 ppm, RMSEC = 6.46 ppm, Q 2 = 0.98, γ -1 = 0.07 and LOD = 0.15 ppm) in predicting concentration of nitrite in test samples which motivated us to choose it for the analysis of cabbage, carrot, lettuce, watermelon, onion, potato, kielbasa and sausage as real samples.

17.
Heliyon ; 5(10): e02755, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31720481

RESUMO

In this work, a novel biosensor was fabricated for detection of DNA damage induced by 4-nonylphenol (NP) and also determination of NP. To achieve this goal, a glassy carbon electrode (GCE) was modified with chitosan (Chit), gold nanoparticles (Au NPs) and DNA-multiwalled carbon nanotubes (DNA-MWCNTs). Then, the DNA-MWCNTs/Au NPs/Chit/GCE was incubated with methylene blue (MB) to obtain MB-DNA-MWCNTs/Au NPs/Chit/GCE in which MB was used as the redox indicator. The modifications applied to the GCE were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopic (EDS) and theoretical evidence. MB is a derivative of anthraquinone which can intercalate into double helix structure of DNA. By treating MB-DNA-MWCNTs/Au NPs/Chit/GCE with NP, a higher R ct was observed because the insertion of the NP may result in a more negative charge environment on the DNA surface which hinders accessibility of [Fe(CN)6]3-/4- anion to the electrode surface. Change in the EIS response of the biosensor in the presence of NP was used to develop a novel system for monitoring the DNA damage induced by NP. The EIS technique was also used to develop a sensitive electroanalytical method for determination of NP.

18.
Heliyon ; 5(7): e02153, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31388584

RESUMO

This work reports the results of an interesting study related to the investigation of interactions of bromocriptine (BCP) with human serum albumin (HSA) by mathematicall modelling of voltammetric and spectroscopic data into an augmented data matrix and its resolution by multivariate curve resolution-alternating least squares (MCR-ALS). The quality of the results obtained by MCR-ALS was examined by MCR-BANDS and its outputs confirmed the absence of rotational ambiguities in the MCR-ALS results. BCP-HSA interactions were also modeled by molecular docking methods to verify the results obtained from experimental sections and fortunately, they were compatible. Hard modeling of the experimental data by EQUISPEC helped us to calculate the binding constant of the complex formed from BCP-HSA interactions which was in a good agreement with that of calculated from direct analysis of the experimental data. Finally, with the help of two different amperometric measurements based on BCP-HSA interactions a novel electroanalytical method was developed for biosensing of HSA in serum samples.

19.
Int J Biol Macromol ; 136: 377-385, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31207328

RESUMO

This paper reports results of a valuable study on investigation of inhibitory effects of the sulfonamide derivative of quercetin (QD) on human carbonic anhydrase II (CA-II) by electrochemical and chemometrical approaches. To achieve this goal, a glassy carbon electrode (GCE) was chosen as the sensing platform and different electrochemical techniques such as cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were used to investigate and comparing inhibitory effects of quercetin (Q) and QD on CA-II. By the use of EQUISPEC, SPECFIT, SQUAD and REACTLAB as efficient hard-modeling algorithms, bindings of Q and QD with CA-II were investigated and the results confirmed that the QD inhibited the CA-II stronger than Q suggesting a highly relevant role of QD's-SO2NH2 group in inhibiting activity and also was confirmed by docking studies. Finally, a novel EIS technique based on interaction of Q and CA-II was developed for sensitive electroanalytical determination of CA-II and in this section of our study, the sensitivity of the developed electroanalytical methodology was improved by the modification of the GCE was with multi-walled carbon nanotubes-ionic liquid.


Assuntos
Anidrase Carbônica II/antagonistas & inibidores , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/farmacologia , Modelos Moleculares , Quercetina/química , Quercetina/farmacologia , Sulfonamidas/química , Técnicas Biossensoriais , Anidrase Carbônica II/química , Quimioinformática , Eletroquímica , Humanos , Conformação Proteica
20.
Talanta ; 201: 350-357, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122434

RESUMO

In this work, a novel electrochemical biosensor has been fabricated based on step-by-step modification of a glassy carbon electrode (GCE) with methylene blue (MB)-DNA/multiwalled carbon nanotubes (MWCNTs)-chitosan (CS)/palladium nanoparticles (Pd NPs)/fullerene C60 (C60) for voltammetric and impedimetric detection of DNA damage induced by bisphenol A (BPA). Modifications applied to the GCE were characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. The EIS and DPV responses of the biosensor were increased and decreased, respectively, by the DNA damage induced by BPA which led us to develop novel systems for detection of DNA damage. Our records confirmed that the biosensor was able to rapid and sensitive detection of DNA damage induced by BPA. Finally, according to the developed systems for detection of DNA damage, we have developed voltammetric and impedimetric methods for determination of BPA.


Assuntos
Compostos Benzidrílicos/efeitos adversos , Compostos Benzidrílicos/análise , Dano ao DNA/efeitos dos fármacos , DNA/química , Fenóis/efeitos adversos , Fenóis/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Quitosana/química , Espectroscopia Dielétrica/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção , Nanopartículas Metálicas/química , Azul de Metileno/química , Nanotubos de Carbono/química , Paládio/química , Reprodutibilidade dos Testes
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