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1.
J Environ Manage ; 363: 121257, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38850913

RESUMEN

The redesigned engineering building of nanocomposite (NCP) depends on metal oxides of palladium oxide (PdO) nanoparticles (NPs) conjugate with the n-type semiconductor of strontium oxide (SrO) NPs on the electron carrier surface of graphene oxide (GO) and reduce graphene oxide (rGO) nanosheet is the main target of the current work. The low efficiency of PdO (n-type) and SrO (p-type) gave an overview of the increasing generation electron efficiency via building the ohmic area on the GO and rGO surface using the Z-scheme mechanism. The efficiency of the NCP surface for destroying organic pollutants such as mixed dyes of Rhodamine B and methylene blue (RhB/MB), as against insecticides like imidacloprid, and the removal of heavy metals such as chromium ions was studied. The production of clean water against pollutants materials was investigated through adsorption and photocatalytic processes, electrochemical, and spectroscopy methods to detect the activity of NCP. The rate constant of the adsorption pollutants is 0.1776 min-1 (MB), 0.3489 min-1 (RhB), 0.3627 min-1 (imidacloprid), and 0.5729 min-1 (Cr3+). The photocatalytic rate recorded at 0.01218 min-1 (MB), 0.0096 min-1 (RhB), appeared degradation rate at 0.0086 min-1 (imidacloprid), 0.0019 min-1 (Cr6+), and 0.0471 min-1 (Cr3+). The adsorption and photocatalytic efficiency of nanocatalyst (NCP) was calculated at 91% (RhB), 93% (MB), 73% (imidacloprid), 63% (Cr3+), while the photocatalytic efficiency is 63% (RhB), 94% (MB), 86% (imidacloprid), 33% (Cr3+). The recyclability of NCP was tested for five cycles, and the efficiency was discovered at 55% after the fifth cycle. The cytotoxicity of NCP was studied to detect the safety of the fabricated materials. The study validates that the fabricated nanocomposite exhibits great potential as an innovative material for producing clean water.

2.
Int J Biol Macromol ; 264(Pt 2): 130634, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38460624

RESUMEN

The nature of nano molecules as a self-assembled nanocomposite surface depends on the nanoparticles of sodium butyrate, cellulose, and pycnogenol; the synthesis is achieved via precipitation and grinding methods. The excellent functionalized surface of nanocomposite (NCP) enables the loading of the selected drugs, where the efficiency of the NCP surface arrived at 92.2 %. The electrochemical behavior emphasized the success of a functionalized NCP surface for incorporation with drugs for the drug delivery system, the results of cytotoxicity detect the effect of NCP on the mouse normal liver (BNL) cells, where the high and low concentrations on the BNL cells have a safe dose. Cell viability with BNL cells was reported at 101.8 % with10 µL and 100.12 % with 100 µL, the interaction between the NCP and the human serum albumin (HSA) at room temperature. The low interaction rate with the glutamate and increased binding with the oxidized glutathione disulfide (GSSG) and reduced glutathione (SGH) reflect the antioxidant activity of NCP. The strong binding of NCP with biomolecules such as glucose is referred to as the biosensor property. The results recommend that NCP is an excellent nanocarrier for drug delivery and glucose biosensors for diabetes.


Asunto(s)
Técnicas Biosensibles , Nanocompuestos , Humanos , Animales , Ratones , Glucosa , Antioxidantes/farmacología , Glutatión , Nanocompuestos/química , Disulfuro de Glutatión , Técnicas Biosensibles/métodos
3.
Int J Mol Sci ; 24(18)2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37762406

RESUMEN

The current study describes the encapsulation of hydroxychloroquine, widely used in traditional medicine due to its diverse pharmacological and medicinal uses, in chitosan nanoparticles (CNPs). This work aims to combine the HCQ drug with CS NPs to generate a novel nanocomposite with improved characteristics and bioavailability. HCQ@CS NPs are roughly shaped like roadways and have a smooth surface with an average size of 159.3 ± 7.1 nm, a PDI of 0.224 ± 0.101, and a zeta potential of +46.6 ± 0.8 mV. To aid in the development of pharmaceutical systems for use in cancer therapy, the binding mechanism and affinity of the interaction between HCQ and HCQ@CS NPs and BSA were examined using stopped-flow and other spectroscopic approaches, supplemented by molecular docking analysis. HCQ and HCQ@CS NPs binding with BSA is driven by a ground-state complex formation that may be accompanied by a non-radiative energy transfer process, and binding constants indicate that HCQ@CS NPs-BSA was more stable than HCQ-BSA. The stopped-flow analysis demonstrated that, in addition to increasing BSA affinity, the nanoformulation HCQ@CS NPS changes the binding process and may open new routes for interaction. Docking experiments verified the development of the HCQ-BSA complex, with HCQ binding to site I on the BSA structure, primarily with the amino acids, Thr 578, Gln 579, Gln 525, Tyr 400, and Asn 404. Furthermore, the nanoformulation HCQ@CS NPS not only increased cytotoxicity against the A549 lung cancer cell line (IC50 = 28.57 ± 1.72 µg/mL) compared to HCQ (102.21 ± 0.67 µg/mL), but also exhibited higher antibacterial activity against both Gram-positive and Gram-negative bacteria when compared to HCQ and chloramphenicol, which is in agreement with the binding constants. The nanoformulation developed in this study may offer a viable therapy option for A549 lung cancer.


Asunto(s)
Quitosano , Neoplasias Pulmonares , Nanopartículas , Humanos , Simulación del Acoplamiento Molecular , Quitosano/química , Hidroxicloroquina/farmacología , Liberación de Fármacos , Antibacterianos , Bacterias Gramnegativas/metabolismo , Bacterias Grampositivas/metabolismo , Nanopartículas/química , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 302: 123063, 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-37390719

RESUMEN

The target of the current study is to create a novel hybrid nanocomposite (Cs@Pyc.SOF) by combining the anti-hepatitis C virus (HCV) drug sofosbuvir with the nano antioxidant pycnogenol (Pyc) and nano biomolecules like chitosan nanoparticles (Cs NPs). The characterization procedure works to verify the creation of nanocomposite (NCP) using several different techniques. UV-Vis spectroscopy is used to measure SOF loading efficiency. The various concentrations of the SOF drug were used to determine the binding constant rate Kb, which was found to be 7.35 ± 0.95 min-1 with an 83% loading efficiency. At pH 7.4, the release rate was 80.6% after two hours and 92% after 48 h, whereas at pH 6.8, it was 29% after two hours and 94% after 48 h. After 2 and 48 h, the release rate in water was 38% and 77%, respectively. . The SRB technique for fast screening is used for the cytotoxicity test, where the investigated composites show a safety status and high viability against the examined cell line. The cytotoxicity assay of the SOF hybrid materials has been identified with cell lines like mouse normal liver cells (BNL). So, Cs@Pyc.SOF was recommended as a substitute medication for the therapy of HCV, but the results need clinical studies.


Asunto(s)
Quitosano , Hepatitis C , Animales , Ratones , Sofosbuvir , Antivirales/uso terapéutico , Hepacivirus , Preparaciones Farmacéuticas , Quimioterapia Combinada , Hepatitis C/tratamiento farmacológico , Análisis Espectral , Ribavirina
5.
Int J Biol Macromol ; 234: 123633, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36791938

RESUMEN

Lung cancer progresses without obvious symptoms and is detected in most patients at late stages, causing a high rate of mortality. Avocado peels (AVP) were thought to be biowaste, but they have antioxidant and anticancer properties in vitro. Chitosan nanoparticles (Cs-NPs) were loaded with various plant extracts, increasing their in vitro and in vivo anticancer activities. Our goal was to load AVP onto Cs-NPs and determine the role of AVP-extract or AVP-loaded Cs-NPs in controlling the progression of lung cancer caused by urethane toxicity. The AVP-loaded chitosan nano-combination (Cs@AVP NC) was synthesized and characterized. Our in vitro results show that Cs@AVP NC has higher anticancer activity than AVP against three human cancer cell lines. The in vivo study proved the activation of apoptosis in lung cancer cells with the Cs@AVP NC oral treatment more than the AVP treatment. Additionally, Cs@AVP NC-treated animals showed significantly higher p53 and Bax-expression levels and lower NF-κB p65 levels in their lung tissues than in positive control animals. In conclusion, our study demonstrated the superior anticancer potency of Cs@AVP NC over AVP extract and its ability to inhibit lung cancer proliferation. Therefore, oral consumption of Cs@AVP NC might be a promising treatment for lung cancer.


Asunto(s)
Quitosano , Neoplasias Pulmonares , Nanopartículas , Persea , Ratones , Animales , Humanos , Uretano , Neoplasias Pulmonares/tratamiento farmacológico , Extractos Vegetales/farmacología
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 286: 121949, 2023 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-36228488

RESUMEN

The target is a novel nano-combination membrane (NCM) via Terbium oxide nanoparticles (Tb2O3 NPs) and nickel oxide (NiO NPs) which integrates on the graphene oxide (GO) surface. The NCM is characterized by different tools such as X-ray diffraction (XRD), UV-visible spectrophotometer (UV-vis), and Scanning electron microscopy (SEM)for removing organic pollutants. The precipitation method has been applied for fabricating the selected metal oxides (MOs), where the terbium chloride and nickel chloride are used as precursors for fabricating the metal oxides (MOs) NPs that formed with potassium hydroxide in the solution. The photocatalytic activity of fabricated NCM has been noticed with the quenching of mixed Rhodamine B (RhB) and methyl orange (MO) dyes at various times for water treatment. UV-vis spectra confirmed the excellent efficiency against organic pollution degradation. After exposure to the light for 100 min, the photodegradation efficacy of MB and RhB appeared at 46.88 % and 16.4 %, with GO@Tb2O3, by GO@Tb2O3.NiO the efficiency was 54.8 % and 32.3 % after 100 min, while GO@NiO has degradation efficiency at 43 % and 17.3 % for MB and RhB respectively. The cytotoxicity of NCM is detected with hepatocellular carcinoma (HepG2) and breast adenocarcinoma (MCF-7), the result illustrated that the fabricated NCM does not affect the cancer cells with the 10 µL, but with the higher concentration of 100 µL, the cell lysis was observed. The results of photocatalytic and cytotoxicity are recommended using these fabricated NCM in water treatment.


Asunto(s)
Óxidos , Purificación del Agua , Terbio , Catálisis
7.
Biomimetics (Basel) ; 7(4)2022 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-36412701

RESUMEN

Reaction of bis(2-picolyl)amine (BPA) with Ni(II) salt yielded [(BPA)NiCl2(H2O)] (NiBPA). The Ni(II) in NiBPA bound to a BPA ligand, two chloride, and one aqua ligands. Because most medications inhibit biological processes by binding to a specific protein, the stopped-flow technique was used to investigate DNA/protein binding in-vitro, and a mechanism was proposed. NiBPA binds to DNA/protein more strongly than BPA via a static quenching mechanism. Using the stopped-flow technique, a mechanism was proposed. BSA interacts with BPA via a fast reversible step followed by a slow irreversible step, whereas NiBPA interacts via two reversible steps. DNA, on the other hand, binds to BPA and NiBPA via the same mechanism through two reversible steps. Although BSA interacts with NiBPA much faster, NiBPA has a much higher affinity for DNA (2077 M) than BSA (30.3 M). Compared to NiBPA, BPA was found to form a more stable BSA complex. When BPA and NiBPA bind to DNA, the Ni(II) center was found to influence the rate but not the mechanism, whereas, for BSA, the Ni(II) center was found to change both the mechanism and the rate. Additionally, NiBPA exhibited significant cytotoxicity and antibacterial activity, which is consistent with the binding constants but not the kinetic stability. This shows that in our situation, biological activity is significantly more influenced by binding constants than by kinetic stability. Due to its selectivity and cytotoxic activity, complex NiBPA is anticipated to be used in medicine.

8.
Int J Biol Macromol ; 216: 251-262, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35780919

RESUMEN

The present work-study the decreasing fluoride ions toxicity on the rat heart via loading them on the chitosan nanoparticles (Cs NPs) surface to form the biologically compatible composite (Cs@NaF). The obtained nanocomposite was characterized by different techniques such as field emission scanning electron microscopy (FEG-SEM), zeta potential, and x-ray diffraction (XRD). The biochemical parameters in the albino rats perform, where twenty-eight male adult Sprague Dawley rats (average body weight of 150 ± 10 g) were obtained from the Faculty of Agriculture, Alexandria University, then acclimatized for two weeks before the experiment and divided into four groups in galvanized wire cages at room temperature (22-25 °C) with a 12-h photoperiod and fed a well-balanced commercial diet. The blood samples were obtained from the vena cava of the rat heart via estimation of the troponin T, Lactate dehydrogenase, and creatine phosphokinase. Also, immunoglobulins (IgA, IgM, and IgG) and hematological measurements have been performed on the rat heart. To express all of the data, the mean and standard error of the mean are utilized by (ANOVA), followed by Tukey's multiple comparison test. The modified chitosan with fluoride decreases the toxicity of fluoride via improving the rat heart function due to the presence of Cs NPs helped to mitigate some of the negative effects of fluoride therapy.


Asunto(s)
Quitosano , Nanocompuestos , Nanopartículas , Animales , Quitosano/química , Fluoruros/toxicidad , Humanos , Sistema Inmunológico , Masculino , Nanocompuestos/química , Nanopartículas/química , Ratas , Ratas Sprague-Dawley
9.
Int J Biol Macromol ; 207: 402-413, 2022 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-35278509

RESUMEN

The present work-study the improvement of the loading and release efficiency of sofosbuvir drug (SOF) for anti-hepatitis C virus (HCV) by the combination process with ß-cyclodextrin (ßCD) basket to form a novel self-assembly ßCD-SOF which load on the chitosan nanoparticle (Cs NPs) to form a novel hybrid composite (Cs@ßCD-SOF). The characterization process performs for confirming the formation of hybrid composite with various methods. The loading efficiency of SOF is performed by UV-Vis spectroscopy, which is reported at 94.54% for Cs@ßCD-SOF, while in the reverse case the efficiency is ßCD-SOF@Cs 65.2%. The binding constant (Kb) was reported at 1.33 ± 0.02, and 0.1069 ± 0.03 min-1for Cs@ßCD-SOF and ßCD-SOF@Cs, respectively. The release process of SOF is reported by UV-Vis spectra at 271 nm with 30 min intervals, at pH 7.4 the release efficiency is 67% after 6 h, and 78% after 21 h, while it gave 61% release efficiency at pH 6.8 after time 6 h, and 63% after 21 h. The cytotoxicity assay of the SOF capsulated hybrid materials (ßCD-SOF and Cs@ßCD-SOF) has been detected with three different types of cell lines like mouse normal liver cells (BNL), hepatocellular carcinoma (HepG2), and breast adenocarcinoma (MCF-7). SRB method for the quick screening is used for the cytotoxicity assay of the SOF capsulated materials, where the examined composites appear a safety status and high viability against the examined cell line. The FRAP method is used to detect the antioxidant activities of SOF capsulated materials. The recommendation for using a safe alternative SOF drug based on Cs NPs and ßCD which give on loading and release efficiency compared to SOF drugs, but the clinical trials are an important step.


Asunto(s)
Quitosano , Hepatitis C , Nanopartículas , beta-Ciclodextrinas , Animales , Antivirales/farmacología , Quitosano/química , Quimioterapia Combinada , Genotipo , Hepacivirus , Hepatitis C/tratamiento farmacológico , Ratones , Nanopartículas/química , Preparaciones Farmacéuticas , Sofosbuvir/farmacología , Resultado del Tratamiento , beta-Ciclodextrinas/química
10.
Fish Shellfish Immunol ; 119: 516-523, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34718125

RESUMEN

Recently, nanotechnology has been greatly developed to provide the aquaculture industry with new beneficial nanomaterials to improve the health and welfare of aquatic animals. Herein, an eight-week experiment was designed to examine the dietary impacts of sodium butyrate nanoparticles (SB-NPs) on the hematological profile, blood proteins, immunological indices, antioxidant capacity, and expression analysis of cytokines and antioxidant-related genes in Oreochromis niloticus. Fish were randomly assigned into 5 experimental groups (3 replicates per group) and were fed diets supplemented with 5 levels of SB-NPs as 0.0 (control), 0.5, 1.0, 1.5, and 2.0 mg kg-1. The results revealed that supplementing diets with SB-NPs (1.0-2.0 mg kg-1) significantly elevated erythrocyte and leukocyte counts, hemoglobin concentrations, hematocrit values, total albumin, globulin, serum lysozyme activities, and total immunoglobulin M values compared with the control group. Notably, the highest levels of the parameters mentioned above were noticed in the group fed diet supplemented with 1.5 mg kg-1 SB-NPs. Moreover, dietary SB-NPs modulated the fish's antioxidant defense mechanisms, whereas there was a significant increase in hepatic superoxide dismutase, catalase, and glutathione peroxidase enzyme activities along with a significant decline in hepatic malondialdehyde concentrations in fish groups fed diets supplemented with SB-NPs (1.0-2.0 mg kg-1). A significant upregulation of antioxidant enzyme genes (gpx and sod), anti-inflammatory cytokine (il-10), and pro-inflammatory cytokines (il-1ß and il-8) were noticed in liver tissues of SB-NPs groups (0.5-1.5 mg kg-1). The highest mRNA expression folds of the above genes were recorded in the fish group fed diet supplemented with 1.5 mg kg-1 SB-NPs. In this context, we hypothesized that dietary supplementation with SB-NPs can boost the antioxidant status and immunity of O. niloticus. However, further research studies are still recommended.


Asunto(s)
Cíclidos , Enfermedades de los Peces , Nanopartículas , Alimentación Animal/análisis , Animales , Antioxidantes , Ácido Butírico , Cíclidos/genética , Citocinas/genética , Dieta/veterinaria , Suplementos Dietéticos , Expresión Génica , Hígado
11.
Int J Biol Macromol ; 190: 927-939, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34480910

RESUMEN

The incorporation between nano-polyvinyl alcohol (PVA) and nano-chitosan (Cs) to produce sandwich nanohybrid (SNH) for water treatment and improvement the adsorption of sofosbuvir drug (SOF). The photocatalytic activity and formation of reactive oxygen species (ROS) were detected with oxidation of organic dyes such as Rhodamine B (RhB), methylene blue (MB), and methyl orange (MO). The effect of SNH on the release of SOF in blood and inside the cells at pH 7.4 and pH 6.8, respectively were observed by UV-Visible spectroscopy (UV-Vis). The binding constant (Kb) was reported at 0.0035 min-1 and the loading constant at 0.0024 min-1, while the release efficiency was 42.6% at pH 7.4 and 74.7% at pH 6.8. The efficiency of photocatalytic activity against organic dyes MO, MB, and RhB are detected at 2.4% and 1%, and 42%, respectively. The cytotoxicity of SNH has been observed with MDA-MB-231 and HepG2 cell line with three concentrations of SNH, where the little concentration has low effect on the HepG2 and high viability, this result was reversed with the high concentration, also the yellow color due to the lysis of the cells. The antioxidant of the SNH was detected by FRAP technique.


Asunto(s)
Quitosano/química , Sistemas de Liberación de Medicamentos , Hepacivirus/fisiología , Nanopartículas/química , Alcohol Polivinílico/química , Sofosbuvir/farmacología , Agua/química , Antioxidantes/farmacología , Calibración , Catálisis , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Hepacivirus/efectos de los fármacos , Humanos , Fenómenos Ópticos , Rodaminas/química , Sofosbuvir/química , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 261: 120008, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34087770

RESUMEN

Self-assembly of Sofosbuvir drug (SOF) anti-hepatitis C virus (HCV) with bio-polymeric nanoparticles such as chitosan nanoparticles (Cs NPs) and polyvinyl alcohol nanoparticles (PVA NPs), the novel composites have been characterized successfully by different analysis such as Energy-dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM), UV-Visible spectrophotometer (UV-Vis) and Fourier Transmittance Infrared (FT-IR). The improvement of the Sofosbuvir effect as a result of loading drug on the bio-polymer NPs surface has been detected by the UV-Vis, and fluorescence spectroscopy techniques. The improvement of SOF efficiency was revealed via studying the drug release of SOF from biopolymers NPs surface at pH 7.4, UV-Vis spectra used for the releasing process. The binding constant (Kb) value was reported at 0.000055 and 0.3613 min-1 for Cs and PVA NPs respectively. Also, the value of KSV was documented at 0.0014 and 7.16 min-1 for Cs@SOF and PVA@SOF hybrid nanocomposite. The incorporation rate (k) of SOF on the surface of biopolymer nano molecules was calculated to be 0.00812 and 0.0165 min-1 for Cs and PVA NPs, respectively. Besides the observed value of (n) was close to the unit 0.74 and 0.86 for Cs and PVA NPs, respectively. The SOF released from Cs NPs surface was documented at 0.09 mg after 24 h, while PVA NPs reported at 0.7 mg at the same time and the release efficiency is 56.5 and 73% for Cs@SOF and PVP@SOF, respectively. From the results, we suggest Cs/SOF and PVA/SOF hybrid nanocomposites have spectroscopic results that make them promising candidate drugs, but need to the clinical trials.


Asunto(s)
Quitosano , Nanopartículas , Preparaciones Farmacéuticas , Liberación de Fármacos , Polímeros , Sofosbuvir , Espectroscopía Infrarroja por Transformada de Fourier
13.
Artículo en Inglés | MEDLINE | ID: mdl-16524759

RESUMEN

The electronic absorption spectra of some 6-chloro,2-pyridyl hydrazones are studied in seven organic solvents of different polarity. The absorption bands are assigned to the corresponding electronic transitions and the effect of solvent parameters on the charge transfer energy (E(CT)) is investigated. The spectra in buffer solutions of varied pH are also studied and utilized for the determination of the acid dissociation constants of the compounds under study. The fluorescence spectra were recorded for one of the studied compounds in six solvents, the solvent effect on the photoquantum yield and spectral pattern are also studied. Bands of diagnostic importance in the IR spectra and signals in the (1)H NMR spectra are assigned. The results of the present investigation are supported by some MO calculations using the atom super position and electron delocalization molecular orbital theory (ASED-MO) and Gaussian 94 program. The geometry is optimized using the PM3 method.


Asunto(s)
Hidrazonas/química , Espectroscopía de Resonancia Magnética , Conformación Molecular , Estructura Molecular , Soluciones , Solventes , Espectrometría de Fluorescencia , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta
14.
Neuro Endocrinol Lett ; 26(3): 247-52, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15990730

RESUMEN

MALDI-TOF mass spectrometry, 1H NMR spectrometry, the continuous variation method and molecular modeling by MM3 calculation confirmed our earlier studies showing that gonadotropin-releasing hormone (GnRH) forms complex with copper(II) ion with the binding ratio 1:1. The copper(II) complex formed at physiological pH has a square planar configuration and GnRH complexes with nickel(II) and cobalt(II) ions are less stable than that of copper(II).


Asunto(s)
Hormona Liberadora de Gonadotropina/química , Metales Pesados/química , Animales , Cobre/química , Níquel/química , Resonancia Magnética Nuclear Biomolecular , Protones , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
15.
Talanta ; 62(2): 317-22, 2004 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-18969297

RESUMEN

The steady state and time-resolved fluorescence study of 2-amino-5,6-dimethyl-benzimidazole (ADBI) have been studied in aqueous solution of beta-cyclodextrin (beta-CD). The fluorescence decays were analyzed by global analysis and distribution analysis in order to get insight about the inclusion process. The fluorescence lifetime of ADBI is increased in beta-CD and an enhancement of the emission, is observed, together with negligible changes in the energy of ADBI in beta-CD. The experimental data show that beta-CD reacts with ADBI to form a 1:1 host-guest complex with association constant was determined to be 2074+/-77M(-1). Both global analysis and distribution analysis of the fluorescence decays support the formation of only 1:1 inclusion complex. AM1 calculation shows that the size of ADBI was appropriate for good insertion within the beta-CD cavity and the inclusion of ADBI inside the beta-CD cavity should takes place from the side of the amino group substituent.

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