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BACKGROUND: The presence of some red blood cell (RBC) antigens may affect the preference for using type O blood in emergency situations because they may induce complex or multiple alloimmunization in special circumstances. METHODS: A subgroup of 77 type O blood Tunisian donors were genotyped for 19 common blood alleles using the single specific primer-polymerase chain reaction method. The statistical analysis was done using HaploView software. RESULTS: The study showed the dominance of the alleles RH*5, KEL*2, FY*2, and CO*1 and the absence of the homozygous state of the KEL*1 and CO*2 alleles. Furthermore, a complete linkage disequilibrium between the RH*2/RH*4 and RH*3/RH*5 loci and the FY*Null/FY*Exp and FY*A/FY*B loci was detected. Additionally, it seems that sensitization to MNS:3, FY:1, and RH:3 may constitute a potential factor for alloimmunization after transfusion with O blood type units: the probabilities of simple alloimmunizations are 24.5 per 100, 18.5 per 100, and 18 per 100, respectively. Multiple alloimmunization against RH:1;KEL:1 or RH:1;KEL:1;RH:3 phenotypes may occur, with probabilities of 7 per 1000 and 2 per 1000, respectively. CONCLUSION: Some O-type RBC units may contain blood with very immunogenic phenotypes, the use of which in an emergency requires great caution because it can be a step towards subsequent alloimmunization.
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Graft-versus-host disease (GVHD) is a potentially serious complication ofallogeneic hematopoietic stem cell transplantation (HSCT). Graft-contaminating T cells (donor T cells) arecrucial for the development ofGVHD since they are able to react against the recipient's antigens. In this study we aim toevaluatethepotentialassociation between the IVS3 + 17 T/C gene variation in the CD28 molecule, a T cells costimulatory factor, and the GVHD occurrence in a Tunisian group of recipients of allo-HSCTs. Results show that there is an association between the presence of this polymorphism and the occurrence of grades II-IV acute GVHD (OR: 2.470, I.C: 1.027-5.938, p = 0.043). As for the chronic GVHD, it seems that the studied gene variation has no impact on the occurrence of this complication, which appeared likely to be affected by the HSCT graft source (PBSC: peripheral blood stem cells) (OR: 5.141, I.C: 1.590-16.620, p = 0.006). Based on these data, we believe that the CD28 IVS3 + 17 T/C polymorphism is a significant factor in the pathogenesis of acute GVHD.
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BACKGROUND: In sports sciences, normative data serve as standards for specific physical performance attributes, enhancing talent identification within a specific population. The aim of this study was to provide standard data for Agility-15 m, Ball-15 m tests, and skill index, considering maturation level, specifically age at peak height velocity (PHV). The study also investigated the relationship between relative performances in these tests and anthropometrics, jumping (squat jump [SJ], countermovement jump [CMJ]), and sprinting abilities (S-5 m, S-10 m, S-20 m, S-30 m) in young soccer players. METHODS: The study involved 647 soccer players aged 11-18 years, categorized into three groups: pre-PHV, circum-PHV, and post-PHV. Statistical analysis was conducted using analysis of variance and Bonferroni post hoc testing to detect variations among maturation groups, and Pearson's correlation test to examine the relationship between factors. RESULTS: Agility-15 m and ball-15 m performances among maturity groups showed significant differences (p < 0.01). Significant correlations were identified in pre-PHV group, between lower limb length and Agility-15 m (r=-0.23, p < 0.05) and between height and Ball-15 m (r=-0.23, p < 0.05). In post-PHV group, there was a correlation between body fat percentage (BF %) and Agility-15 m (r = 0.17, p < 0.05) and Ball-15 m (r = 0.21, p < 0.05). In all maturity groups, there were significant correlations between agility and sprint tests (S-5 m, S-10 m, S-20 m, and S-30 m) and muscle power (SJ and CMJ). CONCLUSION: The study revealed that both speed and lower limb power significantly influence agility in young soccer players, providing valuable insights for coaches and practitioners to create tailored training plans and interventions for different age groups and maturity levels.
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This study investigates how the COVID-19 outbreak has shaped the volatility spillover between oil and Gulf Cooperation Council (GCC) stock markets. Contagion analysis is conducted by implementing a vector error correction (VECM) asymmetric BEKK model, wherein both cointegration and asymmetric features are considered. Financial market uncertainty caused by the recent health crisis is captured using Baker et al.'s (2020) newly developed infectious disease tracker. Our results indicate a significant discrepancy in the GCC group, as shock and volatility linkages between oil and equities are more apparent for some countries but not for others. The estimated VECM-asymmetric BEKK model reveals cross-market asymmetric spillover effects only in Kuwait, Qatar, and Saudi Arabia. We report that the global pandemic has strongly affected crude oil market volatility, while the GCC region seems to be less affected by the emergence of the new infectious disease. Our findings underscore the diversification opportunities offered by Gulf equity markets to international investors.
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BACKGROUND: Minor histocompatibility antigens (mHAgs) are endogenous immunogenic peptides initially identified due to complications detected in several contexts of HLA geno-identical hematopoietic stem cell transplantation (HSCT). In this study, we chose to examine the molecular polymorphism of the mHAgs HA-8 and PANE1 in the Tunisian population. MATERIAL AND METHODS: This study was conducted on 150 healthy and unrelated individuals. The DNA extraction and Sequence-Specific Primers PCR (PCR-SSP) methods were used for the molecular genotyping of the selected SNPs: PUM3 (rs2173904) and CENPM (rs5758511). RESULTS: Our results show that, 94% of Tunisians are carriers of the PANE1R allele (immunogenic variant of the PANE1 mHAg) and 68% of Tunisians are carriers of the HA-8R allele (immunogenic variant of the HA-8 mHAg). Furthermore, this study shows that about 5% of the Tunisians are carrier of the PANE1R antigen and its HLA molecule of presentation (the PANE1R/HLA-A*0301 combination). However, only 2% of Tunisians are carrier of the HA-8R/HLA-A*0201 combination, that is, the HA8 immunogenic variant and its specific HLA molecule of presentation. CONCLUSION: Our results are close to those reported in Caucasian, Asiatic, and African populations, this may be explained by the historical events experienced by Tunisia for millennia. These results could be used for further clinical and anthropological studies.
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Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Humanos , Doença Enxerto-Hospedeiro/genética , Antígenos de Histocompatibilidade Menor/genética , Alelos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
INTRODUCTION AND IMPORTANCE: A bezoar is an agglutination of ingested materials forming an indigestible and insoluble mass inside the gastrointestinal tract. Trichobezoars formed by ingested hair are rare. The stomach tends to be the typical location. In some cases there is an extension to the duodenum, jejunum or even to the colon and it is called Rapunzel syndrome. CASE PRESENTATION: We present a case of an occlusion due to double trichobezoars in 17 years old woman who underwent an extraction by enterotomy and gastrotomy. CLINICAL DISCUSSION: Trichobezoar is a compact conglomeration of swallowed hair and makes up less than 6% of all bezoars. It appears in young women under 20 years of age who carry psychiatric or chronic metabolic diseases that can alter the behavioral balance. Physical examination is often poor in uncomplicated forms: forms without peritonitis or occlusion or hemorrhage or appendicitis or pancreatitis but it may reveal a well-limited, smooth, firm, and mobile epigastric mass. For uncomplicated forms or forms complicated by hemorrhage, the reference examination requested in the first line remains the esophagogastroduodenoscopy (EGD) which allows a dual role both diagnostic and therapeutic. Computed Tomography (CT) remains the preferred imaging modality requested urgently in case of an occlusion or peritonitis presentation. Endoscopic extraction represents the therapeutic approach for uncomplicated forms but surgical treatment remains the main therapeutic means of trichobezoar. CONCLUSION: Trichobezoars are rare and present both diagnostic and therapeutic challenge. Laparotomy remains the most successful surgical treatment although laparoscopy currently appears to have promising results in expert hands. A post-operative pscychologic management is essential to correct psychobehavioral disorders of patients to prevent recurrence.
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BACKGROUND: Grass pea (Laithyrus sativus L.) is a rustic plant whose seeds are rich in polyphenols and antioxidants, and it has been consumed as food by human beings since ancient times. This study was conducted in Italy between 2017and 2019 to evaluate, under field conditions, the stability of seed yield, biomass and 1000-seed weight (THS) and to assess the antioxidant composition and activity of 11 grass pea accessions. RESULTS: Analysis of variance revealed significant effects of the environment, accession and accession × environment (A × E) on the yield, above-ground biomass and THS. We found that the environment (year) and A × E explained 52.61% and 23.76% of the total seed yield variation, respectively. No relationship was observed between the yield and the total protein of seeds. Most grass pea accessions showed sensitivity to frost conditions that occurred in the third growing season. The total phenolic content ranged from 50.51 to 112.78 mg 100 g-1 seeds and antioxidant activity ranged from 0.576 to 0.898 mmol Trolox equivalents 100 g-1 seeds and from 0.91 to 1.6 mmol Fe2+ 100 g-1 seeds in 2,20-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power, respectively. Among the accessions, the 'Campi Flegrei' and 'di Castelcività' showed the best performance with the highest yield and stability, phenolic content and superior antioxidant activity. CONCLUSION: The results showed that the yield of grass pea was mainly influenced by different climate conditions. This variability in yield, phenolic content and antioxidant activity among different accessions could help breeders and farmers select high-performance accessions for cultivation. © 2020 Society of Chemical Industry.
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Lathyrus , Antioxidantes/análise , Genótipo , Humanos , Lathyrus/química , Pisum sativum/genética , Fenóis/análise , Sementes/química , Sementes/genéticaRESUMO
BACKGROUND: Several studies have shown that grain amaranth (Amaranthus spp.) is tolerant to abiotic stresses such as drought and salinity. Irrigation applied only during sensitive growth stages can stabilize yield and improve water use efficiency. Given the increasing frequency of salinity and drought stress in European countries and the scarcity of information on grain amaranth responses to combined salt and drought stress, an open field trial was carried out in Italy in order to evaluate the response of one accession of Amaranthus hypochondriacus to various irrigation strategies. RESULTS: Grain amaranth yield components were not negatively affected either by different irrigation volumes or by irrigation time. Some differences in seed yield were caused by water quality; salinity significantly reduced seed yield. The combined effect of irrigation time and irrigation volume significantly influenced seed yield. The quality of amaranth seeds was preserved; no significant differences due to simple or combined stresses were found during the three-year field experiment. CONCLUSIONS: The overall results from this study suggest that A. hypochondriacus can be cultivated in a more sustainable way compared to other protein crops, thus reducing water use and using saline water. It could be introduced to marginal European environments where traditional crops cannot be cultivated. © 2021 Society of Chemical Industry.
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Amaranthus , Produtos Agrícolas , Secas , Grão Comestível , Salinidade , SementesRESUMO
In a soilless long-term salt-stress experiment, we tested the differences between the commercial sweet pepper cultivar "Quadrato d'Asti" and the landrace "Cazzone Giallo" in the structure and function of PSII through the JIP test analysis of the fast chlorophyll fluorescence transients (OKJIP). Salt stress inactivated the oxygen-evolving complex. Performance index detected the stress earlier than the maximum quantum yield of PSII, which remarkably decreased in the long term. The detrimental effects of salinity on the oxygen evolving-complex, the trapping of light energy in PSII, and delivering in the electron transport chain occurred earlier and more in the landrace than the cultivar. Performance indexes decreased earlier than the maximum quantum yield of PSII. Stress-induced inactivation of PSII reaction centers reached 22% in the cultivar and 45% in the landrace. The resulted heat dissipation had the trade-off of a correspondent reduced energy flow per sample leaf area, thus an impaired potential carbon fixation. These results corroborate the reported higher tolerance to salt stress of the commercial cultivar than the landrace in terms of yield. PSII was more affected than PSI, which functionality recovered in the late of trial, especially in the cultivar, possibly due to heat dissipation mechanisms. This study gives valuable information for breeding programs aiming to improve tolerance in salt stress sensitive sweet pepper genotypes.
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Quinoa (Chenopodium quinoa Willd.) is one of the most popular emerging food crops in the Andean region. It is tolerant to environmental stresses and characterized by interesting nutritional traits. Thus, it has the potential to contribute to food and nutrition security in marginal environments. In this study, we conducted a systematic review integrated with a bibliometric analysis of cropping practices of quinoa under field conditions. The analysis is based on published data from the literature relating to the period 2000-2020. A total of 33 publications were identified, revealing that scientific research on the agronomic practices and performances of quinoa under field conditions is still limited. Africa, Asia, and Europe were the leading research production sites in this field and together provided over 81% of the total scientific production. There were no papers from the Australian continent. The number of papers screened dealing with tillage and weed control management was very limited. The keyword co-occurrence network analyses revealed that the main topics addressed in the scientific literature related to the effect of "variety" and "deficit irrigation", followed by "water quality", "fertilization", and "sowing date" on seed yield. Results from this study will permit us to identify knowledge gaps and limited collaboration among authors and institutions from different countries. Salinity, sowing density, and sowing date were the agronomic interventions affecting productive response the most.
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The identification and isolation of bioactive compounds are of great interest in the drug delivery field, despite being a difficult task. We describe here an innovative strategy for the identification of a new gastric lipase inhibitor from star anise for the treatment of obesity. After plant screening assays for gastric lipase inhibition, star anise was selected and investigated by bioactivity guided fractionation. MALDI-TOF mass spectrometry and peptide mass fingerprinting allowed the detection of an inhibitor covalently bound to the catalytic serine of gastric lipase. A mass-directed screening approach using UPLC-HRMS and accurate mass determination searching identified the flavonoid myricitrin-5-methyl ether (M5ME) as a lipase inhibitor. The inhibitory activity was rationalized based on molecular docking, showing that M5ME is susceptible to nucleophilic attack by gastric lipase. Overall, our data suggest that M5ME may be considered as a potential candidate for future application as a gastric lipase inhibitor for the treatment of obesity.
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Inibidores Enzimáticos/química , Illicium/química , Lipase/química , Extratos Vegetais/química , Estômago/enzimologia , Sítios de Ligação , Inibidores Enzimáticos/isolamento & purificação , Cinética , Espectrometria de Massas , Simulação de Acoplamento Molecular , Extratos Vegetais/isolamento & purificaçãoRESUMO
Unlike the synthetic surfactants, mono- and diacylglycerols have the advantage to be biodegradable and non-toxic. In the present work, the hydrolysis of lipid fraction by-products of refined vegetable oils was performed by Serratia sp. W3 lipase immobilized on CaCO3 by combined adsorption and precipitation. This support was selected out of four carriers as it exhibited the finest activity support (950 U/g) and the most satisfactory behavior at use. The immobilized preparation with CaCO3 was stable and active in the whole range of pH (4 to 9) and temperature (37 to 55°C), yielding a 75% degree of hydrolysis at optimal environmental conditions of pH 8.5 and temperature 55°C. Thin-layer chromatography, gas chromatography, and liquid chromatography methods were evaluated to determine the analytical characterization of hydrolysis products. For monoacylglycerols and diacylglycerol fractions identified in the samples, a novel approach by liquid chromatography method was employed, through a homemade linear retention index database and a dedicated software. The adopted approach allowed the use of basic instrumentation set-ups, without the need of sophisticated detectors, such as mass spectrometers. Thus, it could be an effective alternative to produce emulsifiers from cheap vegetable oils.
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Diglicerídeos/biossíntese , Lipase/metabolismo , Monoglicerídeos/biossíntese , Óleos de Plantas/química , Serratia/enzimologia , Produtos Vegetais/análise , Adsorção , Carbonato de Cálcio/química , Carbonato de Cálcio/metabolismo , Diglicerídeos/análise , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/química , Monoglicerídeos/análise , Tamanho da Partícula , Óleos de Plantas/metabolismo , Software , Propriedades de Superfície , TemperaturaRESUMO
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.
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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
The aim of this study is to search new anti-obesity and anti-diabetic agents from plant and spices crude extracts as alternative to synthetic drugs. The inhibitory effect of 72 extracts was evaluated, in vitro, on lipase and amylase activities. Aqueous extracts of cinnamon and black tea exhibited an appreciable inhibitory effect on pancreatic amylase with IC50 values of 18 and 87 µg, respectively. Aqueous extracts of cinnamon and mint showed strong inhibitory effects against pancreatic lipase with IC50 of 45 and 62 µg, respectively. The presence of bile salts and colipase or an excess of interface failed to restore the lipase activity. Therefore, the inhibition of pancreatic lipase, by extracts of spices and plants, belongs to an irreversible inhibition. Crude extract of cinnamon showed the strongest anti-lipase and anti-amylase activities which offer a prospective therapeutic approach for the management of diabetes and obesity.
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Amilases/metabolismo , Lipase/antagonistas & inibidores , Pâncreas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Especiarias/análise , Amilases/antagonistas & inibidores , Fármacos Antiobesidade/farmacologia , Cinnamomum zeylanicum/química , Hipoglicemiantes/farmacologia , Concentração Inibidora 50 , Lipase/metabolismo , Mentha/química , Pâncreas/enzimologiaRESUMO
The objective of this study was to evaluate the exopolysaccharide (EPS) production by Rhizobium leguminosarum cultivated in wastewater generated by oil companies (WWOC1 and WWOC2) and fish processing industry (WWFP). The results obtained in Erlenmeyer flasks indicated that the rhizobial strain grew well in industrial wastewater. Generally, wastewater composition affected the growth and the EPS production. WWFP allowed good bacterial growth similar to that obtained with the standard medium (YMB). During growth, various quantities of EPS were produced and yields varied depending on the media. Growing in YMB, EPS production did not exceed 9.7 g/L obtained after 72 h of growth. In wastewater, the maximum EPS value reached 11.1 g/L obtained with the fish processing wastewater, after 72 h of growth. The use of a mixture of the oil company wastewater (WWOC2) and the fish processing wastewater (WWFP) as culture medium affected not only the rhizobial strain growth, but also EPS production. The highest EPS (42.4 g/L, after 96 h of culture) was obtained using a ratio of WWFP and WWOC2 of 50:50 (v:v). Therefore, this work shows the ability of Rhizobium leguminosarum, growing in industrial wastewater as new economic medium, to produce EPS. This biopolymer could be applied in enormous biotechnological areas.
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Polissacarídeos Bacterianos/metabolismo , Rhizobium leguminosarum/crescimento & desenvolvimento , Rhizobium leguminosarum/metabolismo , Águas Residuárias/microbiologia , Indústria Alimentícia , Resíduos Industriais , Indústria de Petróleo e GásRESUMO
The objective of this study was to evaluate the exopolysaccharide (EPS) production by Rhizobium leguminosarum cultivated in wastewater generated by oil companies (WWOC1 and WWOC2) and fish processing industry (WWFP). The results obtained in Erlenmeyer flasks indicated that the rhizobial strain grew well in industrial wastewater. Generally, wastewater composition affected the growth and the EPS production. WWFP allowed good bacterial growth similar to that obtained with the standard medium (YMB). During growth, various quantities of EPS were produced and yields varied depending on the media. Growing in YMB, EPS production did not exceed 9.7 g/L obtained after 72 h of growth. In wastewater, the maximum EPS value reached 11.1 g/L obtained with the fish processing wastewater, after 72 h of growth. The use of a mixture of the oil company wastewater (WWOC2) and the fish processing wastewater (WWFP) as culture medium affected not only the rhizobial strain growth, but also EPS production. The highest EPS (42.4 g/L, after 96 h of culture) was obtained using a ratio of WWFP and WWOC2 of 50:50 (v:v). Therefore, this work shows the ability of Rhizobium leguminosarum, growing in industrial wastewater as new economic medium, to produce EPS. This biopolymer could be applied in enormous biotechnological areas.
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Polissacarídeos Bacterianos/metabolismo , Rhizobium leguminosarum/crescimento & desenvolvimento , Rhizobium leguminosarum/metabolismo , Águas Residuárias/microbiologia , Indústria Alimentícia , Resíduos Industriais , Indústria de Petróleo e GásRESUMO
Most industries in the world treat their wastewaters with a conventional coagulation-flocculation process using alum as coagulant, polyacrylamide (PAM) as flocculant and lime as coagulant aid. To reduce the use of chemical products in the process, experiments were conducted to substitute the PAM with cactus juice (CJ) as flocculant. From the obtained data, it was concluded that the substitution of PAM with CJ in the coagulation-flocculation process was very effective, compared with PAM. Depending on the wastewater's origin, the bioflocculant showed removal efficiencies of 83.3-88.7% for suspended solids (SS) and 59.1-69.1% for chemical oxygen demand (COD). Lime addition enhanced the coagulation-flocculation process in the presence of CJ similarly to the PAM with efficiencies greater than 90% for both SS and COD. The CJ powder's infrared (IR) spectrum showed the main functional groups present in PAM. It was concluded that CJ as a flocculant fits well with the definition of sustainability and it is appropriate for countries that have regions where cactuses grow naturally.
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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.
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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
Lipase production by Staphylococcus xylosus and Rhizopus oryzae was investigated using a culture medium based on a mixture of synthetic medium and supernatants generated from tuna by-products and Ulva rigida biomass. The proportion of the three medium components was optimized using the simplex-centroid mixture design method (SCMD). Results indicated that the experimental data were in good agreement with predicted values, indicating that SCMD was a reliable method for determining the optimum mixture proportion of the growth medium. Maximal lipase activities of 12.5 and 23.5 IU/mL were obtained with a 50:50 (v:v) mixture of synthetic medium and tuna by-product supernatant for Staphylococcus xylosus and Rhizopus oryzae, respectively. The predicted responses from these mixture proportions were also validated experimentally.
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Proteínas de Bactérias/biossíntese , Reatores Biológicos , Proteínas Fúngicas/biossíntese , Lipase/biossíntese , Modelos Estatísticos , Eliminação de Resíduos/métodos , Análise de Variância , Animais , Proteínas de Bactérias/análise , Proteínas de Bactérias/metabolismo , Meios de Cultura , Indústria de Processamento de Alimentos , Proteínas Fúngicas/análise , Proteínas Fúngicas/metabolismo , Resíduos Industriais , Lipase/análise , Lipase/metabolismo , Reprodutibilidade dos Testes , Projetos de Pesquisa , Rhizopus/química , Rhizopus/metabolismo , Staphylococcus/química , Staphylococcus/metabolismo , Atum , UlvaRESUMO
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.