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1.
Environ Technol ; : 1-22, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38471075

RESUMO

Forward Osmosis (FO), a membrane desalination technology and Capacitive Deionization (CDI), an electrically operated desalination technology, are numerically integrated utilizing four different configurations for the high-water recovery rate and ultrapure water production from brackish water resource. To minimize the wastewater rejection, the CDI desorption stream is continuously fed to the FO unit, efficiently recovering the remaining freshwater. To produce ultrapure water, freshwater stream obtained from FO is provided to the CDI cell, which adsorbs the remaining dissolved solute particles. These two configurations serve the purpose of both industrial as well as domestic water supply requirements. Continuing this concept, the formation of the other two configurations allows us to obtain fresh water and ultrapure water simultaneously and up to a 90% freshwater recovery rate for the areas with inadequate supply. The performance parameters to assess the integration are the Water Recovery Rate (WRR) and Specific Energy Consumption (SEC). The first configuration (CDI-FO), proposed for a high freshwater recovery rate, resulted in 79.33% WRR with an SEC of 0.689kWh/m3. While, for the second configuration (FO-CDI), 34.25% water was recovered as 2.87 ppm ultrapure water along with 34.25% freshwater. The third proposed configuration (CDI-FO-CDI) had a WRR of 79.33%, 14.67% of which was recovered as ultrapure water of concentration 2.86 ppm. The fourth configuration (CDI-FO-FO) developed for high water recovery, removed the maximum of water from the feed stream with a WRR of 91.33% and remained energy-efficient, consuming an SEC of 0.908kWh/m3.

2.
Front Artif Intell ; 6: 1248977, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37780837

RESUMO

During Basic screening, it is challenging, if not impossible to detect breast cancer especially in the earliest stage of tumor development. However, measuring the electrical impedance of biological tissue can detect abnormalities even before being palpable. Thus, we used impedance characteristics data of various breast tissue to develop a breast cancer screening tool guided and augmented by a deep learning (DL). A DL algorithm was trained to ideally classify six classes of breast cancer based on electrical impedance characteristics data of the breast tissue. The tool correctly predicted breast cancer in data of patients whose breast tissue impedance was reported to have been measured when other methods detected no anomaly in the tissue. Furthermore, a DL-based approach using Long Short-Term Memory (LSTM) effectively classified breast tissue with an accuracy of 96.67%. Thus, the DL algorithm and method we developed accurately augmented breast tissue classification using electrical impedance and enhanced the ability to detect and differentiate cancerous tissue in very early stages. However, more data and pre-clinical is required to improve the accuracy of this early breast cancer detection and differentiation tool.

3.
Luminescence ; 38(6): 680-691, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36995153

RESUMO

The online photoreaction of the rose bengal photosensitized luminol-copper (II) chemiluminescence (CL) system was used for the determination of ß-nicotinamide adenine dinucleotide (NADH) and ethanol (EtOH) in pharmaceutical formulations combined with a flow injection technique. NADH can significantly enhance the CL emission of the reaction. For EtOH, alcohol dehydrogenase in soluble form was utilized in the presence of nicotinamide adenine dinucleotide resulting in NADH production. The limit of detection (3σ blank, 𝑛 = 3) of 4.0 × 10-8 and 2.17 × 10-5  M, and linear range 1.3 × 10-7 to 2.5 × 10-5  M (R2  = 0.9998, n = 6) and 0.11-2.17 × 10-3  M (R2  = 0.9996, n = 6) were obtained for NADH and EtOH respectively. The injection rate was 100 h-1 with a relative standard deviation (n = 3) of 1.5-4.8% in the range studied for both analytes. The procedure was satisfactorily applied to pharmaceutical formulations with recoveries in the range 91.6 ± 3.0% to 110 ± 2.0% for NADH and 88 ± 3.0% to 95.4 ± 4.0% for EtOH. The results obtained were very consistent and did not differ considerably from the reported approaches at a 95% confidence limit. The possible mechanism of the CL reaction is also explained briefly.


Assuntos
Luminol , NAD , Cobre , Rosa Bengala , Luminescência , Medições Luminescentes/métodos , Análise de Injeção de Fluxo/métodos , Preparações Farmacêuticas
4.
Luminescence ; 37(7): 1126-1134, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35470954

RESUMO

A chemiluminescence (CL) method based on rhodamine 6G (R6G)-diperiodatoargentate(III) (silver(III) complex) reaction in acid solution is reported for the determination of lansoprazole (LNP) combined with a flow injection (FI) technique. The most likely mechanism for CL reaction was elucidated considering reported data, spectrophotometric and spectrofluorimetric studies. The weak CL reaction between R6G and silver(III) complex could be magnanimously increased in the presence of LNP with a limit of detection (LOD) of 0.002 mg L-1 (S/N = 3), a linear range of 0.01 to 10 mg L-1 (R2 = 0.9997, n = 7), a relative standard deviation (RSD) of 1.2 to 3.2% (n = 4) and an injection throughput of 140 h-1 . No interference activity of commonly found excipients in LNP was detected. After LNP extraction from pharmaceutical samples, the recovery rate ranging from 93 to 110% (RSD, 1.4-3.3%, n = 4) was calculated. The results of the proposed flow CL method were assessed with a spectrophotometric approach applying paired Student's t-test and the calculated value (0.178) was lower than the distributed value (2.20) at a 95% confidence limit.


Assuntos
Análise de Injeção de Fluxo , Lansoprazol , Medições Luminescentes , Preparações Farmacêuticas , Complexos de Coordenação , Análise de Injeção de Fluxo/métodos , Lansoprazol/análise , Medições Luminescentes/métodos , Preparações Farmacêuticas/análise , Rodaminas , Prata
5.
Metallomics ; 13(6)2021 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-34021581

RESUMO

Pt-ttpy (tolyl terpyridin-Pt complex) covalently binds to G-quadruplex (G4) structures in vitro and to telomeres in cellulo via its Pt moiety. Here, we identified its targets in the human genome, in comparison to Pt-tpy, its derivative without G4 affinity, and cisplatin. Pt-ttpy, but not Pt-tpy, induces the release of the shelterin protein TRF2 from telomeres concomitantly to the formation of DNA damage foci at telomeres but also at other chromosomal locations. γ-H2AX chromatin immunoprecipitation (ChIP-seq) after treatment with Pt-ttpy or cisplatin revealed accumulation in G- and A-rich tandemly repeated sequences, but not particularly in potential G4 forming sequences. Collectively, Pt-ttpy presents dual targeting efficiency on DNA, by inducing telomere dysfunction and genomic DNA damage at specific loci.


Assuntos
Cisplatino/farmacologia , Dano ao DNA , Quadruplex G , Compostos Organoplatínicos/farmacologia , Neoplasias Ovarianas/patologia , Telômero/efeitos dos fármacos , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Antineoplásicos/farmacologia , Apoptose , Proliferação de Células , Feminino , Humanos , Compostos Organoplatínicos/química , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Proteína 2 de Ligação a Repetições Teloméricas/genética , Células Tumorais Cultivadas
6.
Luminescence ; 36(3): 674-683, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33179404

RESUMO

A simple and sensitive flow injection-chemiluminescence (FI-CL) method was developed for determination of cetirizine dihydrochloride (CTZH) in pharmaceuticals. The method is primarily based on the enhancement effect of CTZH on the tris(2,2'-bipyridyl)ruthenium (II)-diperiodatoargentate (III) ([Ru(bpy)3 ]2+ -Ag(III) complex) CL system in an acidic medium. The optimum investigated variables of the CL reaction were: [Ru(bpy)3 ]2+ , 50 × 10-6 mol/L; sulfuric acid, 1.0 × 10-3 mol/L; Ag(III) complex, 100 × 10-6 mol/L; potassium hydroxide, 1.0 × 10-3 mol/L; flow rate, 3.0 ml/min and sample loop volume, 300 µl. The detection and quantification limits were 2.0 × 10-4 and 5.0 × 10-4 mg/L (S/N of 3 and 10) respectively with a linear calibration range of 5.0 × 10-4 to 7.5 mg/L (R2 = 0.9999, n = 11), injection throughput of 110/h and the relative standard deviations of 1.5-3.5% over the range studied. The methodology was successfully applied to determine CTZH in different pharmaceutical samples and validated with a high-performance liquid chromatography method, and resulted in the recovery of 94.6-108.6%. The probable CL reaction mechanism is described in brief.


Assuntos
Preparações Farmacêuticas , Rutênio , 2,2'-Dipiridil , Cetirizina , Análise de Injeção de Fluxo , Luminescência , Medições Luminescentes , Prata
7.
Nutrire ; 46(1): 10, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-38624825

RESUMO

Aim: The aim of this study was to describe dietary practices of adult Egyptians, estimate changes in their body mass index (BMI), and identify possible determinants of such changes before and during the COVID-19 lockdown. Subject and methods: A cross-sectional web-based survey was conducted during the nationwide COVID-19 partial lockdown. Data were obtained from 430 Egyptian adults regarding their personal and socio-demographic characteristics, routine daily physical activities, dietary patterns, practices related to food purchase and food handling, and weight and BMI before and during the lockdown using an online web-based questionnaire. Results: The number of daily meals and daily snacks significantly increased during the lockdown. Moreover, the consumption of all types of snacks increased, except for chocolate and sweets, whose consumption decreased. Eating of fast food decreased, whereas the number of individuals practicing indoor physical activities increased during the lockdown. During the lockdown, no significant changes in the mean BMI were observed. The mean weekly consumption of starch, meat, milk, fat, and free foods decreased, whereas the mean weekly consumption of fruits and vegetables increased. Food handling practices improved during the lockdown. Based on the results of the linear regression analysis, age, the number of daily meals, practicing of physical activities during lockdown, and mean weekly consumption of meat were the independent predictors of BMI during the lockdown. Conclusion: During the lockdown, no significant changes in the BMI of adult Egyptians were observed, whereas dietary practices and food handling practices changed.

8.
ACS Omega ; 5(24): 14656-14668, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32596603

RESUMO

A bentonite/Zeolite-P (BE/ZP) composite was synthesized by controlled alkaline hydrothermal treatment of bentonite at 150 °C for 4 h for effective sequestration of phosphate and ammonium pollutants. The composite is of 512 m2/g surface area, 387 meq/100 g ion-exchange capacity, and 5.8 nm average pore diameter. The experimental investigation reflected the strong effect of the pH value in directing the uptake behavior and the best results were attained at pH 6. The kinetic properties showed an excellent agreement for phosphate and ammonium adsorption results with the pseudo-second-order model showing equilibrium intervals of 600 and 360 min, respectively, and maximum experimental capacities of 170 and 155 mg/g, respectively. Additionally, their equilibrium modeling confirmed excellent fitness with the Langmuir hypothesis, signifying homogeneous and monolayer uptake processes with a theoretical q max of 179.4 and 166 mg/g for phosphate and ammonium, respectively. Moreover, the calculated Gaussian adsorption energies of phosphate (0.8 kJ/mol) and ammonium (0.72 kJ/mol) suggested physisorption for them with mechanisms close to the zeolitic ion-exchange process or the coulumbic attractive forces. This was supported by the assessed thermodynamic parameters which also suggested spontaneous uptake by endothermic reaction for phosphate and exothermic reaction for ammonium. The BE/ZP composite is of excellent reusability and used for eight recyclability runs achieving removal percentages of 61.5 and 74.5% for phosphate and ammonium, respectively, in run 8. Finally, the composite was applied in the purification of sewage water and groundwater, achieving complete removal for phosphate from sewage water and ammonium from groundwater and reduction of the ammonium ions in the sewage water to 2.3 mg/L.

9.
J Food Biochem ; 44(8): e13313, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32497284

RESUMO

The present study was to investigate the effective role of renewable sources of Ca+2 from eggshell (ES) with different doses to restrict obesity disorders. Rats were classified as follows, G1 : normal diet for 26 weeks; G2 : high-fat diet (HFD) for 26 weeks; G3 , G4 , and G5 were supplemented with HFD for 16 weeks and treated with 7.2 g Ca+2 ES/Kg rat chow, 18 g Ca+2 ES/Kg rat chow, and 2% diet containing fat (DCF), respectively, for the remaining 10 weeks. Results revealed a significant effect of the low dose of Ca+2 supplement in form of ES than high dose and 2% DCF; on basis of anthropometric parameters, lipid, leptin, adiponectin, thyroid hormones, Ca+2 , 25-hydroxyl vitamin-D, and oxidative and inflammatory parameters were regulated. Results were confirmed with the histopathological study. Therefore, it was concluded that Ca+2 supplementation can be used as a beneficial source for obesity management with anticholesterol actions. PRACTICAL APPLICATIONS: Obesity represented public health hazards. The eggshell is one of the waste products that contain a high percentage of Ca+2 . The current data exposed using a low dose of ES as a new source of Ca+2 supplement for treatment of HFD rats leads to significant enhancement of lipid profiles, liver enzymes, kidney functions, leptin, adiponectin, Ca+2 , 25(OH)-D, TSH, fT4, and PTH levels. Also, there was a reduction in weight gain, Bwt, BMI, BG, insulin, and HOMA-IR. Moreover, the oxidant-pro-oxidant system was improved in both hepatic and adipose tissues where NO and TBARS concentrations were diminished, and SOD specific activity was elevated. Additionally, TNF-α and ADAM17 expression were downregulated. Hence, it was concluded that there was good evidence that diets supplemented with ES were associated with the reduction of obesity complications especially regulating fat processing and storage in the body.


Assuntos
Cálcio , Manejo da Obesidade , Animais , Suplementos Nutricionais , Casca de Ovo , Obesidade/tratamento farmacológico , Ratos
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 208: 150-156, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30312841

RESUMO

A flow injection based chemiluminescence process has been reported for vitamin D3 determination without using especial chemiluminescence reagent. Vitamin D3 shows enhancement on the CL intensity of diperiodatocuprate(III) with surfactant (Triton X-100) solution. The calibration curve was found to be linear over the concentration range 0.01-40 mg/L (R2 = 0.9997, n = 8) tested. A limit of detection (S/N = 3), limit of quantification (S/N = 10) and sample injection throughput of 2.5 × 10-3, 8.3 × 10-3 mg/L and 150 h-1 respectively were obtained. Various experimental variables were tested to get most suitable response, e.g., the concentrations of reagents, and their flow rates, sample injection volume and photomultiplier tube voltage. The effect of potential interferences was also examined. Vitamin D3 determination was successfully carried out in pharmaceutical formulations. The recoveries from the formulations were obtained in the range of 96 ±â€¯4-108 ±â€¯2%. The reaction mechanism discussion for diperiodatocuprate(III) complex-Triton X-100-vitamin D3 was also included.


Assuntos
Colecalciferol/análise , Composição de Medicamentos , Análise de Injeção de Fluxo/métodos , Medições Luminescentes/métodos , Tensoativos/química , Cobre/química , Etanol/química , Hidróxidos/química , Íons , Cinética , Compostos de Potássio/química , Soluções , Espectrofotometria Ultravioleta
11.
Int J Mol Sci ; 19(7)2018 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-29970863

RESUMO

It is suggested that several compounds, including G-quadruplex ligands, can target telomeres, inducing their uncapping and, ultimately, cell death. However, it has never been demonstrated whether such ligands can bind directly and quantitatively to telomeres. Here, we employed the property of platinum and platinum-G-quadruplex complexes to target G-rich sequences to investigate and quantify their covalent binding to telomeres. Using inductively coupled plasma mass spectrometry, surprisingly, we found that, in cellulo, in the presence of cisplatin, a di-functional platinum complex, telomeric DNA was platinated 13-times less than genomic DNA in cellulo, as compared to in vitro data. On the contrary, the amount of mono-functional platinum complexes (Pt-ttpy and Pt-tpy) bound either to telomeric or to genomic DNA was similar and occurred in a G-quadruplex independent-manner. Importantly, the quantification revealed that the low level of cisplatin bound to telomeric DNA could not be the direct physical cause of TRF2 displacement from telomeres. Altogether, our data suggest that platinum complexes can affect telomeres both directly and indirectly.


Assuntos
Cisplatino/química , Quadruplex G , Platina/química , Estrutura Molecular , Telômero/química
12.
Materials (Basel) ; 10(10)2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29036935

RESUMO

Laser cladding process was performed on a commercial Ti-6Al-4V (α + ß) titanium alloy by means of tungsten carbide-nickel based alloy powder blend. Nd:YAG laser with a 2.2-KW continuous wave was used with coaxial jet nozzle coupled with a standard powder feeding system. Four-track deposition of a blended powder consisting of 60 wt % tungsten carbide (WC) and 40 wt % NiCrBSi was successfully made on the alloy. The high content of the hard WC particles is intended to enhance the abrasion resistance of the titanium alloy. The goal was to create a uniform distribution of hard WC particles that is crack-free and nonporous to enhance the wear resistance of such alloy. This was achieved by changing the laser cladding parameters to reach the optimum conditions for favorable mechanical properties. The laser cladding samples were subjected to thorough microstructure examinations, microhardness and abrasion tests. Phase identification was obtained by X-ray diffraction (XRD). The obtained results revealed that the best clad layers were achieved at a specific heat input value of 59.5 J·mm-2. An increase by more than three folds in the microhardness values of the clad layers was achieved and the wear resistance was improved by values reaching 400 times.

13.
Bioconjug Chem ; 27(6): 1456-70, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27115175

RESUMO

G-quadruplex structures (G4) are promising anticancerous targets. A great number of small molecules targeting these structures have already been identified through biophysical methods. In cellulo, some of them are able to target either telomeric DNA and/or some sequences involved in oncogene promotors, both resulting in cancer cell death. However, only a few of them are able to bind to these structures G4 irreversibly. Here we combine within the same molecule the G4-binding agent PDC (pyridodicarboxamide) with a N-heterocyclic carbene-platinum complex NHC-Pt already identified for its antitumor properties. The resulting conjugate platinum complex NHC-Pt-PDC stabilizes strongly G-quadruplex structures in vitro, with affinity slightly affected as compared to PDC. In addition, we show that the new conjugate binds preferentially and irreversibly the quadruplex form of the human telomeric sequence with a profile in a way different from that of NHC-Pt thereby indicating that the platination reaction is oriented by stacking of the PDC moiety onto the G4-structure. In cellulo, NHC-Pt-PDC induces a significant loss of TRF2 from telomeres that is considerably more important than the effect of its two components alone, PDC and NHC-Pt, respectively.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , DNA/química , Quadruplex G/efeitos dos fármacos , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacologia , Telômero/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA/metabolismo , Humanos , Ligantes , Transporte Proteico/efeitos dos fármacos , Estereoisomerismo , Telômero/genética , Telômero/metabolismo , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo
14.
J Egypt Public Health Assoc ; 87(5-6): 90-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23196881

RESUMO

BACKGROUND: There is insufficient information on the usage of dietary supplements among Egyptians. The aim of this study was to identify the pattern of dietary supplement usage among employees of Alexandria University. PARTICIPANTS AND METHODS: A comparative cross-sectional study was carried out on 500 staff members, clerks, and workers of Alexandria University. The sample studied was equally allocated between seven institutions (three from medical sectors and four from nonmedical sectors), and was randomly selected from each institution after obtaining their verbal consent. Data on sociodemographic characteristics, medical history, lifestyle practices, dietary intake, and pattern of dietary supplement usage were collected from each participant. RESULTS: The use of dietary supplement was reported by 31.2% of the participants. These supplements were mainly multivitamins, iron, or calcium. Almost half of the users (52.6%) had used supplements regularly for years. The supplements were prescribed by doctors among 70.6% of the users for protection against diseases or to improve mental and physical well-being. The daily intake of the studied nutrients for both users and nonusers was found to be lesser than their requirements; also there was no statistically significant difference in the levels of nutrients studied, except in the adequacy of riboflavin, which was found to be higher among users than among nonusers (P=0.040). Female sex, higher educational and occupational levels, and the presence of chronic diseases were associated with the increased usage of dietary supplements. CONCLUSION AND RECOMMENDATION: Dietary intake of the studied nutrients for both users and nonusers of supplements was found to be less than their daily requirements. Nutritional education programs highlighting the importance of eating a balanced diet or the usage of dietary supplements are recommended for university employees.


Assuntos
Necessidades Nutricionais , Universidades , Estudos Transversais , Suplementos Nutricionais/estatística & dados numéricos , Egito , Humanos
15.
J Asian Nat Prod Res ; 11(5): 457-64, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19504389

RESUMO

Mutiniside (1), new phenolic glucoside, and the flavonoidal glucoside cephacoside (2) have been isolated from the n-BuOH soluble fraction, along with lupeol (3), beta-sitosterol (4), stigmasterol (5), methyl-4-hydroxybenzoate (6), taraxacin (7), ursolic acid (8), and beta-sitosterol-3-O-beta-D-glucopyranoside (9), have been isolated from the EtOAc soluble fraction of Abutilon muticum. Compounds 2-9 are reported for the first time from this species. Compound 1 showed significant antioxidant activity while moderate inhibitory activity was observed against the enzyme lipoxygenase.


Assuntos
Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Inibidores de Lipoxigenase/isolamento & purificação , Inibidores de Lipoxigenase/farmacologia , Malvaceae/química , Plantas Medicinais/química , Antioxidantes/química , Compostos de Bifenilo/farmacologia , Sequestradores de Radicais Livres/farmacologia , Glucosídeos/química , Inibidores de Lipoxigenase/química , Estrutura Molecular , Paquistão , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Picratos/farmacologia , Sitosteroides/química , Sitosteroides/isolamento & purificação
16.
J Enzyme Inhib Med Chem ; 23(1): 62-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18341255

RESUMO

A mild and efficient route to tetraketones (2-22) has been developed by way of tetraethyl ammonium bromide (Et(4)N(+)Br(- )) mediated condensation of dimedone (5,5-dimethylcyclohexane-1,3-dione, 1) with a variety of aldehydes. All these compounds showed significant lipoxygenase inhibitory activity and moderate to strong antioxidant potential. Compounds 19 (IC(50) = 7.8 microM), 22 (IC(50) = 12.5 microM), 3 (IC(50) = 16.3 microM), 11 (IC(50) = 17.5 microM) and 8 (IC(50) = 21.3 microM) showed significant inhibitory potential against lipoxygenase (baicalein, IC(50) = 22.4 microM). On the other hand compound 19 (IC(50) = 33.6 microM) also showed strong antioxidant activity compared to the standard (IC(50) = 44.7 microM). This study is likely to lead to the discovery of therapeutically efficient agents against very important disorders including inflammation, asthma, cancer and autoimmune diseases.


Assuntos
Antioxidantes/síntese química , Antioxidantes/farmacologia , Cetonas/síntese química , Cetonas/farmacologia , Inibidores de Lipoxigenase/síntese química , Inibidores de Lipoxigenase/farmacologia , Antioxidantes/química , Sequestradores de Radicais Livres/síntese química , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Cetonas/química , Inibidores de Lipoxigenase/química , Modelos Moleculares , Relação Estrutura-Atividade
17.
Chem Biodivers ; 4(1): 72-83, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17256736

RESUMO

Bractin A (=(2S,3S,4R,5E)-2-{[(2R)-2-hydroxydodecanoyl]amino}triacont-5-ene-1,3,4-triol; 1) and bractin B (=(2S,3S,4R,5E,8E)-2-{[(2R)-2-hydroxyhexacosanoyl]amino}pentadeca-5,8-diene-3,4,15-triol 1-O-beta-D-glucopyranoside; 2), new sphingolipids, and bractic acid (=(5Z,10Z,15Z)-2-decyl-4,7,8,12,13,17,18-heptahydroxy-20,23-dioxopentacosa-5,10,15-trienoic acid; 3), a long-chain polyhydroxy acid, were isolated from the whole plant Ajuga bracteosa along with four known diterpenoids 4-7. Their structures were deduced by spectral studies including 1D- and 2D-NMR spectroscopy. Compounds 1-3 displayed inhibitory potential against enzyme lipoxygenase, while compounds 4-7 inhibited cholinesterase enzymes in a concentration-dependent manner with IC(50) values in the range 10.0-33.0, 14.0-35.2, and 10.0-19.0 microM for lipoxygenase, acetylcholinesterase, and butyrylcholinesterase, respectively. Lineweaver-Burk, and Dixon plots, and their secondary replots indicated that all compounds exhibit non-competitive type of inhibition with K(i) values in the range of 9.5-35.2, 15.2-36.0, and 11.6-20.5 microM, for lipoxygenase, acetylcholinesterase, and butyrylcholinesterase, respectively.


Assuntos
Ajuga/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Ligação de Hidrogênio , Estrutura Molecular , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta
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