Papers by Abdulhadi Aljawish
L'oxydation de l'acide férulique et de son ester (le férulate d'éthyle) par la laccas... more L'oxydation de l'acide férulique et de son ester (le férulate d'éthyle) par la laccase de Myceliophtora thermophila a été étudiée en milieu aqueux et dans des conditions expérimentales douces (30 °C et pH 7,5) afin de synthétiser de nouvelles molécules naturelles grâce à un procédé vert. L'oxydation enzymatique a permis l'obtention d'intermédiaires colorés pour l'acide férulique et incolores pour le férulate d'éthyle. En outre, le férulate d'éthyle a été plus rapidement totalement oxydé que l'acide férulique. De plus, cette procédure a abouti à des produits majoritairement dimériques avec MM = 443 g/mol et MM = 386 g/mol pour le férulate d'éthyle et l'acide férulique, respectivement. Les nouvelles molécules synthétisées ont présenté des propriétés antioxydantes importantes avec de faibles propriétés antibactériennes et cytotoxiques. En présence du chitosane insoluble dans le milieu réactionnel, la laccase a été protégée de l'inhibi...
Food contact materials (FCM) represent a major economic issue and a large field of innovation. Fo... more Food contact materials (FCM) represent a major economic issue and a large field of innovation. Food packaging production must be in compliance with the European Regulation 1935/2004: the third article specifies that FCM must not transfer their constituents to food in quantities which could endanger human health under normal or foreseeable conditions of use. Indeed, these materials are not inert and, in addition to started substances, Non-Intentionally Added Substances (NIAS) are able to be released into the food. NIAS can be contaminants from recycled materials, impurities, synthetic residues, new substances formed along the packaging production chain… Then, NIAS could represent a larget part of migrating substances which are not risk assessed, some being unpredictabled (Grob et al., 2006 ; Skejevrak et al., 2005). The European Regulation 10/2011 on plastic materials, multilayers and articles intended to come into contact with food regulates NIAS. It requires that the notion of the ...
Energies
The environmental context causes the use of renewable energy to increase, with the aim of finding... more The environmental context causes the use of renewable energy to increase, with the aim of finding alternatives to fossil-based products such as fuels. Biodiesel, an alternative to diesel, is now a well-developed solution, and its production from renewable resources makes it perfectly suitable in the environmental context. In addition, it is biodegradable, non-toxic and has low greenhouse gas emissions: reduced about 85% compared to diesel. However, the feedstock used to produce biodiesel competes with agriculture and the application of chemical reactions is not advantageous with a “green” process. Therefore, this review focuses only on bioprocesses currently taking an important place in the production of biodiesel and allow high yields, above 90%, and with very few produced impurities. In addition, the use of waste oils as feedstock, which now accounts for 10% of feedstocks used in the production of biodiesel, avoids competition with agriculture. To present a complete life-cycle of ...
Enzyme and Microbial Technology, 2017
Highlights The functionalization of pectin with phenols was performed in the presence of laccas... more Highlights The functionalization of pectin with phenols was performed in the presence of laccase Modified pectin contained five times more phenols than the native pectin The ferulic acid oxidation products were grafted onto pectin carboxyl groups
BioTech
The ferulic acid (FA)-oxidation by Myceliophthora thermophila laccase was performed in phosphate ... more The ferulic acid (FA)-oxidation by Myceliophthora thermophila laccase was performed in phosphate buffer at 30 °C and pH 7.5 as an eco-friendly procedure. LC-MS analysis showed that oxidation products were four dehydrodimers (P1, P2, P3, P5) at MM = 386 g/mol, two dehydrotetramers (P6, P7) at MM = 770 g/mol and one decarboxylated dehydrodimer (P4) at MM = 340 g/mol. Structural characterization showed that FA-dehydrodimers were symmetric for P1 and P5 while asymmetric for P2, P3 and P4. Physicochemical characterization showed that oxidation products presented a higher lipophilicity than that of FA. Moreover, symmetric dimers and tetra dimers had a higher melting point compared to FA and its asymmetric dimers. Antioxidant and anti-proliferative assessments indicated that enzymatic oligomerization increased antioxidant and anti-proliferative properties of oxidation products for P2, P3 and P6 compared to FA. Finally, this enzymatic process in water could produce new molecules, having goo...
Industrial & Engineering Chemistry, 1949
L'oxydation de l'acide ferulique et de son ester (le ferulate d'ethyle) par la laccas... more L'oxydation de l'acide ferulique et de son ester (le ferulate d'ethyle) par la laccase de Myceliophtora thermophila a ete etudiee en milieu aqueux et dans des conditions experimentales douces (30 °C et pH 7,5) afin de synthetiser de nouvelles molecules naturelles grâce a un procede vert. L'oxydation enzymatique a permis l'obtention d'intermediaires colores pour l'acide ferulique et incolores pour le ferulate d'ethyle. En outre, le ferulate d'ethyle a ete plus rapidement totalement oxyde que l'acide ferulique. De plus, cette procedure a abouti a des produits majoritairement dimeriques avec MM = 443 g/mol et MM = 386 g/mol pour le ferulate d'ethyle et l'acide ferulique, respectivement. Les nouvelles molecules synthetisees ont presente des proprietes antioxydantes importantes avec de faibles proprietes antibacteriennes et cytotoxiques. En presence du chitosane insoluble dans le milieu reactionnel, la laccase a ete protegee de l'inhibi...
■ The grafting of oxidized phenols onto chitosan increased its hydrophobic properties and improve... more ■ The grafting of oxidized phenols onto chitosan increased its hydrophobic properties and improved protein adsorption properties of chitosan derivative films. ■ HUVEC cells on chitosan derivative films demonstrated a well attachment and spread phenotype while they often did not spread and remained round on chitosan films. ■ Results showed improved cell adhesion on chitosan derivative films that was enhanced with the increasing of oxidized phenols grafted. ■ Almost similar protein adsorption and cell growth was obtained on FA and EF chitosan films.
A new glyco-phenol was produced by the coupling between glucosamine (Glu) and ferulic acid (FA) u... more A new glyco-phenol was produced by the coupling between glucosamine (Glu) and ferulic acid (FA) using Myceliophthora thermophila laccase as biocatalyst in mild conditions (distilled water and 30°C) as an environmentally friendly process. Results indicated that the enzymatic reaction created a new derivative (FA-Glu), produced from coupling between Glu and FA by covalent bonds. By the high production of (FA-Glu) derivative and its stability, the optimal ratio of (FA: Glu) was of (1:1) at optimal time reaction of 6 h. Under these optimal conditions, almost 55% of -NH2 groups on Glu were bound with FA-oxidation products. The new derivative showed higher hydrophobic character than Glu due to the presence of FA in its structure. LC-MS analysis showed that (FA-Glu) derivative exhibited a molecular mass at MM 713 g/mol containing one Glu-molecule and three FA-molecules after decarboxylation. Furthermore, the new derivative presented good antioxidant and anti-proliferative activities in com...
Food Additives & Contaminants: Part A
Biocatalysis and Agricultural Biotechnology
Food and Chemical Toxicology, 2017
This study aimed to evaluate the protective role of chitosan nanoparticles (COS-NPs) singly or pl... more This study aimed to evaluate the protective role of chitosan nanoparticles (COS-NPs) singly or plus quercetin (Q) against OTA-induced oxidative stress and renal genotoxicity. Twelve groups of male Sprague-Dawley rats were treated orally for 3 weeks included the control group, animals fed OTA-contaminated diet (3 mg/kg diet); COS-NPs-treated groups at low (140 mg/kg b.w.) or high (280 mg/kg b.w.) dose, Q-treated group (50 mg/kg b.w.), Q plus low or high dose of COS-NPs-treated groups and OTA plus Q and/or COS-NPs at the two tested doses-treated groups. The results indicated that COS-NPs were roughly rod in shape with average particle size of 200 nm and zeta potential 31.4 ± 2.8 mV. Animals fed OTA-contaminated diet showed significant changes in serum biochemical parameters, increase kidney MDA and DNA fragmentation and decreased GPx and SOD gene expression accompanied with severe histological changes. Q and/or COS-NPs at the two tested doses induced significant improvements in all tested parameters and succeeded to overcome these effects especially in the animals treated with Q plus the high dose of COS-NPs. It could be concluded that COS-NPs are promise candidate to enhance the antioxidant effect of Q and protect against the nephrotoxicity of OTA in high endemic areas.
Journal of Biotechnology, 2016
Carnosine (CAR) dipeptide was functionalized with ferulic acid (FA) as substrate using laccase fr... more Carnosine (CAR) dipeptide was functionalized with ferulic acid (FA) as substrate using laccase from Myceliophtora thermophila as biocatalyst. The enzymatic reaction was performed in aqueous medium under mild conditions (pH 7.5, 30°C) as an eco-friendly procedure. Results showed that this enzymatic process led to the synthesis of two new derivatives (P1, P2), from the coupling between CAR and FA derived products. Conditions allowing a high production of P1, P2 derivatives were determined with an optimal ratio of (FA: CAR) of (1:1.6) at optimal time reaction of 8 h. Under these optimal conditions, the coupling between CAR and FA-products was demonstrated, resulting in the decrease of-NH 2 groups (almost 50%) as quantified via derivatization. Due to the presence of FA in the structure of these new derivatives, they exhibited higher hydrophobic property than carnosine. Structural analyses by mass spectrometry showed that P1 and P2 (FA-CAR) derivatives exhibited the same molecular mass (MM 770 g/mol) containing one CAR-molecule and three FA-molecules but with different chemical structures. Furthermore, these derivatives presented improved antioxidant (almost 10 times) and anti-proliferative (almost 18 times) properties in comparison with CAR. Moreover, P1 derivative exhibited higher antioxidant and antiproliferative activities than P2 derivative, which confirmed the different structures of P1 and P2. These results suggested that the oxidized phenols coupling with carnosine is a promising process to enhance the CAR-properties.
Http Www Theses Fr, Jul 8, 2013
Enzyme and Microbial Technology, 2016
Biotechnology Progress, 2015
Environmental Toxicology and Pharmacology, 2016
This study aimed to prepare and characterize enzymatic modified chitosan nanoparticles (CSNPs) wi... more This study aimed to prepare and characterize enzymatic modified chitosan nanoparticles (CSNPs) with gallic acid (GA) or octyl gallate (OG) to optimize its potential in human application and to evaluate their protective role against ochrtoxin A (OTA) toxicity in catfish. The modified CSNPs have average size around 90nm with positive charge and high scavenging activity especially GA-CSNPs. In the in vivo study, catfish were divided into 8 groups and treated for 3 weeks as follow: the control group, OTA-treated group (1mg/kg b.w.), the groups treated with CSNPs, GA-CSNPs or OG-CSNPs (280mg/kg b.w.) anole or in combination with OTA. Blood, liver and kidney samples were collected for different analyses. OTA induced a significant biochemical disturbances accompanied with oxidative stress in liver and kidney, histological changes and increase DNA fragmentation in the kidney. Co-treatment with OTA plus the different CSNPs resulted in a significant improvement in all tested parameters and histological picture of the kidney. This improvement was more pronounced in the group treated with GA-CSNPs. It could be concluded that grafting of GA or its ester improved the properties of CSNPs. Moreover, GA-CSNPs showed strong scavenging properties than OG-CSNPs due to the blocking of carboxyl groups responsible of the scavenging activity in OG.
Toxicology Reports, 2015
The aims of the current study were to prepare chitosan nanoparticles (CNPs) and to evaluate its p... more The aims of the current study were to prepare chitosan nanoparticles (CNPs) and to evaluate its protective role alone or in combination with quercetin (Q) against AFB 1-induce cytotoxicity in rats. Male Sprague-Dawley rats were divided into 12 groups and treated orally for 4 weeks as follow: the control group, the group treated with AFB 1 (80 g/kg b.w.) in corn oil, the groups treated with low (140 mg/kg b.w.) or high (280 mg/kg b.w.) dose of CNPs, the group treated with Q (50 mg/kg b.w.), the groups treated with Q plus the low or the high dose of CNPs and the groups treated with AFB 1 plus Q and/or CNPs at the two tested doses. The results also revealed that administration of AFB 1 resulted in a significant increase in serum cytokines, Procollagen III, Nitric Oxide, lipid peroxidation and DNA fragmentation accompanied with a significant decrease in GPx I and Cu-Zn SOD-mRNA gene expression. Q and/or CNPs at the two tested doses overcome these effects especially in the group treated with the high dose of CNPs plus Q. It could be concluded that CNPs is a promise candidate as drug delivery enhances the protective effect of Q against the cytogenetic effects of AFB 1 in high endemic areas.
Uploads
Papers by Abdulhadi Aljawish