RESUMO
In the present study, we assess tyrosol derivatives bearing 3,5-disubstituted isoxazoles and 1,4-disubstituted triazoles for their ability to inhibit the proliferation of K562 cells derived from leukemia as well as primary chronic myeloid leukemia (CML) cells obtained from the peripheral blood of 15 CML patients including 10 patients with untreated chronic phase and 5 patients with resistance against imatinib or multiple TKI. Our results showed that most derivatives displayed significant anti-proliferative activity against K562 cells in a dose-dependent manner. Among them, compounds 3d and 4a exhibited greater potent anticancer activity with respective IC50 values of 16 and 18 µg/mL (45 µM and 61 µM). Interestingly, compound 3d inhibited CML cell proliferation not only in newly diagnosed but also in imatinib-resistant patients. We demonstrated that the anti-proliferative effect of this compound is mediated by a pro-apoptotic activity by promoting oxidative stress and modulating the activity of the Akt, p38 MAPK and Erk 1/2 pathways. In conclusion, our data highlight the potential of this class of derivative as a novel promising therapeutic agent for CML therapy.
Assuntos
Antineoplásicos , Leucemia Mielogênica Crônica BCR-ABL Positiva , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Humanos , Mesilato de Imatinib/farmacologia , Isoxazóis/farmacologia , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Álcool Feniletílico/análogos & derivados , Triazóis/farmacologia , Triazóis/uso terapêuticoRESUMO
Two series of 3,5-disubstituted isoxazoles (6a-e) and 1,4-disubstituted triazoles (8a-e) derivatives have been synthesized from tyrosol (1), a natural phenolic compound, detected in several natural sources such as olive oil, and well-known by its wide spectrum of biological activities. Copper-catalyzed microwave-assisted 1,3-dipolar cycloaddition reactions between tyrosol-alkyne derivative 2 and two series of aryl nitrile oxides (5a-e) and azides (7a-e) regiospecifically afforded 3,5-disubstituted isoxazoles (6a-e) and 1,4-triazole derivatives (8a-e), respectively in quantitative yields. Synthesized compounds were purified and characterized by spectroscopic means including 1D and 2D NMR techniques and HRMS analysis. The newly prepared hybrid molecules have been evaluated for their anticancer and hemolytic activities. Results showed that most derivatives displayed significant antiproliferative activity against human glioblastoma cancer cells (U87) in a dose-dependent manner. Compounds 6d (IC50 = 15.2 ± 1.0 µg/mL) and 8e (IC50 = 21.0 ± 0.9 µg/mL) exhibited more potent anticancer activity. Moreover, most derivatives displayed low hemolytic activity, even at higher concentrations which suggested that these classes of compounds are suitable candidates for further in vivo investigations. The obtained results allow us to consider the newly synthesized isoxazole- and triazole-linked tyrosol derivatives as promising scaffolds for the development of effective anticancer agents.
Assuntos
Antineoplásicos/farmacologia , Glioblastoma/tratamento farmacológico , Isoxazóis/farmacologia , Álcool Feniletílico/análogos & derivados , Triazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma/patologia , Humanos , Isoxazóis/química , Estrutura Molecular , Álcool Feniletílico/química , Álcool Feniletílico/farmacologia , Relação Estrutura-Atividade , Triazóis/química , Células Tumorais CultivadasRESUMO
AIMS: This study aimed to evaluate the effect of oleuropein (OLE), the main phenolic compound present in olive leaves, on kidney ischemia-reperfusion injury (IRI) and to explore the underlying protective mechanism. MAIN METHODS: Rat kidneys were subjected to 60 min of bilateral warm ischemia followed by 120 min of reperfusion. OLE was administered orally 48 h, 24 h and 30 min prior to ischemia at doses of 10, 50 and 100 mg/kg body weight. The creatinine, urea, uric acid concentrations and lactate dehydrogenase (LDH) activity in plasma were evaluated. Oxidative stress and inflammation parameters were also assessed. Renal expression of AMP-activated protein kinase (p-AMPK), endothelial nitric oxide synthase (eNOS), mitogen-activated protein kinases (MAPK), inflammatory proteins and apoptotic proteins were evaluated using Western blot. KEY FINDINGS: Our results showed that OLE at 50 mg/kg reduced kidney IRI as revealed by a significant decrease of plasmatic creatinine, urea, uric acid concentrations and LDH activity. In parallel, OLE up-regulated antioxidant capacities. Moreover, OLE diminished the level of CRP and the expression of cyclooxygenase 2 (COX-2). Finally, OLE enhanced AMPK phosphorylation as well as eNOS expression whereas MAPK, and cleaved caspase-3 implicated in cellular apoptosis were attenuated in the ischemic kidneys. SIGNIFICANCE: In conclusion, this study shows that OLE could be used as therapeutic agent to reduce IRI through its anti-oxidative, anti-inflammatory and anti-apoptotic properties.
Assuntos
Inflamação/prevenção & controle , Iridoides/farmacologia , Rim/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/farmacologia , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glucosídeos Iridoides , Iridoides/administração & dosagem , Rim/patologia , Masculino , Ratos , Ratos Wistar , Traumatismo por Reperfusão/fisiopatologia , Fatores de TempoRESUMO
In this study, the enzymatic synthesis of phenylacetoyl glycerol ester was carried out as a response to the increasing consumer demand for natural compounds. 1,3-dihydroxyphenylacetoyl-sn-Glycerol (1,3-di-HPA-Gly), labeled as "natural" compound with interesting biological properties, has been successfully synthesized for the first time in good yield by a direct esterification of glycerol (Gly) with p-hydroxyphenylacetic acid (p-HPA) using immobilized Candida antarctica lipase as a biocatalyst. Spectroscopic analyses of purified esters showed that the glycerol was mono- or di-esterified on the primary hydroxyl group. These compounds were evaluated for their antioxidant activity using two different tests. The glycerol di-esters (1,3-di-HPA-Gly) showed a higher antiradical capacity than that of the butyl hydroxytoluene. Furthermore, compared to the p-HPA, synthesized ester (1,3-di-HPA-Gly) exhibited the most antibacterial effect mainly against Gramâ¯+â¯bacteria. Among synthesized esters the 1,3-di-HPA-Gly was most effective as antioxidant and antibacterial compound. These findings could be the basis for a further exploitation of the new compound, 1,3-di-HPA-Gly, as antioxidant and antibacterial active ingredient in the cosmetic and pharmaceutical fields.
Assuntos
Antibacterianos/síntese química , Antioxidantes/síntese química , Candida/enzimologia , Proteínas Fúngicas/química , Glicerol/síntese química , Lipase/química , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Proteínas Fúngicas/metabolismo , Glicerol/análogos & derivados , Glicerol/química , Glicerol/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Lipase/metabolismo , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Espectroscopia de Infravermelho com Transformada de Fourier , Espectrometria de Massas em TandemRESUMO
Antioxidants are highly important gradients used to preserve cosmetic products and reduce the effect of oxidative stress on the skin. The present work explores the possibility of using phenolic compounds of olive mill wastewater (OMW) as effective alternatives to the commercial antioxidants used in cosmetic formulations deemed by their allergic and carcinogenic effects. Esterification of tyrosol and hydroxytyrosol extracted from OMW with various fatty acids was conducted using Novozyme 435 lipase as a biocatalyst. Upon synthesis, butyrate, caprate, laurate, and palmitate tyrosyl and hydroxytyrosyl esters were isolated and evaluated for their antioxidant and antibacterial activities. Results showed that laurate derivatives are the most efficient in preventing lipid oxidation and inhibiting growth of pathogenic strains. In the prospective of industrial use, laurate tyrosyl and hydroxytyrosyl derivatives were incorporated in a formulation of moisturizer to substitute the commercial antioxidant butylated hydroxyltoluene. Oleuropein, extracted from olive leaves powder, was also tested as an antiaging ingredient in cosmetic formulations. The evaluation of physicochemical, microbiological, and sensorial properties of the new cosmetic products indicated that oleuropein and lipophilic derivatives do not affect the properties of the standard formulation. Oleuropein and lipophilic derivatives can be added as active ingredients to stabilize cosmetic preparations.
Assuntos
Antibacterianos/isolamento & purificação , Antioxidantes/isolamento & purificação , Azeite de Oliva/química , Fenóis/isolamento & purificação , Águas Residuárias/química , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Relação Dose-Resposta a Droga , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Fenóis/química , Fenóis/farmacologia , Relação Estrutura-AtividadeRESUMO
Synthesized lipophilic tyrosyl ester derivatives with increasing lipophilicity were effective against Leishmania (L.) major and Leishmania infantum species in vitro. These findings prompted us to test in vivo leishmanicidal properties of these molecules and their potential effect on the modulation of immune responses. The experimental BALB/c model of cutaneous leishmaniasis was used in this study. Mice were infected with L. major parasites and treated with three in vitro active tyrosyl esters derivatives. Among these tested tyrosylcaprate (TyC) compounds, only TyC10 exhibited an in vivo anti-leishmanial activity, when injected sub-cutaneously (s.c.). TyC10 treatment of L. major-infected BALB/c mice resulted in a decrease of lesion development and parasite load. TyC10 s.c. treatment of non-infected mice induced an imbalance in interferon γ/interleukin 4 (IFN-γ/IL-4) ratio cytokines towards a Th1 response. Our results indicate that TyC10 s.c. treatment improves lesions' healing and parasite clearance and may act on the cytokine balance towards a Th1 protective response by decreasing IL-4 and increasing IFN-γ transcripts. TyC10 is worthy of further investigation to uncover its mechanism of action that could lead to consider this molecule as a potential drug candidate.
Assuntos
Antiprotozoários/administração & dosagem , Fatores Imunológicos/administração & dosagem , Leishmania major/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Células Th1/imunologia , Tirosina/análogos & derivados , Tirosina/farmacologiaRESUMO
The present study investigated the kinetic and interfacial properties of two secreted phospholipases isolated from Tunisian vipers'venoms: Cerastes cerastes (CC-PLA2) and Macrovipera lebetina transmediterranea (MVL-PLA2). Results show that these enzymes have great different abilities to bind and hydrolyse phospholipids. Using egg-yolk emulsions as substrate at pH 8, we found that MVL-PLA2 has a specific activity of 1473U/mg at 37°C in presence of 1mM CaCl2. Furthermore the interfacial kinetic and binding data indicate that MVL-PLA2 has a preference to the zwitterionic phosphatidylcholine monolayers (PC). Conversely, CC-PLA2 was found to be able to hydrolyse preferentially negatively charged head group phospholipids (PG and PS) and exhibits a specific activity 9 times more important (13333U/mg at 60°C in presence of 3mM CaCl2). Molecular models of both CC-PLA2 and MVL-PLA2 3D structures have been built and their electrostatic potentials surfaces have been calculated. A marked anisotropy of the overall electrostatic charge distribution leads to a significantly difference in the dipole moment intensity between the two enzymes explaining the great differences in catalytic and binding properties, which seems to be governed by the electrostatic and hydrophobic forces operative at the surface of the two phospholipases.
Assuntos
Fosfolipases A2/química , Fosfolipídeos/química , Venenos de Víboras/enzimologia , Animais , Hidrólise , Cinética , Fosfolipases A2/isolamento & purificação , Venenos de Víboras/química , ViperidaeRESUMO
To improve biomass production and glucoamylase activity (GA) by Candida famata, culture conditions were optimized. A 2(3) full factorial design (FFD) with a response surface model was used to evaluate the effects and interactions of pH (X1 ), time of cultivation (X2 ), and starch concentration (X3 ) on the biomass production and enzyme activity. A total of 16 experiments were conducted toward the construction of an empiric model and a first-order equation. It was found that all factors (X1 , X2 , and X3 ) and their interactions were significant at a certain confidence level (P < 0.05). Using this methodology, the optimum values of the three tested parameters were obtained as follows: pH 6; time of cultivation 24 H and starch concentration 7 g/L, respectively. Our results showed that the starch concentration (X3) has significantly influenced both dependent variables, biomass production and GA of C. famata. Under this optimized medium, the experimental biomass production and GA obtained were 1.8 ± 0.54 g/L and 0.078 ± 0.012 µmol/L/Min, about 1.5- and 1.8-fold, respectively, higher than those in basal medium. The (R(2) ) coefficients obtained were 0.997 and 0.990, indicating an adequate degree of reliability in the model. Approximately 99% of validity of the predicted value was achieved.
Assuntos
Biomassa , Biotecnologia/métodos , Candida/metabolismo , Técnicas de Cultura/métodos , Glucana 1,4-alfa-Glucosidase/biossíntese , Glucana 1,4-alfa-Glucosidase/metabolismo , Análise de Variância , Candida/crescimento & desenvolvimento , Meios de Cultura/química , Fermentação , Concentração de Íons de Hidrogênio , Amido/metabolismoRESUMO
Snake venom l-amino acid oxidases are multifunctional enzymes that exhibited a wide range of pharmacological activities. Although it has been established that these activities are primarily caused by the H2O2 generated in the enzymatic reaction, the molecular mechanism, however, has not been fully investigated. In this work, LAAO interaction with cytoplasmic membranes using different cell types and Langmuir interfacial monolayers was evaluated. The Cerastes cerastes venom LAAO (CC-LAAO) did not exhibit cytotoxic activities against erythrocytes and peripheral blood mononuclear cells (PBMC). However, CC-LAAO caused cytotoxicity on several cancer cell lines and induced platelet aggregation in dose-dependent manner. Furthermore, the enzyme showed remarkable effect against Gram-positive and Gram-negative bacteria. These activities were inhibited on the addition of catalase or substrate analogs, suggesting that H2O2 liberation× is required for these effects. Binding studies revealed that CC-LAAO binds to the cell surface and enables the production of highly localized concentration of H2O2 in or near the binding interfaces. On another hand, the interaction of CC-LAAO with a mimetic phospholipid film was evaluated, for the first time, using a monomolecular film technique. Results indicated that phospholipid/CC-LAAO interactions are not involved in their binding to membrane and in their pharmacological activities.
Assuntos
Membrana Celular/metabolismo , L-Aminoácido Oxidase/química , L-Aminoácido Oxidase/metabolismo , Venenos de Serpentes/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Dano ao DNA , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Membrana Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/metabolismo , Hemólise/efeitos dos fármacos , Humanos , L-Aminoácido Oxidase/isolamento & purificação , L-Aminoácido Oxidase/toxicidade , Agregação Plaquetária/efeitos dos fármacos , Ligação Proteica , RatosRESUMO
Embryo cryopreservation is an essential tool in assisted reproduction. The option to freeze gametes and embryos provides unique possibilities for patients with various indications. After a review on some of the technical details of embryo freezing the idea of vitrification compared to slow freezing is discussed. It is recognized that the slow freezing technique is still overwhelmingly applied in most human in vitro fertilization (IVF) centers, but there is mounting evidence demonstrating the benefit of vitrification. Theoretical and practical examples are now sufficient to convince the embryologist that the time has arrived to switch to the vitrification technique. We report our experience that is the first Tunisian live birth following embryo vitrification at the blastocyst stage, collected at the military hospital of Tunis-Tunisia. A 29-year-old woman presented a primary infertility of 3 years of male origin. IVF with intra-cytoplasmic spermatozoid injection ICSI has been indicated. 7 blastocysts were obtained at fifth day. Two of them were replaced and ended in terminated pregnancy at 6AW. Vitrification method is a procedure which is to immerse the embryos directly into liquid nitrogen at -196 ° C. thereby achieving descents temperature of about -2000 ° C per minute within a secure glitter. The kit used in our laboratory is "irvine scientific" with glitter cryobiocystem. Six months later 2 blastocysts were devitrified in February 2012 and after replacement provided a normal progress pregnancy, delivery by caesarean section of a newborn male in good health.
Assuntos
Criopreservação/métodos , Técnicas de Cultura Embrionária , Adulto , Feminino , Fertilização in vitro , Humanos , Recém-Nascido , Nascido Vivo , Masculino , Gravidez , Tunísia , VitrificaçãoRESUMO
Recombinant DNA methods are being widely used to express proteins in both prokaryotic and eukaryotic cells for both fundamental and applied research purposes. Expressed protein must be well characterized to be sure that it retains the same properties as the native one, especially when expressed protein will be used in the pharmaceutical field. In this aim, interfacial and kinetic properties of native, untagged recombinant and tagged recombinant forms of a pancreatic lipase were compared using the monomolecular film technique. Turkey pancreatic lipase (TPL) was chosen as model. A kinetic study on the dependence of the stereoselectivity of these three forms on the surface pressure was performed using three dicaprin isomers spread in the form of monomolecular films at the air-water interface. The heterologous expression and the N-His-tag extension were found to modify the pressure preference and decrease the catalytic hydrolysis rate of three dicaprin isomers. Besides, the heterologous expression was found to change the TPL regioselectivity without affecting its stereospecificity contrary to the N-tag extension which retained that regioselectivity and changed the stereospecificity at high surface pressures. The study of parameters, termed Recombinant expression Effects on Catalysis (REC), N-Tag Effects on Catalysis (TEC), and N-Tag and Recombinant expression Effects on Catalysis (TREC) showed that the heterologous expression effects on the catalytic properties of the TPL were more deleterious than the presence of an N-terminal tag extension.
Assuntos
Proteínas Aviárias/química , Lipase/química , Pichia/metabolismo , Proteínas Aviárias/biossíntese , Proteínas Aviárias/genética , Diglicerídeos/química , Expressão Gênica , Hidrólise , Cinética , Lipase/biossíntese , Lipase/genética , Pâncreas/enzimologia , Pressão , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Especificidade por Substrato , TurquiaRESUMO
Ascorbyl lipophilic derivatives (Asc-C2 to Asc-C(18:1)) were synthesized in a good yield using lipase from Staphylococcus xylosus produced in our laboratory and immobilized onto silica aerogel. Results showed that esterification had little effect on radical-scavenging capacity of purified ascorbyl esters using DPPH assay in ethanol. However, long chain fatty acid esters displayed higher protection of target lipids from oxidation. Moreover, compared to ascorbic acid, synthesized derivatives exhibited an antibacterial effect. Furthermore, ascorbyl derivatives were evaluated, for the first time, for their antileishmanial effects against visceral (Leishmania infantum) and cutaneous parasites (Leishmania major). Among all the tested compounds, only Asc-C10, Asc-C12, and Asc-C(18:1) exhibited antileishmanial activities. The interaction of ascorbyl esters with a phospholipid monolayer showed that only medium and unsaturated long chain (Asc-C10 to Asc-C(18:1)) derivative esters were found to interact efficiently with mimetic membrane of leishmania. These properties would make ascorbyl derivatives good candidates to be used in cosmetic and pharmaceutical lipophilic formulations.
Assuntos
Ácido Ascórbico/metabolismo , Ácido Ascórbico/farmacologia , Leishmania infantum/efeitos dos fármacos , Antibacterianos , Antioxidantes , Ácido Ascórbico/química , Emulsificantes , Esterificação , Ésteres/química , Ésteres/metabolismo , Ácidos Graxos/metabolismo , Lipase/metabolismo , Lipídeos , Testes de Sensibilidade Microbiana , Staphylococcus/enzimologiaRESUMO
A new L-amino acid oxidase (LAAO) from Cerastes cerastes snake venom, named CC-LAAO, was purified to homogeneity using a combination of size-exclusion, ion-exchange and affinity chromatography. CC-LAAO is a homodimeric glycosylated flavoprotein with a molecular mass around 58 kDa under reducing conditions and about 115 kDa in its native form when analyzed by SDS-PAGE and gel filtration chromatography, respectively. This enzyme displayed a Michaelis-Menten behavior with an optimal pH at 7.8. However, unlike known SV-LAAOs which display their maximum activity at 37 °C, CC-LAAO has an optimal temperature at 50 °C. Kinetic studies showed that the enzyme displayed high specificity towards hydrophobic L-amino acids. The best substrates were L-Phe, L-Met and L-Leu. CC-LAAO activity was inhibited by the substrate analog N-acetyl tryptophan. The N-terminal amino acid sequence of this protein was determined by automated Edman degradation. The CC-LAAO cDNA was cloned from the venom gland total RNA preparation. The cDNA sequence contained an open-reading frame (ORF) of 1551-bp, which encoded a protein of 516 amino acids comprising a signal peptide of 18 amino acids and 498-residues mature protein. CC-LAAO sequence and its tertiary model shared high similarity with other snake venom LAAOs.
Assuntos
L-Aminoácido Oxidase/química , Venenos de Víboras/química , Sequência de Aminoácidos , Sequência de Bases , Cromatografia de Afinidade , Cromatografia em Gel , Cromatografia por Troca Iônica , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Glicosilação , Cinética , L-Aminoácido Oxidase/isolamento & purificação , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de Proteína , Especificidade por SubstratoRESUMO
A lipolytic activity was located in the scorpion venom glands (telsons), from which a phospholipase A2 (Sm-PLVG) was purified. Like known phospholipases A2 from scorpion venom, which are 14-18 kDa proteins, the purified Scorpio maurus-Phospholipase from Venom Glands (Sm-PLVG) has a molecular mass of 17 kDa containing long and short chains linked by disulfide bridge. It has a specific activity of 5500 U/mg measured at 47 °C and pH 8.5 using phosphatidylcholine as a substrate in presence of 8 mM NaTDC and 12 mM CaCl2. The NH2-terminal amino acid sequences of the purified Sm-PLVG showed similarities with those of long and short chains of some previously purified phospholipases from venom scorpions. Moreover, the Sm-PLVG exhibits hemolytic activity toward human, rabbit or rat erythrocytes. This hemolytic activity was related to its ability to interact with phospholipids' monolayer at high surface pressure. These properties are similar to those of phospholipases isolated from snake venoms.
Assuntos
Hemolíticos/química , Fosfolipases A2/química , Venenos de Escorpião/enzimologia , Escorpiões/química , Animais , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Eritrócitos/efeitos dos fármacos , Hemolíticos/isolamento & purificação , Hemolíticos/toxicidade , Humanos , Concentração de Íons de Hidrogênio , Cinética , Fosfolipases A2/isolamento & purificação , Fosfolipases A2/toxicidade , Coelhos , RatosRESUMO
A lipolytic activity was located in the chicken uropygial glands, from which a carboxylesterase (CUE) was purified. Pure CUE has an apparent molecular mass of 50 kDa. The purified esterase displayed its maximal activity (200 U/mg) on short-chain triacylglycerols (tributyrin) at a temperature of 50°C. No significant lipolytic activity was found when medium chain (trioctanoin) or long chain (olive oil) triacylglycerols were used as substrates. The enzyme retained 75% of its maximal activity when incubated during 2h at 50°C. The NH(2)-terminal amino acid sequence showed similarities with the esterase purified recently from turkey pharyngeal tissue. Esterase activity remains stable after its incubation during 30 min in presence of organic solvents such as hexane or butanol. CUE is a serine enzyme since it was inactivated by phenylmethanesulphonyl fluoride (PMSF), a serine-specific inhibitor. The purified enzyme, which tolerates the presence of some organic solvent and a high temperature, can be used in non-aqueous synthesis reactions. Hence, the uropygial esterase immobilised onto CaCO(3) was tested to produce the isoamyl and the butyl acetate (flavour esters). Reactions were performed at 50°C in presence of hexane. High synthesis yields of 91 and 67.8% were obtained for isoamyl and butyl acetate, respectively.
Assuntos
Esterases/química , Esterases/isolamento & purificação , Ésteres/síntese química , Sequência de Aminoácidos , Animais , Galinhas , Ativação Enzimática/efeitos dos fármacos , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Hidrólise , Lipólise , Dados de Sequência Molecular , Solventes/química , Temperatura , Compostos de Tosil/farmacologia , Compostos de Vinila/químicaRESUMO
BACKGROUND: Preparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants. RESULTS: A large series of tyrosyl esters (TyC2 to TyC18:1) with increasing lipophilicity was synthesized in a good yield using lipase from Candida antarctica (Novozyme 435). Spectroscopic analyses of purified esters showed that the tyrosol was esterified on the primary hydroxyl group. Synthetized compounds were evaluated for either their antimicrobial activity, by both diffusion well and minimal inhibition concentration (MIC) methods, or their antileishmanial activity against Leishmania major and Leishmania infantum parasite species.Among all the tested compounds, our results showed that only TyC8, TyC10 and TyC12 exhibited antibacterial and antileishmanial activities. When MIC and IC50 values were plotted against the acyl chain length of each tyrosyl derivative, TyC10 showed a parabolic shape with a minimum value. This nonlinear dependency with the increase of the chain length indicates that biological activities are probably associated to the surfactant effectiveness of lipophilic derivatives. CONCLUSION: These results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries.
Assuntos
Antibacterianos/síntese química , Antiprotozoários/síntese química , Ésteres/síntese química , Ácidos Graxos/síntese química , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/síntese química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Ésteres/isolamento & purificação , Ésteres/farmacologia , Ácidos Graxos/isolamento & purificação , Ácidos Graxos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Concentração Inibidora 50 , Leishmania/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Álcool Feniletílico/isolamento & purificação , Álcool Feniletílico/farmacologiaRESUMO
BACKGROUND: Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. RESULTS: Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50 °C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30 °C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h. CONCLUSIONS: Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.
Assuntos
Enzimas Imobilizadas/metabolismo , Álcoois Graxos/metabolismo , Proteínas Fúngicas/metabolismo , Lipase/metabolismo , Óleos de Plantas/metabolismo , Rhizopus/enzimologia , Ceras/metabolismo , Análise de Variância , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Enzimas Imobilizadas/química , Ésteres/química , Ésteres/metabolismo , Álcoois Graxos/química , Proteínas Fúngicas/química , Lipase/química , Análise Multivariada , Óleo de Palmeira , Óleos de Plantas/química , Análise de Regressão , Temperatura , Ceras/químicaRESUMO
AIM: Transversal study during hospital allergology visit which aim is to evaluate asthma control levels in Tunisia. METHODS: Questionnaire issue of global initiative for asthma (GINA) guidelines. RESULTS: 400 asthmatics were included (70% of women and 30% men), aged 32 +/- 11 years old. Asthma was intermittent in 43% of patients, mild persistant (27%), moderate (14%) and severe in 16% of patients. Daytime symptoms were observed in 56% of cases, nocturnal symptoms in 40%, exacerbations in 39% of cases, activities limitation in 44% of cases and need of rescue treatment in 56%. Controller medications were used in 63% of patients. Inhaled Glucocorticosteroids were used in 90% of patients with persistent asthma. Subjective self evaluation of asthma showed that 83% of patients felled better with treatment, whereas, asthma objective control was obtained only in 10% of them. For the rest, asthma was partly controlled in 35% of patients and uncontrolled in 55%. College and professional absenteeism was observed in 60% of cases, with a mean of 1 to 5 days per month. Control factors seem to be young age, non smoker status and mild persistent asthma. CONCLUSION: Although GINA 2006 guidelines and treatment progress, an important rate of asthmatics (90%) continue to present symptoms, underuse their treatment and overestimate control level of their disease.
Assuntos
Asma/tratamento farmacológico , Adolescente , Corticosteroides/uso terapêutico , Adulto , Antiasmáticos/uso terapêutico , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , TunísiaRESUMO
BACKGROUND AND OBJECTIVES: Studies on exercise-induced bronchoconstriction (EIB) in team sports are lacking. The aim of this study was to screen for EIB among amateur teenage football players in Tunisia and to compare EIB prevalence between regions. METHODS: One hundred ninety-six male football players (mean age [SD], 13.5 [0.5] yrs), practicing in three different cities of Tunisia (Tunis, Sousse and Sfax), underwent an outdoor free run of 7 minutes. Forced expiratory volume in one second (FEV subset1) was recorded prior to and at 0, 3, 5, 10, 15, 20 and 30 minutes after the run. Players were screened for EIB positivity defined as a greater than 10% decline in FEV subset1 from the resting value at any timepoint. RESULTS: FEV1 decreased more than 10% in 30% of the players. EIB positivity was more common in Sfax (15.8%) than in Tunis (7.7%) (P=.03). Air humidity during the study was higher in Tunis. CONCLUSION: EIB is prevalent among amateur teenage football players in Tunisia. The prevalence differs between regions and seems to be dependent on air humidity levels.