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1.
J Chromatogr A ; 1716: 464640, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38219626

RESUMO

In the last decade, the separation application based on aromatic stationary phases has been demonstrated in supercritical fluid chromatography (SFC). In this paper, four aromatic stationary phases involving aniline (S-aniline), 1-aminonaphthalene (S-1-ami-naph), 1-aminoanthracene (S-1-ami-anth) and 1-aminopyrene (S-1-ami-py) were synthesized based on full porous particles (FPP) silica, which were not end-capped for providing extra electrostatic interaction. Retention mechanism of these phases in SFC was investigated using a linear solvation energy relationship (LSER) model. The aromatic stationary phases with five positive parameters (a, b, s, e and d+) can provide hydrogen bonding, π-π, dipole-dipole and cation exchange interactions, which belong to the moderate polar phases. The LSER results obtained using routine test solutes demonstrated that the aforementioned interactions of four aromatic stationary phases were influenced by the type and bonding density of the ligand, but to a certain extent. Furthermore, the LSER data verified that the S-1-ami-anth column based on full porous particles silica had higher cation exchange capacity (d+ value), compared to the commercialized 1-AA column (based on the ethylene-bridged hybrid particles). The relationship between the d+ value and SFC additive was quantitatively proved so as to regulate electrostatic interaction reasonably. This value was greatly increased by phosphoric acid, slightly increased by trifluoroacetic acid and formic acid, but significantly reduced by ammonium formate and diethylamine. Taking the S-1-ami-naph column as an example, better peek shape of the flavonoids was obtained after the addition of 0.1 % phosphoric acid in MeOH while isoquinoline alkaloids were eluted successfully within 11 min after adding 0.1 % diethylamine in MeOH. Combined with the unique π-π interaction and controllable electrostatic interaction, the aromatic stationary phases in this study have been proven to have expandable application potential in SFC separation.


Assuntos
Cromatografia com Fluido Supercrítico , Ácidos Fosfóricos , Cromatografia com Fluido Supercrítico/métodos , Dióxido de Silício/química , Cátions , Compostos de Anilina , Dietilaminas
2.
Molecules ; 28(16)2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37630289

RESUMO

New hydroxy-methylenebisphosphonic derivatives were prepared with different P-functions. The outcome of the reaction of α-oxophosphonates (YC(O)P(O)(OR)2) and dialkyl phosphites or diarylphosphine oxides depended on the Y substituent of the oxo-compound, the nature of the P-reagent and the amount of the diethylamine catalyst. Starting from dimethyl α-oxoethylphosphonate, in the presence of 5% of diethylamine, the corresponding Pudovik adduct was the single product. While using 40% of the catalyst, the rearranged species with the >P(O)-O-CH-P(O)< skeleton was the exclusive component. A similar reaction of α-oxobenzylphosphonate followed the rearrangement protocol. X-ray crystallography revealed not only the spatial structures of the three products, but also an intricate pattern evolving from the interplay of slight chemical differences, solvent inclusion and disorder as well as H-bridge patterns, which invite further investigation. In vitro activity of the compounds was assessed on different tumor cell cultures using end-point-type cell tetrazolium-based measurements. These structure-activity studies revealed a cytostatic effect for four rearranged derivatives containing aromatic units. One of them had a pronounced effect on MDA-MB 231 and Ebc-1 cells, showing IC50 = 37.8 and 25.9 µM, respectively.


Assuntos
Compostos Radiofarmacêuticos , Raios X , Radiografia , Sais de Tetrazólio , Dietilaminas
3.
Int J Biol Macromol ; 233: 123547, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36740123

RESUMO

Lignin-based hybrid fillers are of increasing importance with regards to the valorization of low-value biomass and the requirement of sustainability in rubber industry, however, a facile lignin modification approach tuning the supramolecular interactions to favor the assembly of the hybrids is in demand. This study aimed to design a lignin/SiO2 nano-hybrid via an in-situ assembly of diethylamine grafted lignin (DL) and SiO2, and investigate its reinforcing effect on natural rubber (NR). DL was prepared through Mannich modification of lignin, and the grafted diethylamine can be clearly identified by FTIR, NMR and elemental analysis. The resultant hybrid (DLSi) displays as homogeneous nanospheres with well integrated DL and SiO2 components as shown in the TEM images, and the hybrid (DLSi1) prepared with weight ratio of DL/SiO2 = 1/2 shows a minimum particle size of 101.8 nm and significantly reduced polarity. Compared to the reference composite filled only with carbon black (CB), NR composites filled with DLSi/CB of 10/40 phr shows comparable mechanical properties and reduced rolling resistance, which is due to the low particle size, homogenous dispersion and strong rubber-filler interfacial affinity. Such remarkable performance suggests that the DLSi hybrid can be a promising versatile biobased filler for the application in gasoline-saving "green" tires.


Assuntos
Lignina , Borracha , Aminação , Dióxido de Silício , Dietilaminas , Excipientes
4.
Pharm Res ; 39(10): 2515-2527, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36002613

RESUMO

PURPOSE: Treating chronic wounds is a significant clinical challenge, and a topical product would be ideal for pain management. Poloxamer 407, a thermosensitive polymer, would allow an analgesic drug to be topically applied to a wound as a liquid that transitions to a gel at physiologic temperature. Using diclofenac as a model analgesic drug, our goal was to determine effects of salt form on poloxamer gelation and drug delivery from poloxamer gels applied to excised skin with impaired barrier function. METHODS: Gelation properties of 17% and 20% poloxamer gels loaded with 0.4 to 1.7% diclofenac sodium, potassium, epolamine, or diethylamine were evaluated rheologically. Drug release and delivery were quantified using cellulose membranes, porcine skin, and tape-stripped porcine skin. RESULTS: Poloxamer gelation temperature increased with higher diclofenac concentration, regardless of salt form; the magnitude of increase varied in the following order: sodium>potassium>diethylamine>epolamine. Gelation temperature differences resulting from the various counterions generally matched previously observed trends of ion-specific effects on macromolecule solubility (the Hofmeister series). Despite changes in gelation behavior, we observed minimal corresponding effects on drug release or delivery. There were no significant differences in diclofenac released or delivered through intact porcine skin over 48 h. However, in studies with impaired (tape-stripped) skin, diclofenac delivery was slowest overall with the epolamine salt. CONCLUSION: Varying the salt form of a model analgesic drug can impact gelation and drug delivery characteristics of poloxamer systems. Further study of the mechanisms of these changes will be important for continued development of topical poloxamer products for clinical wound care.


Assuntos
Diclofenaco , Poloxâmero , Animais , Celulose , Dietilaminas , Géis , Potássio , Sódio , Cloreto de Sódio , Suínos , Temperatura
5.
Org Biomol Chem ; 20(34): 6750-6754, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35938985

RESUMO

An original and facile method for the generation of ß-naphtha-1-thioquinones using DAST and 2-naphthols has been developed. A series of dehydro-2-naphthol-1-sulphides or naphtha-oxathiane derivatives were synthesized by in situ Diels-Alder cycloaddition reactions of ß-naphtha-1-thioquinone with itself or various alkenes.


Assuntos
Naftóis , Alcanos , Reação de Cicloadição , Dietilaminas , Flúor , Solventes , Estereoisomerismo
6.
Trials ; 23(1): 555, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35804406

RESUMO

BACKGROUND: Both massage and topically administered NSAIDs are safe and effective treatments for knee osteoarthritis (KOA); however, different massage technique sects in China caused assessment difficulties for the treatment of KOA. In order to standardize the massage techniques and procedures, we organized multi-disciplinary experts in China to acquire an evidence-based traditional Chinese medicine massage treatment of knee osteoarthritis. The purposes of this study will be to provide clinicians a complementary and alternative therapy for patients and to evaluate the efficacy and safety of evidence-based traditional Chinese medicine massage treatment of KOA compared to External Diclofenac Diethylamine Emulgel. METHODS AND DESIGN: A randomized controlled trial in which 300 participants diagnosed with KOA will be recruited and randomly allocated to either the experimental group or the control group in a ratio of 2:1. Two hundred participants will receive evidence-based traditional Chinese medicine massage 2 sessions per week for 10 weeks as the experimental group, and 100 participants will receive External Diclofenac Diethylamine Emulgel 3-4 times per day for 10 weeks as the control group. The patients in the two groups will receive follow-up at two time points at 5 weeks and 10 weeks from the beginning of treatment, respectively. The MRI scans and X-ray will be performed at baseline and at the end of the intervention. The primary outcome will be the changes in the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Secondary outcomes will be measured by the PRO scale for knee osteoarthritis based on the concept of traditional Chinese medicine (Chinese scale for knee osteoarthritis (CSKO)), X-ray evaluation, and MRI scan evaluation. The data of WOMAC and CSKO will be analyzed at the baseline, 5 weeks, and 10 weeks from the beginning of treatment. The data from MRI scans and X-rays will be analyzed at baseline and at the end of the intervention. The significance level sets as 5%. The safety of interventions will be evaluated after each treatment session. DISCUSSION: This study will provide clinicians with much-needed knowledge for the treatment of KOA through a controlled trial. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1800014400 . Registered on 10 January 2018.


Assuntos
Osteoartrite do Joelho , Diclofenaco/análogos & derivados , Dietilaminas/uso terapêutico , Humanos , Massagem , Medicina Tradicional Chinesa/efeitos adversos , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/tratamento farmacológico , Resultado do Tratamento
7.
Wilderness Environ Med ; 33(3): 311-317, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35843856

RESUMO

INTRODUCTION: Drones can transmit live video and geographic coordinates during the planning stages for search and rescue operations and the operations themselves. There are few simulation studies in which drones provided rescue support. However, the literature does not contain any simulation studies involving the use of drones to locate lost "victims" represented by dummies in rivers. We developed a simulation model to compare the first visual contact times for drone-assisted search techniques (DAST) and classic search techniques (CST). METHODS: In this prospective experimental simulation study, we used both DAST and CST to perform a series of river searches for unconscious victims (represented by dummies). We calculated the first visual contact times, total scanned area, scanned area per minute, flight-walking distances, and flight-walking speeds and compared the results between both groups. The data are presented as mean±SD. RESULTS: We performed 20 search and rescue operations, 10 with the CST and 10 with the DAST. The time to reach the victim was 823±177 s using CST and 80±14 s using DAST. The area scanned by unit time was 3091±54 m2·min-1 using CST and 22,640±1622 m2·min-1 using DAST. CONCLUSIONS: The drone-assisted search technique located a simulated victim drifting in a river faster than the classic search technique. The use of drones in search and rescue operations could improve the time to find victims.


Assuntos
Rios , Dispositivos Aéreos não Tripulados , Dietilaminas , Flúor , Estudos Prospectivos
8.
Org Biomol Chem ; 20(33): 6558-6561, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-35900043

RESUMO

A diethylaminosulfur trifluoride (DAST)-mediated ring-opening reaction of cyclopropyl silyl ethers in nitriles produced allylic amides in moderate to good yields (up to 87%). Time course studies using ReactIR and O-isotopic labeling mechanistic studies suggested that the present reaction occurs via a Ritter-type process, leading to the formation of allylic amides.


Assuntos
Amidas , Éteres , Dietilaminas , Flúor , Nitrilas
9.
Int J Mol Sci ; 23(7)2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35408806

RESUMO

Fluorine represents a privileged building block in pharmaceutical chemistry. Diethylaminosulfur-trifluoride (DAST) is a reagent commonly used for replacement of alcoholic hydroxyl groups with fluorine and is also known to catalyze water elimination and cyclic Beckmann-rearrangement type reactions. In this work we aimed to use DAST for diversity-oriented semisynthetic transformation of natural products bearing multiple hydroxyl groups to prepare new bioactive compounds. Four ecdysteroids, including a new constituent of Cyanotis arachnoidea, were selected as starting materials for DAST-catalyzed transformations. The newly prepared compounds represented combinations of various structural changes DAST was known to catalyze, and a unique cyclopropane ring closure that was found for the first time. Several compounds demonstrated in vitro antitumor properties. A new 17-N-acetylecdysteroid (13) exerted potent antiproliferative activity and no cytotoxicity on drug susceptible and multi-drug resistant mouse T-cell lymphoma cells. Further, compound 13 acted in significant synergism with doxorubicin without detectable direct ABCB1 inhibition. Our results demonstrate that DAST is a versatile tool for diversity-oriented synthesis to expand chemical space towards new bioactive compounds.


Assuntos
Ecdisteroides , Flúor , Animais , Catálise , Dietilaminas/química , Ecdisteroides/química , Flúor/química , Camundongos
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 274: 121065, 2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35245801

RESUMO

Femtosecond time-resolved photoelectron spectroscopy was employed to investigate the ultrafast non-adiabatic dynamics of diethylamine (DEA). Following the direct excitations of the two main conformational structures (i.e., TT and TG) of DEA to the 3p Rydberg states at 200 nm, DEA undergoes internal conversion to the 3s state with ∼68 fs, which is similar to previously relaxation pathways of several secondary and tertiary amines. Subsequent dynamics on the 3s Rydberg state evolves along the NH stretching coordinate and is then accompanied by the breaking of the NH bond in about 120 fs, rather than the cleavage of the NC, or CC bonds as well as the conformational transformations between the TT and TG conformers on the 3s states. Theoretically, we reveal the pre-dissociative nσ* character evolving along the NH stretching coordinate within the 3s state as DEA dissociates to yield H atom products. As contrasted to the well-known conformational NC bond rotation motions in systems such as tertiary amines, the non-adiabatic relaxation of the 3s state of DEA is predominantly characterized by the NH bond dissociation process.


Assuntos
Aminas , Dietilaminas , Conformação Molecular , Movimento (Física) , Espectroscopia Fotoeletrônica
11.
J Phys Chem B ; 125(39): 11005-11016, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34570507

RESUMO

The study highlights the effect of acid- and base-rich conditions on the proton dynamics of diethylmethylammonium poly[4-styrenesulfonyl(trifluoromethylsulfonyl)imide, [DEMA][PSTFSI], a polymerized protic ionic liquid designed as a polymer electrolyte for nonhumidified polymer electrolyte membrane fuel cells. Different proportions of triflic acid (HTf) and diethylmethylamine (DEMA) were added to the pristine polymer. The thermal analysis of the mixtures revealed that the addition of the base increases the glassy/amorphous nature of the polymer; however, HTf plasticizes the polymer and lowers the Tg value, so that it falls outside of the differential scanning calorimetry-studied temperature range. 50 mol % doping of the HTf contents increases the conductivity upto 0.952 mS cm-1, and 50 mol % DEMA mixture has a conductivity of 0.169 mS cm-1 at 100 °C. Vogel-Tamman-Fulcher fitting of the ionic conductivities of the doped systems suggested that the ionic conductivities are completely decoupled from segmental motion of the polymer. A combination of Fourier transform infrared and static NMR studies demonstrated that HTf-added polymer composites show conduction via Grotthuss and vehicular mechanisms, while DEMA-added polymer composites show predominantly a Grotthuss mechanism by developing the aggregates of proton and added base.


Assuntos
Imidas , Líquidos Iônicos , Dietilaminas , Mesilatos , Prótons
12.
PLoS One ; 16(8): e0256016, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34383828

RESUMO

Mitochondria participate in multiple functions in eukaryotic cells. Although disruption of mitochondrial function has been associated with energetic deregulation in cancer, the chronological changes in mitochondria during cancer development remain unclear. With the aim to assess the role of mitochondria throughout cancer development, we analyzed samples chronologically obtained from induced hepatocellular carcinoma (HCC) in rats. In our analyses, we integrated mitochondrial proteomic data, mitochondrial metabolomic data and nuclear genome transcriptomic data. We used pathway over-representation and weighted gene co-expression network analysis (WGCNA) to integrate expression profiles of genes, miRNAs, proteins and metabolite levels throughout HCC development. Our results show that mitochondria are dynamic organelles presenting specific modifications in different stages of HCC development. We also found that mitochondrial proteomic profiles from tissues adjacent to nodules or tumor are determined more by the stage of HCC development than by tissue type, and we evaluated two models to predict HCC stage of the samples using proteomic profiles. Finally, we propose an omics integration pipeline to massively identify molecular features that could be further evaluated as key regulators, biomarkers or therapeutic targets. As an example, we show a group of miRNAs and transcription factors as candidates, responsible for mitochondrial metabolic modification in HCC.


Assuntos
Carcinoma Hepatocelular/patologia , Dietilaminas/toxicidade , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Metaboloma , Mitocôndrias/metabolismo , Proteoma/metabolismo , Transcriptoma , Animais , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Mitocôndrias/efeitos dos fármacos , Proteoma/análise , Ratos , Ratos Endogâmicos F344
14.
J Pharm Biomed Anal ; 203: 114214, 2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34153937

RESUMO

Methionine (MET) is combined with paracetamol (PAR) in a pain relief soft capsule in order to prevent the haematologic damage of paracetamol. A hydrophillic liquid chromatographic (HILIC) method was developed for simultaneous determination of PAR and MET in the combined formulation. Various analytical conditions were investigated, and the final method was chosen using silica column (150 × 4,6 mm; 5 µm), mobile phase of acetonitrile - aqueous solution of 10 mM formic acid 5 mM diethylamine (60:40, v/v), UV detection at 254 nm for PAR and 210 nm for MET. The method was validated according to ICH guidelines in terms of selectivity, linearity, accuracy, precision and robustness. The method was successfully applied for quantitation of both compounds in soft capsule preparations bought from the market. Notably, in this study, a novel approach was proposed to improve peak shape of amino acid - a problem often observed in HILIC. The addition of diethylamine to mobile phase shortened the retention time of MET and significantly improved peak shape on both silica and cyano columns, due to electrostatic interaction competition and silanol end-capping effect. The result of this research demonstrated the advantages of HILIC in simultaneous analysis of a polar compound amino acid, especially in combination with a less polar substance. The use of diethylamine as a mobile phase modifier to enhance peak shape is a new suggestion that can be used in further studies on amino acid analysis by HILIC.


Assuntos
Acetaminofen , Metionina , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Dietilaminas , Interações Hidrofóbicas e Hidrofílicas
15.
Anal Methods ; 13(19): 2189-2195, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33899837

RESUMO

In this study, based on silica hollow sphere photonic crystals (SHSPCs), a simple and selective fluorescence sensor for high-performance diethylamine detection was developed. The sensor does not involve complicated integration of arrays or tedious synthetic work. During the detection, the SHSPCs could significantly enhance the fluorescence intensity of rhodamine 6G (Rh6G), and meanwhile, adsorb some Rh6G on their surface. Due to the competitive adsorption, diethylamine could free the Rh6G which was adsorbed on the surface of the SHSPCs, thus enhancing the fluorescence emission intensity with the increase of Rh6G concentration. The second enhancement of the fluorescence emission enabled the selective detection of diethylamine. It is remarkable that a simple and readily available dye (Rh6G) facilitates the efficient detection of diethylamine. Moreover, the sensor has good interference immunity, stability and reusability.


Assuntos
Fótons , Dióxido de Silício , Adsorção , Dietilaminas , Fluorescência
16.
Comb Chem High Throughput Screen ; 24(4): 485-489, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32691709

RESUMO

In the present study, SAPO-34 particles were synthesized using hydrothermal (HT) and dry gel (DG) conversion methods in the presence of diethyl amine (DEA) as an organic structure directing agent (SDA). Carbon nanotubes (CNT) were used as a hard template in the synthesis procedure to introduce transport pores into the structures of the synthesized samples. The synthesized samples were characterized with different methods to reveal the effects of synthesis method and using hard template on their structure and catalytic performance in methanol to olefin reaction (MTO). DG conversion method results in smaller particle size in comparison with hydrothermal method, resulting in enhancing catalytic performance. On the other side, using CNT in the synthesis procedure with DG method results in more reduction in particle size and formation of hierarchical structure, which drastically improves catalytic performance.


Assuntos
Alcenos/síntese química , Metanol/química , Zeolitas/química , Catálise , Dietilaminas/química , Cinética , Nanotubos de Carbono/química , Tamanho da Partícula , Porosidade
17.
Drug Dev Ind Pharm ; 46(10): 1705-1715, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32892653

RESUMO

The objective of this study was to develop novel topical drug delivery systems of the nonsteroidal anti-inflammatory drug diclofenac diethylamine (DDEA). Toward this objective, DDEA was loaded into two nanosystems, the oil in water (O/W) nanoemulsion (DDEA-NE) and the gold nanorods (GNR) that were conjugated to DDEA, forming DDEA-GNR. The DDEA-NE and DDEA-GNR were characterized in terms of particle size, zeta potential, morphology, thermodynamic stability, DDEA loading efficiency, and UV-Vis spectroscopy. These nanosystems were then incorporated into the biphasic gel-based formulations (bigels) for topical delivery. The rheological characterization and release studies of the DDEA NE- and DDEA GNR-incorporated bigels were performed and compared to those of DDEA traditional bigel. DDEA-NE exhibited a droplet size 15.2 ± 1.5 nm and zeta potential -0.37 ± 0.06 mV. The particle size of GNR was approximately 66 nm × 17 nm with an aspect ratio of approximately 3.8. The bigels showed composition-dependent viscoelastic properties, which in turn play a vital role in determining the rate and mechanism of DDEA release from the bigels. Bigels showed a controlled-release pattern where 61.6, 91.7, and 50.0% of the drug was released from DDEA traditional bigel, DDEA NE-incorporated bigel, and DDEA GNR-incorporated bigel, respectively, after 24 h. The ex vivo permeation studies showed that the amount of DDEA permeated through excised skin was relatively low, between 2.7% and 18.2%. The results suggested that the incorporation of the nanosystems NE and GNR into bigels can potentially improve the topical delivery of DDEA.


Assuntos
Diclofenaco/análogos & derivados , Dietilaminas/química , Sistemas de Liberação de Medicamentos , Diclofenaco/química , Tamanho da Partícula , Reologia
18.
J Sep Sci ; 43(13): 2589-2593, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32297397

RESUMO

Ramosetron is an enantiopure active pharmaceutical ingredient marketed in Japan since 1996 and later in a few Southeast Asian countries predominantly as an antiemetic for patients receiving chemotherapy. In this study, a simple and rapid high-performance liquid chromoatography method for the separation of ramosetron and its related enantiomeric impurity by using hydrophilic interaction liquid chromatography mode is presented. Chiral resolution was performed on an analytical column (100 mm × 4.6 mm id) packed with 3 µm particles of cellulose-based Chiralpak IC-3 chiral stationary phase. Using a mobile phase containing acetonitrile-water-diethylamine (100:10:0.1, v/v/v) and setting the column temperature at 35°C, the resolution value was 7.35. At a flow rate of 1 mL/min, the enantioseparation was completed within 5 min. The proposed method was partially validated and it has proven to be sensitive with limit of detection and limit of quantitation of the (S)-enantiomer impurity of 44.5 and 133.6 ng/mL.


Assuntos
Benzimidazóis/isolamento & purificação , Celulose/química , Acetonitrilas/química , Benzimidazóis/química , Cromatografia Líquida de Alta Pressão , Dietilaminas/química , Halogenação , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Estereoisomerismo , Água/química
19.
J Chromatogr A ; 1621: 461048, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32204879

RESUMO

The impact of eluent components added to improve separation performance in supercritical fluid chromatography was systematically, and fundamentally, investigated. The model system comprised basic pharmaceuticals as solutes and eluents containing an amine (i.e., triethylamine, diethylamine, or isopropylamine) as additive with MeOH as the co-solvent. First, an analytical-scale study was performed, systematically investigating the impact of the additives/co-solvent on solute peak shapes and retentions, using a design of experiments approach; here, the total additive concentration in the eluent ranged between 0.021 and 0.105 % (v/v) and the MeOH fraction in the eluent between 16 and 26 % (v/v). The co-solvent fraction was found to be the most efficient tool for adjusting retentions, whereas the additive fraction was the prime tool for improving column efficiency and peak analytical performance. Next, the impacts of the amine additives on the shapes of the so-called overloaded solute elution profiles were investigated. Two principal types of preparative peak deformations appeared and were investigated in depth, analyzed using computer simulation with mechanistic modeling. The first type of deformation was due to the solute eluting too close to the additive perturbation peak, resulting in severe peak deformation caused by co-elution. The second type of deformation was also due to additive-solute interactions, but here the amine additives acted as kosmotropic agents, promoting the multilayer adsorption to the stationary phase of solutes with bulkier aryl groups.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Adsorção , Simulação por Computador , Dietilaminas/química , Etilaminas/química , Propilaminas/química , Solventes/química
20.
Bioorg Med Chem Lett ; 30(6): 126998, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-32014383

RESUMO

[Thiocarbonyl-11C]disulfiram ([11C]DSF) was synthesized via iodine oxidation of [11C]diethylcarbamodithioic acid ([11C]DETC), which was prepared from [11C]carbon disulfide and diethylamine. The decay-corrected isolated radiochemical yield (RCY) of [11C]DSF was greatly affected by the addition of unlabeled carbon disulfide. In the presence of carbon disulfide, the RCY was increased up to 22% with low molar activity (Am, 0.27 GBq/µmol). On the other hand, [11C]DSF was obtained in 0.4% RCY with a high Am value (95 GBq/µmol) in the absence of carbon disulfide. The radiochemical purity of [11C]DSF was always >98%. The first PET study on [11C]DSF was performed in mice. A high uptake of radioactivity was observed in the liver, kidneys, and gallbladder. The uptake level and distribution pattern in mice were not significantly affected by the Am value of the [11C]DSF sample used. In vivo metabolite analysis showed the rapid decomposition of [11C]DSF in mouse plasma.


Assuntos
Radioisótopos de Carbono/química , Dissulfiram/síntese química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/síntese química , Animais , Dissulfeto de Carbono/química , Complexos de Coordenação/química , Dietilaminas/química , Dissulfiram/metabolismo , Ditiocarb/química , Vesícula Biliar/metabolismo , Iodo/química , Rim/metabolismo , Ligantes , Fígado/metabolismo , Camundongos , Oxirredução , Compostos Radiofarmacêuticos/metabolismo , Distribuição Tecidual
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