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1.
J Chem Ecol ; 47(12): 950-967, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34762210

RESUMO

Synthetic pheromones have been used for pest control over several decades. The conventional synthesis of di-unsaturated pheromone compounds is usually complex and costly. Camelina (Camelina sativa) has emerged as an ideal, non-food biotech oilseed platform for production of oils with modified fatty acid compositions. We used Camelina as a plant factory to produce mono- and di-unsaturated C12 chain length moth sex pheromone precursors, (E)-9-dodecenoic acid and (E,E)-8,10-dodecadienoic acid, by introducing a fatty acyl-ACP thioesterase FatB gene UcTE from California bay laurel (Umbellularia californica) and a bifunctional ∆9 desaturase gene Cpo_CPRQ from the codling moth, Cydia pomonella. Different transgene combinations were investigated for increasing pheromone precursor yield. The most productive Camelina line was engineered with a vector that contained one copy of UcTE and the viral suppressor protein encoding P19 transgenes and three copies of Cpo_CPRQ transgene. The T2 generation of this line produced 9.4% of (E)-9-dodecenoic acid and 5.5% of (E,E)-8,10-dodecadienoic acid of the total fatty acids, and seeds were selected to advance top-performing lines to homozygosity. In the T4 generation, production levels of (E)-9-dodecenoic acid and (E,E)-8,10-dodecadienoic acid remained stable. The diene acid together with other seed fatty acids were converted into corresponding alcohols, and the bioactivity of the plant-derived codlemone was confirmed by GC-EAD and a flight tunnel assay. Trapping in orchards and home gardens confirmed significant and specific attraction of C. pomonella males to the plant-derived codlemone.


Assuntos
Brassicaceae/química , Dodecanol/análogos & derivados , Engenharia Metabólica , Mariposas/efeitos dos fármacos , Atrativos Sexuais/farmacologia , Animais , Dodecanol/química , Dodecanol/metabolismo , Atrativos Sexuais/química
2.
FEMS Yeast Res ; 20(1)2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31942998

RESUMO

One strategy for overcoming infectious diseases caused by drug-resistant fungi involves combining drugs rendered inactive by resistance with agents targeting the drug resistance mechanism. The antifungal activity of n-dodecanol disappears as incubation time passes. In Saccharomyces cerevisiae, anethole, a principal component of anise oil, prolongs the transient antifungal effect of dodecanol by downregulating genes of multidrug efflux pumps, mainly PDR5. However, the detailed mechanisms of dodecanol's antifungal action and the anethole-induced prolonged antifungal action of dodecanol are unknown. Screening of S. cerevisiae strains lacking genes related to Ca2+ homeostasis and signaling identified a pmr1Δ strain lacking Golgi Ca2+-ATPase as more sensitive to dodecanol than the parental strain. Dodecanol and the dodecanol + anethole combination significantly increased intracellular Ca2+ levels in both strains, but the mutant failed to clear intracellular Ca2+ accumulation. Further, dodecanol and the drug combination reduced PMR1 expression and did not lead to specific localization of Pmr1p in the parental strain after 4-h treatment. By contrast with the parental strain, dodecanol did not stimulate PDR5 expression in pmr1Δ. Based on these observations, we propose that the antifungal activity of dodecanol is related to intracellular Ca2+ accumulation, possibly dependent on PMR1 function, with anethole enabling Ca2+ accumulation by restricting dodecanol efflux.


Assuntos
Anisóis/farmacologia , ATPases Transportadoras de Cálcio/genética , Cálcio/metabolismo , Dodecanol/farmacologia , Deleção de Genes , Chaperonas Moleculares/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Derivados de Alilbenzenos , Anisóis/química , Antifúngicos/química , Antifúngicos/farmacologia , ATPases Transportadoras de Cálcio/efeitos dos fármacos , ATPases Transportadoras de Cálcio/metabolismo , Dodecanol/química , Sinergismo Farmacológico , Citometria de Fluxo , Complexo de Golgi/enzimologia , Chaperonas Moleculares/efeitos dos fármacos , Chaperonas Moleculares/metabolismo , RNA Fúngico/química , RNA Fúngico/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/metabolismo , Transdução de Sinais/genética
3.
Colloids Surf B Biointerfaces ; 167: 385-391, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29702469

RESUMO

FAVs (fatty acid vesicles), originated from natural biomass and created available biointerface, have advantages of biocompatibility, low-cost, and easy self-assembly in aqueous solution due to their dynamic feature. However, there is no example of applying FAVs in contact with human body since they are inherently alkaline-adapted and pH windows for the FAV formation and application are very narrow and far away from the physiological pH range. In this work an attempt to turn the alkaline-adapted FAVs into neutral and acid-adapted ones was made by fabricating the amphiphile-hybrid vesicles of CLA (conjugated linoleic acid) with a typical cosmetic emulsifier SDS (sodium dodecylsulfate) and/or a co-emulsifier DA (dodecyl alcohol). pH windows for the SDS- and/or DA-hybrid FAV formation of CLA were judged by using dynamic light scattering criterion, and confirmed by small-angle X-ray scattering and room temperature transmission electron microscopy. The experimental results show that with the aid of H-bonding and ion-dipole forces among molecules of CLA, SDS and DA within the hybrid vesicle walls that were identified by Fourier transform infrared analysis, much wider pH windows of 2.5-11.7 for the hybrid FAVs were obtained by expansion from 8.0-9.0 for FAV of CLA alone, which was composition-dependent and made the hybrid FAVs become neutral and acid-adapted.


Assuntos
Ácidos/química , Ácidos Graxos/química , Ácidos Linoleicos Conjugados/química , Lipossomos/química , Dodecanol/química , Concentração de Íons de Hidrogênio , Luz , Lipossomos/ultraestrutura , Microscopia Eletrônica de Transmissão , Espalhamento de Radiação , Dodecilsulfato de Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
4.
Molecules ; 23(2)2018 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-29438284

RESUMO

Azelaic acid (AzA) and its derivatives have been known to be effective in the treatment of acne and various cutaneous hyperpigmentary disorders. The esterification of azelaic acid with lauryl alcohol (LA) to produce dilaurylazelate using immobilized lipase B from Candida antarctica (Novozym 435) is reported. Response surface methodology was selected to optimize the reaction conditions. A well-fitting quadratic polynomial regression model for the acid conversion was established with regards to several parameters, including reaction time and temperature, enzyme amount, and substrate molar ratios. The regression equation obtained by the central composite design of RSM predicted that the optimal reaction conditions included a reaction time of 360 min, 0.14 g of enzyme, a reaction temperature of 46 °C, and a molar ratio of substrates of 1:4.1. The results from the model were in good agreement with the experimental data and were within the experimental range (R² of 0.9732).The inhibition zone can be seen at dilaurylazelate ester with diameter 9.0±0.1 mm activities against Staphylococcus epidermidis S273. The normal fibroblasts cell line (3T3) was used to assess the cytotoxicity activity of AzA and AzA derivative, which is dilaurylazelate ester. The comparison of the IC50 (50% inhibition of cell viability) value for AzA and AzA derivative was demonstrated. The IC50 value for AzA was 85.28 µg/mL, whereas the IC50 value for AzA derivative was more than 100 µg/mL. The 3T3 cell was still able to survive without any sign of toxicity from the AzA derivative; thus, it was proven to be non-toxic in this MTT assay when compared with AzA.


Assuntos
Ácidos Dicarboxílicos/química , Dodecanol/química , Enzimas Imobilizadas/química , Ésteres/química , Proteínas Fúngicas/química , Lipase/química , Animais , Biocatálise , Sobrevivência Celular/efeitos dos fármacos , Ácidos Dicarboxílicos/farmacologia , Ésteres/farmacologia , Análise Fatorial , Cinética , Camundongos , Testes de Sensibilidade Microbiana , Modelos Estatísticos , Células NIH 3T3 , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/crescimento & desenvolvimento
5.
Artigo em Inglês | MEDLINE | ID: mdl-29132021

RESUMO

A new fibroin/dodecanol floating solidification microextraction, coupled with high performance liquid chromatography, was developed and applied for enrichment and quantification of the trace flavonoids in traditional Chinese medicine and biological samples. Also, fibroin sensibilization mechanism was described, and influence of sample matrix to enrichment factor was investigated. In this method, a homogeneous fibroin/dodecanol of dispersed solution was employed as microextraction phase to flavonoids (myricetin, quercetin, isorhamnetin, chrysin, kaempferide), the several critical parameters affecting the performance, such as organic extractant, amount of fibroin in organic extractant, volume of extraction phase, dispersant, salt concentration, pH of sample phase, stirring rate, extraction time, and volume of sample phase were tested and optimized. Under the optimized conditions, enrichment factor of flavonoids ranged from 42.4 to 238.1 in different samples, excellent linearities with r2≥ 0.9968 for all analytes were achieved, limits of detection were less than or equal to 5.0ng/mL, average recoveries were 92.5% to 115.0% in different samples. The new procedure is simple, fast, low cost, environmentally friendly and high EF, it can also be applied to the concentration and enrichment of the trace flavonoids in other complex matrixes.


Assuntos
Dodecanol/química , Fibroínas/química , Flavonoides/análise , Flavonoides/isolamento & purificação , Microextração em Fase Sólida/métodos , Flavonoides/sangue , Flavonoides/urina , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
6.
Nat Prod Res ; 31(22): 2604-2611, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28278665

RESUMO

Phytochemical analyses of the chloroform extract of Piper betle L. var. birkoli, Piperaceae, leaves led to the isolation of two new phenylpropanoid analogues: bis-chavicol dodecanoyl ester (2) and bis-hydroxychavicol dodecanoyl ester (3), along with one known compound: allyl-3-methoxy-4-hydroxybenzene (1) on the basis of spectroscopic data 1D (1H and 13C) and 2D (1H-1H COSY and HMBC) NMR, as well as ESI-MS, FT-IR, HR-ESI-MS and LC-ESI-MS. Compound 2 and 3 exhibited excellent antioxidant DPPH radical scavenging activity with IC50 values of 12.67 µg/mL and 1.08 µg/mL compared to ascorbic acid as a standard antioxidant drug with IC50 value of 6.60 µg/mL. Evaluation of cytotoxic activity against two human oral cancer cell lines (AW13516 and AW8507) showed significant effect with GI50 values of 19.61 and 23.01 µg/mL for compound 2 and 10.25 and 13.12 µg/mL for compound 3, compared to Doxorubicin® as a standard cytotoxic drug with GI50 value of < 10 µg/mL.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Piper betle/química , Compostos Alílicos/química , Compostos Alílicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Cromatografia Líquida , Dodecanol/química , Dodecanol/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Neoplasias Bucais/tratamento farmacológico , Fenóis/química , Fenóis/farmacologia , Folhas de Planta/química , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier
7.
ChemSusChem ; 10(5): 825-829, 2017 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-28032695

RESUMO

For the first time, we demonstrated two integrated processes for the direct synthesis of dodecanol or 2,4,8-trimethylnonane (a jet fuel range C12 -branched alkane) using methyl isobutyl ketone (MIBK) that can be derived from lignocellulose. The reactions were carried out in dual-bed continuous flow reactors. In the first bed, MIBK was selectively converted to a mixture of C12 alcohol and ketone. Over the Pd-modified magnesium- aluminium hydrotalcite (Pd-MgAl-HT) catalyst, a high total carbon yield (73.0 %) of C12 oxygenates can be achieved under mild conditions. In the second bed, the C12 oxygenates generated in the first bed were hydrogenated to dodecanol over a Ru/C catalyst or hydrodeoxygenated to 2,4,8-trimethylnonane over a Cu/SiO2 catalyst. The as-obtained dodecanol can be used as feedstock in the production of sodium dodecylsulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS), which are widely used as surfactants or detergents. The asobtained 2,4,8-trimethylnonane can be blended into conventional jet fuel without hydroisomerization.


Assuntos
Alcanos/síntese química , Dodecanol/síntese química , Metil n-Butil Cetona/química , Alcanos/química , Catálise , Técnicas de Química Sintética , Dimerização , Dodecanol/química
8.
Food Chem ; 220: 249-256, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27855896

RESUMO

Lauryl ferulate (LF) was synthesized through lipase-catalyzed esterification of ferulic acid (FA) with lauryl alcohol in a novel ionic liquid ([(EO)-3C-im][NTf2]), and its antibacterial activities was evaluated in vitro against three food-related bacteria. [(EO)-3C-im][NTf2] was first synthesized through incorporating alkyl ether moiety into the double imidazolium ring. [(EO)-3C-im][NTf2] containing hexane was found to be the most suitable for this reaction. The effects of various parameters were studied, and the maximum yield of LF (90.1%) was obtained in the optimum reaction conditions, in [(EO)-3C-im][NTf2]/hexane (VILs:Vhexane=1:1) system, 0.08mmol/mL of FA concentration, 50mg/mL Novozym 435, 60°C. LF exhibited a stronger antibacterial activity against Gram-negative (25 mm) than Gram-positive (21.5-23.2 mm) bacteria. The lowest MIC value was seen for E. coli (1.25mM), followed by L. Monocytogenes (2.5mM) and S.aureus (5mM). The MBCs for L. Monocytogenes, S.aureus and E. coli were 10, 20 and 5mM.


Assuntos
Antibacterianos/farmacologia , Ácidos Cumáricos/química , Dodecanol/química , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Lipase/química , Antibacterianos/química , Catálise , Enzimas Imobilizadas , Escherichia coli/efeitos dos fármacos , Esterificação , Proteínas Fúngicas , Líquidos Iônicos/química , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
9.
Artigo em Inglês | MEDLINE | ID: mdl-27262083

RESUMO

A new method for the simultaneous determination of the three antifungal drugs using ultrasonic-assisted supramolecular dispersive liquid-liquid microextraction based on solidification of a floating organic droplet (UASMDLLME-SFO) was proposed. The supramolecular solvents produced from reversed micelles of 1-dodecanol (extraction solvent) in tetrahydrofuran (THF) were injected into the aqueous sample solution. Reverse micelle coacervates were produced in situ through self-assembly processes. The antifungal drugs were extracted from the aqueous sample into a supramolecular solvent. Sonication accelerated the mass transfer of the target analytes into the supramolecular solvent phase and enhanced the dispersion process. Some parameters affecting the extraction efficiency such as type and volume of the extraction solvent, pH, volume of the disperser solvent and ultrasound extraction time were investigated. Under optimum conditions, the limits of detections for ketoconazole, clotrimazole and miconazole ranged from 0.08 to 1.3µgL(-1) and the relative standard deviations (RSDs, n=5)<6% were obtained. The method was successfully applied for preconcentration of the three drugs in biological and water samples.


Assuntos
Antifúngicos/análise , Antifúngicos/sangue , Cromatografia Líquida de Alta Pressão/métodos , Água Potável/análise , Microextração em Fase Líquida/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/sangue , Antifúngicos/urina , Dodecanol/química , Furanos/química , Humanos , Limite de Detecção , Micelas , Solventes/química , Sonicação/métodos , Poluentes Químicos da Água/urina
10.
Mol Pharm ; 13(6): 1822-32, 2016 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-26981724

RESUMO

Hedgehog (Hh) signaling plays an important role in the development and metastasis of pancreatic ductal adenocarcinoma (PDAC). Although gemcitabine (GEM) has been used as a first-line therapy for PDAC, its rapid metabolism and short plasma half-life restrict its use as a single chemotherapy. Combination therapy with more than one drug is a promising approach for treating cancer. Herein, we report the use of methoxy poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate)-graft-dodecanol (mPEG-b-PCC-g-DC) copolymer for conjugating GEM and encapsulating a Hh inhibitor, vismodegib (GDC-0449), into its hydrophobic core for treating PDAC. Our objective was to determine whether the micelle mixtures of these two drugs could show better response in inhibiting Hh signaling pathway and restraining the proliferation and metastasis of pancreatic cancer. The in vivo stability of GEM significantly increased after conjugation, which resulted in its increased antitumor efficacy. Almost 80% of encapsulated GDC-0449 and 19% conjugated GEM were released in vitro at pH 5.5 in 48 h in a sustained manner. The invasion, migration, and colony forming features of MIA PaCa-2 cells were significantly inhibited by micelle mixture carrying GEM and GDC-0449. Remarkable increase in PARP cleavage and Bax proved increased apoptosis by this combination formulation compared to individual micelles. This combination therapy efficiently inhibited tumor growth, increased apoptosis, reduced Hh ligands PTCH-1 and Gli-1, and lowered EMT-activator ZEB-1 when injected to athymic nude mice bearing subcutaneous tumor generated using MIA PaCa-2 cells compared to monotherapy as observed from immunohistochemical analysis. In conclusion, micelle mixtures carrying GEM and GDC-0449 have the potential to treat pancreatic cancer.


Assuntos
Anilidas/administração & dosagem , Anilidas/química , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/tratamento farmacológico , Piridinas/administração & dosagem , Piridinas/química , Adenocarcinoma/tratamento farmacológico , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/química , Apoptose/efeitos dos fármacos , Carcinoma Ductal Pancreático/tratamento farmacológico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Desoxicitidina/química , Dodecanol/química , Humanos , Masculino , Camundongos , Camundongos Nus , Micelas , Polietilenoglicóis/química , Polímeros/química , Propano/análogos & derivados , Propano/química , Transdução de Sinais/efeitos dos fármacos , Gencitabina
11.
Mol Pharm ; 12(4): 1289-98, 2015 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-25679326

RESUMO

Successful treatment of pancreatic ductal adenocarcinoma (PDAC) remains a challenge due to the desmoplastic microenvironment that promotes both tumor growth and metastasis and forms a barrier to chemotherapy. Hedgehog (Hh) signaling is implicated in initiation and progression of PDAC and also contributes to desmoplasia. While Hh levels are increased in pancreatic cancer cells, levels of tumor suppressor miR-let7b, which targets several genes involved in PDAC pathogenesis, is downregulated. Therefore, our overall objective was to inhibit Hh pathway and restore miR-let7b simultaneously for synergistically treating PDAC. miR-let7b and Hh inhibitor GDC-0449 could inhibit the proliferation of human pancreatic cancer cells (Capan-1, HPAF-II, T3M4, and MIA PaCa-2), and there was synergistic effect when miR-let7b and GDC-0449 were coformulated into micelles using methoxy poly(ethylene glycol)-block-poly(2-methyl- 2-carboxyl-propylenecarbonate-graft-dodecanol-graft-tetraethylene-pentamine) (mPEG-b-PCC-g-DC-g-TEPA). This copolymer self-assembled into micelles of <100 nm and encapsulated hydrophobic GDC-0449 into its core with 5% w/w drug loading and allowed complex formation between miR-let7b and its cationic pendant chains. Complete polyplex formation with miRNA was observed at the N/P ratio of 16/1. Almost 80% of GDC-0449 was released from the polyplex in a sustained manner in 2 days. miRNA in the micelle formulation was stable for up to 24 h in the presence of serum and high uptake efficiency was achieved with low cytotoxicity. This combination therapy effectively inhibited tumor growth when injected to athymic nude mice bearing ectopic tumor generated using MIA PaCa-2 cells compared to micelles carrying GDC-0449 or miR-let7b alone. Immunohistochemical analysis revealed decreased tumor cell proliferation with increased apoptosis in the animals treated with miR-let7b and GDC-0449 combination.


Assuntos
Adenocarcinoma/tratamento farmacológico , Proteínas Hedgehog/química , MicroRNAs/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Adenocarcinoma/metabolismo , Alcenos/química , Anilidas/química , Animais , Carbonatos/química , Cátions , Linhagem Celular Tumoral , Sobrevivência Celular , Progressão da Doença , Dodecanol/química , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Endossomos/metabolismo , Etilenodiaminas/química , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Nus , Micelas , Transplante de Neoplasias , Neoplasias Pancreáticas/metabolismo , Polietilenoglicóis/química , Polímeros/química , Piridinas/química , Transdução de Sinais
12.
J Biomol Screen ; 19(10): 1409-14, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25296658

RESUMO

Plastic labware is used in all processes of modern pharmaceutical research, including compound storage and biological assays. The use of these plastics has created vast increases in productivity and cost savings as experiments moved from glass test tubes and capillary pipettes to plastic microplates and multichannel liquid handlers. One consequence of the use of plastic labware, however, is the potential release of contaminants and their resultant effects on biological assays. We report herein the identification of biologically active substances released from a commonly used plastic microplate. The active contaminants were identified by gas chromatography-mass spectroscopy as dodecan-1-ol, dodecyl 3-(3-dodecoxy-3-oxopropyl)sulfanylpropanoate, and dodecanoic acid, and they were found to be selective monoamine oxidase-B inhibitors.


Assuntos
Avaliação Pré-Clínica de Medicamentos/instrumentação , Inibidores da Monoaminoxidase/farmacologia , Plásticos/química , Ácido 3-Mercaptopropiônico/análogos & derivados , Ácido 3-Mercaptopropiônico/farmacologia , Dodecanol/química , Dodecanol/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Cromatografia Gasosa-Espectrometria de Massas , Ácidos Láuricos/farmacologia , Monoaminoxidase/metabolismo , Plásticos/farmacologia , Razão Sinal-Ruído , Sulfetos/farmacologia
13.
Talanta ; 123: 25-31, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24725860

RESUMO

Dispersive-solidification liquid-liquid microextraction (DSLLME) coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of inorganic arsenic (III, V) in water samples. At pH=1, As(III) formed complex with ammonium pyrrolidine dithiocarbamate (APDC) and extracted into the fine droplets of 1-dodecanol (extraction solvent) which were dispersed with ethanol (disperser solvent) into the water sample solution. After extraction, the organic phase was separated by centrifugation, and was solidified by transferring into an ice bath. The solidified solvent was transferred to a conical vial and melted quickly at room temperature. As(III) was determined in the melted organic phase while As(V) remained in the aqueous layer. Total inorganic As was determined after the reduction of the pentavalent forms of arsenic with sodium thiosulphate and potassium iodide. As(V) was calculated by difference between the concentration of total inorganic As and As(III). The variable of interest in the DSLLME method, such as the volume of extraction solvent and disperser solvent, pH, concentration of APDC (chelating agent), extraction time and salt effect, was optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). In the optimum conditions, the proposed method has been successfully applied to the determination of inorganic arsenic in different environmental water samples and certified reference material (NIST RSM 1643e).


Assuntos
Arsênio/análise , Microextração em Fase Líquida/métodos , Espectrofotometria Atômica/métodos , Poluentes Químicos da Água/análise , Algoritmos , Arsênio/isolamento & purificação , Dodecanol/química , Água Potável/química , Monitoramento Ambiental/métodos , Concentração de Íons de Hidrogênio , Iodeto de Potássio/química , Pirrolidinas/química , Reprodutibilidade dos Testes , Rios/química , Água do Mar/química , Solventes/química , Tiocarbamatos/química , Tiossulfatos/química , Poluentes Químicos da Água/isolamento & purificação , Abastecimento de Água/análise
14.
Environ Entomol ; 43(2): 291-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24534117

RESUMO

Research to discover and develop attractants for the codling moth, Cydia pomonella L., has involved identification of the chemicals eliciting moth orientation to conspecific female moths, host fruits, fermented baits, and species of microbes. Pear ester, acetic acid, and N-butyl sulfide are among those chemicals reported to attract or enhance attractiveness to codling moth. We evaluated the trapping of codling moth with N-butyl sulfide alone and in combination with acetic acid and pear ester in apple orchards. Acetic acid was attractive in two tests and N-butyl sulfide was attractive in one of two tests. N-Butyl sulfide increased catches of codling moth when used with acetic acid to bait traps. N-Butyl sulfide also increased catches of codling moth when added to traps baited with the combination of acetic acid and pear ester. Male and female codling moth both responded to these chemicals and chemical combinations. These results provide a new three-component lure comprising N-butyl sulfide, acetic acid, and pear ester that is stronger for luring codling moth females than other attractants tested.


Assuntos
Controle de Insetos/métodos , Mariposas/fisiologia , Atrativos Sexuais/química , Sulfetos/química , Ácido Acético/química , Ácido Acético/farmacologia , Análise de Variância , Animais , Dodecanol/análogos & derivados , Dodecanol/química , Feminino , Masculino , Atrativos Sexuais/farmacologia , Sulfetos/farmacologia
15.
Chemosphere ; 103: 51-8, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24332733

RESUMO

A simple, rapid, effective and eco-friendly preconcentration method, vortex-assisted low density solvent based solvent demulsified dispersive liquid-liquid microextraction (VLDS-SD-DLLME), followed by high performance liquid chromatography-diode array detector (HPLC-DAD) analysis, has been developed for the first time for the determination of four organophosphorus pesticides (OPPs) (e.g., azinphos-methyl, parathion-methyl, fenitrothion and diazinon) in environmental water samples. In this preconcentration procedure, an emulsion was obtained after the mixture of extraction solvent (1-dodecanol) and dispersive solvent (acetonitrile, ACN) was injected rapidly into 10 mL of the sample solution. The vortex agitator aided the dispersion of the extraction solvent into the sample solution. After the formation of an emulsion, the demulsifier (ACN) was added, resulting in the rapid separation of the mixture into two phases without centrifugation. Under optimal conditions, the proposed method provided high extraction efficiency (90-99%), good linearity range (0.5-500 ng mL(-1)), low limits of detection (0.25-1 ng mL(-1)) and good repeatability and recoveries were obtained.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Microextração em Fase Líquida , Compostos Organofosforados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Dodecanol/química , Emulsões , Limite de Detecção , Solventes/química
16.
J Colloid Interface Sci ; 427: 80-90, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24360842

RESUMO

A key challenge in biomass conversion is how to achieve valuable molecules with optimal reactivity in the presence of immiscible reactants. This issue is usually tackled using either organic solvents or surfactants to promote emulsification, making industrial processes expensive and not environmentally friendly. As an alternative, Pickering emulsions using solid particles with tailored designed surface properties can promote phase contact within intrinsically biphasic systems. Here we show that amphiphilic silica nanoparticles bearing a proper combination of alkyl and strong acidic surface groups can generate stable Pickering emulsions of the glycerol/dodecanol system in the temperature range of 35-130°C. We also show that such particles can perform as Pickering Interfacial Catalysts for the acid-catalyzed etherification of glycerol with dodecanol at 150°C. Our findings shed light on some key parameters governing emulsion stability and catalytic activity of Pickering interfacial catalytic systems. This understanding is critical to pave the way toward technological solutions for biomass upgrading able to promote eco-efficient reactions between immiscible organic reagents with neither use of solvents nor surfactants.


Assuntos
Dodecanol/química , Emulsões/química , Glicerol/química , Nanopartículas/química , Dióxido de Silício/química , Tensoativos/química , Biomassa , Catálise , Temperatura Alta , Nanopartículas/ultraestrutura
17.
Mater Sci Eng C Mater Biol Appl ; 33(8): 4512-9, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24094153

RESUMO

Composite scaffolds consisting of polymers reinforced with ceramic nanoparticles are widely applied for hard tissue engineering. However, due to the incompatible polarity of ceramic nanoparticles with polymers, they tend to agglomerate in the polymer matrix which results in undesirable effects on the integral properties of composites. In this research, forsterite (Mg2SiO4) nanoparticles was surface esterified by dodecyl alcohol and nanofibrous poly(ε-caprolactone)(PCL)/modified forsterite scaffolds were developed through electrospinning technique. The aim of this research was to investigate the properties of surface modified forsterite nanopowder and PCL/modified forsterite scaffolds, before and after hydrolytic treatment, as well as the cellular attachment and proliferation. Results demonstrated that surface modification of nanoparticles significantly enhanced the tensile strength and toughness of scaffolds upon 1.5- and 4-folds compared to unmodified samples, respectively, due to improved compatibility between matrix and filler. Hydrolytic treatment of scaffolds also modified the bioactivity and cellular attachment and proliferation due to greatly enhanced hydrophilicity of the forsterite nanoparticles after this process compared to surface modified samples. Results suggested that surface modification of forsterite nanopowder and hydrolytic treatment of the developed scaffolds were effective approaches to address the issues in the formation of composite fibers and resulted in development of bioactive composite scaffolds with ideal mechanical and structural properties for bone tissue engineering applications.


Assuntos
Nanofibras/química , Poliésteres/química , Compostos de Silício/química , Engenharia Tecidual , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dodecanol/química , Esterificação , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Camundongos , Nanofibras/toxicidade , Propriedades de Superfície , Resistência à Tração , Alicerces Teciduais
18.
J Phys Chem B ; 117(32): 9400-11, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23906181

RESUMO

Synthetic amino acid-based surfactants possess versatile aggregation properties and are typically more biocompatible and biodegradable than surfactants with conventional headgroups. This opens the possibility of a myriad of specialty applications, namely in pharmaceutics, cosmetics, biomedicine, and nanotemplating chemistry. In this work, we have investigated the interfacial and self-assembling properties in aqueous medium of novel double-chained lysine-based surfactants, with particular focus on the behavior of the dodecyl derivative, 12Lys12. Upon cooling from dilute isotropic micellar solutions, this surfactant crystallizes into micrometer-sized tubular structures that induce gelation of the system. The tubules have been characterized in terms of morphology, assembly process, thermal behavior, and stability, by using differential scanning calorimetry, light and scanning electron microscopy, and deuterium NMR. Possible mechanisms for tubule assembly are discussed, on the basis of surfactant molecular shape, H-bonding and electrostatic interactions, and chirality effects.


Assuntos
Dodecanol/química , Lisina/química , Tensoativos/química , Ânions , Concentração de Íons de Hidrogênio , Micelas , Microscopia Eletrônica de Varredura , Estrutura Molecular , Tensão Superficial , Termodinâmica
19.
J Control Release ; 172(2): 436-43, 2013 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-23751568

RESUMO

The aim of this study was to investigate the effect of a specific and frequently used end group (lauryl alcohol) on the protein release and degradation kinetics of poly(DL-lactic-co-glycolic acid) particles of different sizes. Lauryl-capped PLGA and uncapped PLGA (referred to as PLGA-capped and PLGA-COOH, respectively) particles (0.3, 1 and 20 µm) were prepared by a double emulsion solvent evaporation technique. Bovine serum albumin (BSA) was used as a model protein for release studies. During degradation (PBS buffer, pH7.4 at 37°C), a slower dry mass loss was observed for 0.3 µm particles than for particles of 1 and 20 µm. It was further shown that PLGA-capped particles showed slower mass loss likely due to its more hydrophobic nature. It was found that the ester bond hydrolysis rate was substantially slower for PLGA-capped particles and that the rate increased with particle size. Particles showed enrichment in lactic acid content (and thus a decrease in glycolic acid content) in time, and interestingly PLGA-capped particles showed also an enrichment of the lauryl alcohol content. No difference was observed in degradation kinetics between BSA loaded and blank particles. Independent of size, PLGA-COOH based particles showed, after a small burst, a sustained and nearly complete release of BSA during 60-80 days. On the other hand, particles based on PLGA-capped showed a much slower release and exhibited incomplete release, accompanied by the presence of an insoluble residue remaining even after 180 days. FTIR analysis of this residue showed that it contained both polymer and protein. Considering the polymer enrichment in lauryl alcohol, the incomplete release observed for PLGA-capped is likely attributed to interactions between the protein and the lauryl end group. In conclusion, since PLGA-COOH, in contrast to the capped derivative, shows complete degradation as well as quantitative release of an entrapped protein, this polymer is preferred for the design of protein formulations.


Assuntos
Dodecanol/química , Portadores de Fármacos/química , Ácido Láctico/química , Ácido Poliglicólico/química , Soroalbumina Bovina/administração & dosagem , Animais , Bovinos , Dodecanol/metabolismo , Portadores de Fármacos/metabolismo , Hidrólise , Ácido Láctico/metabolismo , Tamanho da Partícula , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
20.
Pest Manag Sci ; 69(11): 1280-90, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23554261

RESUMO

BACKGROUND: Pheromone antagonists are good disruptants of the pheromone communication in insects and, as such, have been used in mating disruption experiments. In this study, new non-fluorinated electrophilic keto derivatives structurally related to the pheromone of Cydia pomonella (codlemone) have been synthesised and tested as putative pheromone antagonists. RESULTS: Codlemone (1) was prepared in excellent stereoselectivity in a new, iterative approach involving two Horner-Wadsworth-Emmons reactions. Methyl ketone (2), keto ester (3) and diketone (4) were obtained from codlemone in straightforward approaches in good overall yields and excellent stereochemical purity (≥98% E,E). In electrophysiology, only compound 2 displayed inhibition of the antennal response to the pheromone after presaturation of the antennal receptors. Compounds 2 to 4 did not inhibit the pheromone-degrading enzyme responsible for codlemone metabolism, but mixtures of ketone 2 and diketone 4 with codlemone elicited erratic flights on males in a wind tunnel. In the field, blends of either compound (2 or 4) with the pheromone caught significantly fewer males than codlemone alone. CONCLUSION: Codlemone and the potential antagonists 2 to 4 have been synthesised in good yields and excellent stereoselectivity. These chemicals behave as pheromone antagonists of the codling moth both in the laboratory and in the field.


Assuntos
Dodecanol/análogos & derivados , Mariposas/efeitos dos fármacos , Mariposas/fisiologia , Atrativos Sexuais/farmacologia , Animais , Dodecanol/antagonistas & inibidores , Dodecanol/síntese química , Dodecanol/química , Dodecanol/farmacologia , Feminino , Masculino , Atrativos Sexuais/antagonistas & inibidores , Atrativos Sexuais/síntese química , Atrativos Sexuais/química
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