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1.
Sci Rep ; 13(1): 7857, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37188721

RESUMO

Plasma processing appears to be the mainstay of food preservation in the present day due to its effectiveness in controlling microorganisms at low temperatures. Legumes are usually soaked before cooking. Six chickpea varieties (Kripa, Virat, Vishal, Vijay, Digvijay, and Rajas) were soaked in distilled water at room temperature, and Peleg model was fitted after plasma treatment. Cold plasma treatment was used at 40, 50 and 60 Watt with exposure times of 10, 15 and 20 min. K1 (Peleg rate constant) consistently decreased from 32.3 to 4.3 × 10-3 (h % - 1) for all six chickpea cultivars, indicating an increased water absorption rate with increasing plasma power and treatment time. It was lowest in 60 W 20 min plasma treatment in Virat cultivar. K2 (Peleg capacity constant) ranged from 9.4 to 12 × 10-3 (h % - 1) for all six chickpea cultivars. Thus, plasma treatment showed no effect on water uptake capacity (K2), as it did not increase or decrease consistently with increasing plasma power and treatment time. Fitting the Peleg model successfully revealed the correlation between the water absorption of chickpea cultivars. The model fit ranged from R2 ≥ 0.9873 to 0.9981 for all six chickpea cultivars.


Assuntos
Cicer , Fabaceae , Gases em Plasma , Água/farmacologia , Gases em Plasma/farmacologia , Culinária
2.
RSC Adv ; 12(22): 14246-14259, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35558835

RESUMO

The simultaneous presence of hazardous chemicals and pathogenic microorganisms in wastewater is tremendously endangering the environment and human health. Therefore, developing a mitigation strategy for adequately degrading toxic compounds and inactivating/killing microorganisms is urgently needed to protect ecosystems. In this paper, the synergetic effects of the photocatalytic activity of TiO2 and Cu-TiO2 nanoparticles (NPs) and the oxidation processes of non-thermal atmospheric pressure plasma (NTAPP) were comprehensively investigated for both the inactivation/killing of common water contaminating bacteria (Escherichia coli (E. coli)) and the degradation of direct textile wastewater (DTW). The photocatalytic NPs were synthesized using the hydrothermal method and further characterized employing field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), ultraviolet-visible diffuse reflection spectroscopy (UV-Vis DRS) and photoluminescence (PL). Results revealed the predominant presence of the typical anatase phase for both the flower-like TiO2 and the multipod-like Cu-TiO2 structures. UV-Vis DRS and PL analyses showed that the addition of Cu dopants reduced the bandgap and increased oxygen defect vacancies of TiO2. The inactivation of E. coli in suspension and degradation of DTW were then examined upon treating the aqueous media with various plasma alone and plasma/NPs conditions (Ar plasma, Ar + O2 plasma and Ar + N2 plasma, Ar plasma + TiO2 NPs and Ar plasma + Cu-TiO2 NPs). Primary and secondary excited species such as OH˙, O, H and N2* generated in plasma during the processes were recognized by in situ optical emission spectrometry (OES) measurements. Several other spectroscopic analyses were further employed to quantify some reactive oxygen species (ROS) such as OH, H2O2 and O3 generated during the processes. Moreover, the changes in the pH and electrical conductivity (EC) of the solutions were also assessed. The inactivation of bacteria was examined by the colony-forming unit (CFU) method after plating the treated suspensions on agar, and the degradation of organic compounds in DTW was further validated by measuring the total organic carbon (TOC) removal efficiency. All results collectively revealed that the combinatorial plasma-photocatalysis strategy involving Cu-TiO2 NPs and argon plasma jet produced higher concentrations of ROS and proved to be a promising one-step wastewater treatment effectively killing microorganisms and degrading toxic organic compounds.

3.
Sci Rep ; 11(1): 13425, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183731

RESUMO

Cold plasma has proven itself as a promising method of food preservation by controlling food spoilage bacteria at very low temperatures. It is showing potential for insect control. Synthetic pesticides are mostly used to control Callosobruchus chinensis L. (Chrysomelidae: Coleoptera) to which it has developed resistance. The prospective potential of cold plasma treatment to control pulse beetle infestation of chickpea in the storage for about four years of plasma treatment was studied. The four chickpea cultivars were treated with cold plasma at different power 40, 50, and 60 W each for 10, 15, 20 min. Plasma treated and untreated chickpeas were stored in an airtight ziplock pouch. At regular intervals, the grains were observed for infestation. It was found most effective in controlling the pulse beetle infestation of treated chickpea samples. While plasma untreated chickpeas were attacked and damaged mostly by pulse beetle within the first quarter of the storage study. To avoid the problems created by the use of pesticides cold plasma treatment is found to be the best alternative in the protection of chickpea invasion by pulse beetle during a longer storage period. The findings in the present research may be used for the preparation of legumes which may also soak and cook faster like quick-cooking legumes and preserved for years without invasion of pulse beetle.

4.
Environ Geochem Health ; 43(2): 649-662, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31679080

RESUMO

One of the major environmental issues of textile industries is the discharge of large quantities of textile effluents, which are source of contamination of water bodies on surface of earth and quality of groundwater. The effluents are toxic, non-biodegradable, carcinogenic and prodigious threats to human and aquatic creatures. Since textile effluents can be treated efficiently and effectively by various advanced oxidation processes (AOPs). Among the various AOPs, cold atmospheric pressure plasma is a promising method among many prominent techniques available to treat the effluents. In this paper, we report about the degradation of simulated effluent, namely Direct Orange-S (DO-S) aqueous solution, using nonthermal atmospheric pressure plasma jet. The plasma treatment of DO-S aqueous solution was carried out as a function of various operating parameters such as potential and treatment time. The change in properties of treated DO-S dye was investigated by means of various analytical techniques such as high-performance liquid chromatography, UV-visible (UV-Vis) spectroscopy and determination of total organic content (TOC). The reactive species present in the samples were identified using optical emission spectrometry (OES). OES results confirmed that the formation of reactive oxygen and nitrogen species during the plasma treatment in the liquid surface was responsible for dye oxidation and degradation. Degradation efficiency, as monitored by color removal efficiency, of 96% could be achieved after 1 h of treatment. Concurrently, the TOC values were found to decrease with plasma treatment, implying that the plasma treatment process enhanced the non-toxicity nature of DO-S aqueous solution. Toxicity of the untreated and plasma-treated dye solution samples was studied using Escherichia coli (E. coli) and Staphylococcus (S. aureus) organisms, which demonstrated that the plasma-treated dye solution was non-toxic in nature compared with untreated one.


Assuntos
Corantes/metabolismo , Resíduos Industriais , Gases em Plasma , Indústria Têxtil , Poluentes Químicos da Água/metabolismo , Pressão Atmosférica , Corantes/toxicidade , Escherichia coli/efeitos dos fármacos , Humanos , Nitrogênio , Staphylococcus aureus/efeitos dos fármacos
5.
J Hazard Mater ; 405: 124264, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33153792

RESUMO

In this paper, the photocatalytic activity of plasma-functionalized Cu-doped TiO2 nanoparticles (NPs) and the oxidization process of atmospheric pressure plasma jet were combined for the degradation of reactive red-198 (RR-198) in aqueous solution. The first part of the study was thus devoted to subject Cu-‒TiO2 NPs synthetized by the sol-gel method to various plasma treatments operating in air, argon, oxygen and nitrogen to improve their degradation efficiency. The physicochemical properties of the NPs were then assessed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. XRD results indicated the predominant presence of the anatase phase which is the most photoactive form of TiO2. The XPS analysis revealed that the different plasma treatments triggered the formation of oxygen vacancies, Ti3+ oxidation state and Cu2+ oxidation state on the surface of Cu-‒TiO2 NPs. These changes, known to prevent the recombination of electron-hole pair, have led to a reduction in the bandgap that was more pronounced for the N2 plasma-treated NPs. The second part of the paper explored the actual degradation of RR-198 in aqueous solution by an Ar plasma treatment alone or combined with the plasma pre-treated Cu-‒TiO2 NPs. Optical emission spectroscopy (OES) and spectrophotometric analyses showed that the synergetic effect of Ar plasma and N2 plasma-treated NPs produced the highest concentration of OH• radicals and H2O2 species which led to the highest RR-198 degradation efficiency. This was further confirmed by pH, electrical conductivity and total organic carbon (TOC) removal measurements. The degradation of RR-198 was determined using UV-Vis spectroscopy and high-performance liquid chromatography (HPLC). Overall, it can be concluded that plasma-assisted processes illustrated by a combination of a direct plasma treatment with plasma-functionalized Cu-‒TiO2 NPs can be used in various textile and pharmaceutical industries as a highly effective treatment of their effluents before discharging.

6.
RSC Adv ; 10(59): 35709-35717, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-35517122

RESUMO

This paper investigated the degradation of the pharmaceutical drug Valsartan (VS) using non-equilibrium atmospheric pressure plasma (NEAPP) with various operating conditions. The heterogeneous photocatalyst ZnO nanoparticles (NP's) were synthesized using a hydrothermal process. The morphology, chemical composition and structure of as-synthesized ZnO NPs were examined by Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Then, VS degradation was examined in three subsequent treatment conditions including plasma treatment alone, the combination of plasma with as-prepared ZnO NPs and various environments (air, oxygen and hydrogen peroxide) at fixed plasma operating potential and treatment time. The degradation efficiency of plasma-treated VS by various conditions was observed using UV-visible spectroscopy. Optical Emission Spectrometry (OES) was used to characterize the distribution and emission intensity of various reactive species (OH˙, N2-SPS and O) during the degradation processes which plays a vital role in the degradation of VS. The role of OH˙ and H2O2 during the degradation process was further examined by chemical dosimetry and spectroscopic techniques. Furthermore, pH, conductivity and TOC of the untreated and plasma-treated VS were also investigated. The results on the degradation of VS showed that plasma treatment combined with ZnO NP's has a significant effect on degradation of molecules of VS than degradation processes carried out by other experimental conditions due to the formation of higher concentrations of various reactive oxygen and nitrogen species during the degradation processes.

7.
Mater Sci Eng C Mater Biol Appl ; 94: 150-160, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30423696

RESUMO

This work describes the development of antifouling functional coatings on the surface of low density polyethylene (LDPE) films by means of atmospheric pressure non-thermal plasma (APNTP) assisted copolymerization using a mixture of acrylic acid and poly (ethylene glycol). The aim of the study was to investigate the antifouling properties of the plasma copolymerized LDPE films and the same was carried out as a function of deposition time with fixed applied potential of 14 kV. In a second stage, the plasma copolymerized LDPE films were functionalized with chitosan (CHT) to further enhance its antifouling properties. The surface hydrophilicity, structural, topographical and chemistry of the plasma copolymerized LDPE films were examined by contact angle (CA), X-ray diffraction (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Coating stability was also studied in detail over a storage time of 15 days by storing in water and air. The antifouling properties of the plasma copolymerized LDPE films were examined via protein adsorption and platelet adhesion studies. CA study showed significant changes in surface wettability after the coating process. XPS and FTIR analysis proved the presence of a dense multifunctional coating and an efficient immobilization of CHT. Substantial amendments in surface topography were observed, positively enhancing the overall surface hydrophilicity. Finally, in-vitro analysis showed excellent antifouling behavior of the surface modified LDPE films.


Assuntos
Incrustação Biológica , Quitosana/farmacologia , Gases em Plasma/química , Polietileno/química , Polimerização , Adsorção , Animais , Proteínas Sanguíneas/metabolismo , Materiais Revestidos Biocompatíveis/química , Cabras , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Espectroscopia Fotoeletrônica , Adesividade Plaquetária , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Molhabilidade , Difração de Raios X
8.
Klin Monbl Augenheilkd ; 234(4): 464-467, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28142162

RESUMO

Purpose To investigate the state of dark adaptation and macular blood flow in different forms of glaucoma. Methods Eighteen eyes of 18 patients with primary open-angle glaucoma, 14 eyes of 14 patients with pseudoexfoliation glaucoma, and 10 eyes of 10 patients with childhood glaucoma (CG) were examined by means of dark adaptometry, scanning-laser retinal flowmetry, and retinal tomography. Results All glaucomatous eyes had comparable optic disc excavation (one-way ANOVA, p = 0.138). Eyes with CG had significantly lower best-corrected visual acuity than the other groups (Tukey, all p < 0.0001). Macular perfusion was comparable in all three groups (one - way ANOVA, p = 0.08). The delay in rod-cone break time in the CG group was significantly higher than in the other groups (Tukey, all p < 0.0001). The scotopic sensitivity threshold in the CG group was significantly greater than in the other groups (Tukey, all p < 0.01). Conclusion This underlying dysfunction of dark adaptation may contribute, at least to some extent, to the decreased visual perception observed in patients with CG.


Assuntos
Adaptação à Escuridão , Síndrome de Exfoliação/fisiopatologia , Glaucoma de Ângulo Aberto/fisiopatologia , Transtornos da Visão/fisiopatologia , Acuidade Visual , Campos Visuais , Síndrome de Exfoliação/complicações , Síndrome de Exfoliação/diagnóstico , Feminino , Glaucoma de Ângulo Aberto/complicações , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos da Visão/diagnóstico , Transtornos da Visão/etiologia , Testes de Campo Visual
9.
Carbohydr Polym ; 157: 1723-1731, 2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-27987888

RESUMO

The present work deals with aimed to study the effect of cold plasma treatment on the functional and rheological properties of rice starch using two different power levels (40 and 60W). The changes in amylose content, turbidity, pH, water and fat absorption due to plasma treatment were evaluated. Where decrease in the turbidity and pH after the treatment was observed. Gel hydration properties and syneresis study revealed that there is an increase in leaching of amylose molecules after the treatment. Rapid Visco Analyzer examination showed an increase in pasting and final viscosities. From G' and G″ moduli determination we observed that there is decrease in retrogradation tendency of starch gels. XRD did not show any change in A-type pattern but decrease in the relative crystallinity was observed due to depolymerization caused by active plasma species. FTIR shows some of the additional functional groups after treatment. SEM showed formation of fissures on the surface of starch granules due to etching caused by the plasma species. Thus, plasma treatment can be one of the methods for physical modification of starch.


Assuntos
Amilose/química , Oryza/química , Gases em Plasma , Amido/química , Viscosidade
10.
J Food Sci Technol ; 53(6): 2742-51, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27478230

RESUMO

The present study deals with the application of low temperature plasma on basmati rice flour and its effect on functional properties such as gel hydrations properties, flour hydration properties, gelatinization temperatures and antioxidant properties. The water holding capacity and water binding capacity were observed to be increased with increase in plasma power and time of treatment as the air plasma is known to make the surface more hydrophilic. XRD analysis revealed there is no significance difference in the crystalline structure after the plasma treatment. DSC shows a decrease in peak temperatures (Tp) after the treatment. Hot paste viscosities were observed to be decease from 692 to 591 BU was corresponded to decrease in peak temperature. The total polyphenolic content and reducing power was observed to be increased. The effects of plasma treatment on functional groups of polyphenols were observed by changes in absorption intensities using FTIR. This study demonstrates that the low temperature plasma treatmentis capable of improving the functional properties of basmati rice.

11.
Mater Sci Eng C Mater Biol Appl ; 62: 908-18, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26952498

RESUMO

The superior bulk properties (corrosion resistance, high strength to weight ratio, relatively low cost and easy processing) of hydrocarbon based polymers such as polypropylene (PP) have contributed significantly to the development of new biomedical applications such as artificial organs and cell scaffolds. However, low cell affinity is one of the main draw backs for PP due to its poor surface properties. In tissue engineering, physico-chemical surface properties such as hydrophilicity, polar functional groups, surface charge and morphology play a crucial role to enrich the cell proliferation and adhesion. In this present investigation TiOx based biocompatible coatings were developed on the surface of PP films via DC excited glow discharge plasma, using TiCl4/Ar+O2 gas mixture as a precursor. Various TiOx-based coatings are deposited on the surface of PP films as a function of discharge power. The changes in hydrophilicity of the TiOx/PP film surfaces were studied using contact angle analysis and surface energy calculations by Fowke's approximation. X-ray photo-electron spectroscopy (XPS) was used to investigate the surface chemical composition of TiOx/PP films. The surface morphology of the obtained TiOx/PP films was investigated by scanning electron and transmission electron microscopy (SEM &TEM). Moreover, the surface topography of the material was analyzed by atomic force microscopy (AFM). The cytocompatibility of the TiOx/PP films was investigated via in vitro analysis (cell viability, adhesion and cytotoxicity) using NIH3T3 (mouse embryonic fibroblast) cells. Furthermore the antibacterial activities of TiOx/PP films were also evaluated against two distinct bacterial models namely Gram positive Staphylococcus aureus (S.aureus) and Gram negative Escherichia coli DH5α. (E.coli) bacteria. XPS results clearly indicate the successful incorporation of TiOx and oxygen containing polar functional groups on the surface of plasma treated PP films. Moreover the surface of modified PP films exhibited nano structured morphology, as confirmed by SEM, TEM and AFM. The physico-chemical changes have improved the hydrophilicity of the PP films. The in-vitro analysis clearly confirms that the TiOx coated PP films performs as good as the standard tissue culture plates and also are unlikely to impact the bacterial cell viability.


Assuntos
Gases em Plasma , Polipropilenos/química , Titânio/química , Animais , Argônio/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Células NIH 3T3 , Oxigênio/química , Espectroscopia Fotoeletrônica , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
12.
Mater Sci Eng C Mater Biol Appl ; 36: 309-19, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24433917

RESUMO

In this paper, a thin transparent titania (TiO2) film was coated on the surface of flexible poly(ethylene terephthalate) (PET) film using the sol-gel method. The surface properties of the obtained TiO2/PET film were further improved by RF glow discharge oxygen plasma as a function of exposure time and discharge power. The changes in hydrophilicity of TiO2/PET films were analyzed by contact angle measurements and surface energy. The influence of plasma on the surface of the TiO2/PET films was analyzed by atomic force microscopy (AFM) as well as the change in chemical state and composition that were investigated by X-ray photo electron spectroscopy (XPS). The cytotoxicity of the TiO2/PET films was analyzed using human osteoblast cells and the bacterial eradication behaviors of TiO2/PET films were also evaluated against Staphylococcus bacteria. It was found that the surface roughness and incorporation of oxygen containing polar functional groups of the plasma treated TiO2/PET films increased substantially as compared to the untreated one. Moreover the increased concentration of Ti(3+) on the surface of plasma treated TiO2/PET films was due to the transformation of chemical states (Ti(4+)→Ti(3+)). These morphological and chemical changes are responsible for enhanced hydrophilicity of the TiO2/PET films. Furthermore, the plasma treated TiO2/PET film exhibited no citotoxicity against osteoblast cells and antibacterial activity against Staphylococcus bacteria which can find application in manufacturing of biomedical devices.


Assuntos
Tecnologia Biomédica/métodos , Oxigênio/química , Gases em Plasma/química , Polietilenoglicóis/farmacologia , Ondas de Rádio , Titânio/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas/efeitos dos fármacos , Microscopia de Força Atômica , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Espectroscopia Fotoeletrônica , Polietilenotereftalatos , Staphylococcus aureus/citologia , Staphylococcus aureus/efeitos dos fármacos , Tensão Superficial/efeitos dos fármacos , Termodinâmica
13.
Fitoterapia ; 79(1): 21-3, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17855019

RESUMO

The plant Phyllanthus reticulatus is claimed to have antidiabetic activity in tribal area. To validate the tribal claim, the petroleum ether and ethanolic extracts of leaves of the P. reticulatus were orally tested at 500 and 1000 mg/kg for hypoglycemic effect in alloxan induces diabetic mice. It shows antidiabetic activity at the dose of 1000 mg/kg. The phytochemical screening of the residues revealed the presence of terpenoids glycosides, protein, carbohydrates and absence of alkaloids and steroids.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Phyllanthus , Fitoterapia , Extratos Vegetais/uso terapêutico , Animais , Hipoglicemiantes/farmacologia , Camundongos , Extratos Vegetais/farmacologia , Folhas de Planta
15.
J Indian Med Assoc ; 101(10): 597-8, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15168977

RESUMO

A 63-year-old woman presented with a midline neck swelling which clinically appeared as goitre with bilateral cervical lymphadenopathy. Pre-operative investigations were suggestive of malignancy with lymph node metastasis for which a subtotal thyroidectomy with lymph node excision was done. But the histopathological examination of the operative specimen was reported as sinus histiocytosis of the thyroid and the cervical lymph nodes.


Assuntos
Histiocitose Sinusal/diagnóstico , Histiocitose Sinusal/cirurgia , Edema/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Pescoço
16.
Ultrason Sonochem ; 10(1): 45-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12457951

RESUMO

Arylhydrazones have been synthesized in excellent yields in short reaction times at ambient temperature conditions in the absence of any added catalyst by the reaction of phenylhydrazines with carbonyl compounds under ultrasonic irradiation.

17.
Artigo em Inglês | MEDLINE | ID: mdl-11563074

RESUMO

This article describes the purification and scale-up of ISIS 2302, a 20-mer phosphorothioate oligonucleotide by anion-exchange (AX) chromatography. The key operating parameters were optimized at gram scale and further scaled up to hundred gram. SOURCE 30Q, a high efficiency polymeric chromatographic media was used for both the small and large-scale work. High length-based purity and yield were maintained at scale-up. This purification is one of the largest demonstrations of AX purification of phosphorothioate oligonucleotide.


Assuntos
Oligodesoxirribonucleotídeos Antissenso/isolamento & purificação , Tecnologia Farmacêutica/métodos , Tionucleotídeos/isolamento & purificação , Cromatografia por Troca Iônica/métodos , Fármacos Gastrointestinais/isolamento & purificação , Temperatura Alta , Imunossupressores/isolamento & purificação , Oligonucleotídeos Fosforotioatos , Projetos Piloto , Solventes
18.
J Chromatogr A ; 923(1-2): 65-73, 2001 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-11510561

RESUMO

The development of efficient techniques for large-scale oligonucleotide purification is of great interest due to the increased demand for antisense oligonucleotides as therapeutics as well as their use for target validation and gene functionalization. This paper describes the use of anion-exchange displacement chromatography for the purification of 20-mer phosphorothioate oligonucleotide from its closely related impurities using low-molecular-mass amaranth as the displacer. Experiments were carried out to examine the effect of the feed load on the performance of the displacement chromatography. In contrast to prior work, displacement chromatography was successfully scaled-up to high column loadings while maintaining high purity and yields. Experiments carried out on a Source 15Q column indicated that crude oligonucleotide loading as high as 39.2 mg/ml of column were readily processed, resulting in product recovery of 86% and purity of 92%. These results demonstrate that anion-exchange displacement chromatography can indeed be employed for large-scale oligonucleotide separations at high column loading.


Assuntos
Cromatografia por Troca Iônica/métodos , Oligonucleotídeos/isolamento & purificação , Corante Amaranto , Ânions
19.
Chem Commun (Camb) ; (17): 1544-5, 2001 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-12240373

RESUMO

Heck reaction proceeds at ambient temperature (30 degrees C) with considerably enhanced reaction rate (1.5-3 h) through the formation of Pd-biscarbene complexes and stabilized clusters of zero-valent Pd nanoparticles in ionic liquids under ultrasonic irradiation.

20.
Biotechnol Prog ; 16(6): 1064-70, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11101335

RESUMO

High affinity, low molecular weight anionic displacers were successfully employed for the purification of antisense oligonucleotides. Several important structural characteristics were identified that contribute to the affinity of low molecular weight displacers to a hydrophilized polystyrene divinyl benzene anion exchanger. Sulfonic acid groups were found to possess higher affinity than carboxylic acid and phosphate functionalities, and nonspecific interactions (particularly hydrophobic interactions) were shown to play a major role in the retention process on this stationary phase material. Using this information, two high affinity, low molecular weight displacers were identified. These molecules are relatively inexpensive organic dyes that possess multiple sulfonic acid moieties, as well as aromatic functionalities, which increase nonspecific interactions with the stationary phase. These high affinity displacers, which can be readily detected, were then employed to displace several strongly retained antisense oligonucleotides that could not be displaced by previously established low molecular weight displacers. The displacement process resulted in very high purities of the antisense oligonucleotides. The results presented in this paper are significant in that they demonstrate that low molecular weight displacers for ion-exchange chromatography can possess equal to or greater affinities than their higher molecular weight counterparts, when nonspecific interactions with the stationary phase are exploited. In addition, the results illustrate the high resolutions possible with displacement chromatography and demonstrate an attractive technology for the process scale purification of oligonucleotides.


Assuntos
Oligonucleotídeos/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Peso Molecular
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