Mounir Traikia - Academia.edu (original) (raw)

Papers by Mounir Traikia

Research paper thumbnail of Asymmetrical Membranes and Surface Tension

Biophysical Journal, Sep 1, 2002

Research paper thumbnail of NMR metabolite quantification of a synthetic urine sample: an inter-laboratory comparison of processing workflows

Metabolomics, Jul 7, 2023

Research paper thumbnail of Cloud metabolomics-Response to cold shock in bacteria originating from clouds

HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2013

Research paper thumbnail of Towards NMR 1D and 2D targeted annotation from reference matrices

HAL (Le Centre pour la Communication Scientifique Directe), Jun 9, 2015

Research paper thumbnail of 2-Aminobenzothiazole degradation by free and Ca-alginate immobilized cells of Rhodococcus rhodochrous

HAL (Le Centre pour la Communication Scientifique Directe), 2009

Research paper thumbnail of Complementarity of NMR and MS methods in metabolome analysis of dairy cows’ urine

HAL (Le Centre pour la Communication Scientifique Directe), May 10, 2013

Research paper thumbnail of Cyclodextrins Allow the Combination of Incompatible Vancomycin and Ceftazidime into an Ophthalmic Formulation for the Treatment of Bacterial Keratitis

International Journal of Molecular Sciences, Sep 29, 2021

Research paper thumbnail of Spot urine collection: A valid alternative to total urine collection for metabolomic studies in dairy cattle

Journal of Dairy Science, 2022

Research paper thumbnail of Untargeted metabolomics approach to study polymers biodegradation by Rhodococcus Rhodochrous using LC-HRMS

HAL (Le Centre pour la Communication Scientifique Directe), Jun 27, 2022

Research paper thumbnail of Preliminary results of a MetaboHUB 2.0 inter-laboratory test on 1D 1H NMR metabolite quantification of a synthetic urine

HAL (Le Centre pour la Communication Scientifique Directe), Sep 5, 2022

Research paper thumbnail of PeakForest: a multi-platform digital infrastructure for interoperable metabolite spectral data and metadata management

Metabolomics

Introduction Accuracy of feature annotation and metabolite identification in biological samples i... more Introduction Accuracy of feature annotation and metabolite identification in biological samples is a key element in metabolomics research. However, the annotation process is often hampered by the lack of spectral reference data in experimental conditions, as well as logistical difficulties in the spectral data management and exchange of annotations between laboratories. Objectives To design an open-source infrastructure allowing hosting both nuclear magnetic resonance (NMR) and mass spectra (MS), with an ergonomic Web interface and Web services to support metabolite annotation and laboratory data management. Methods We developed the PeakForest infrastructure, an open-source Java tool with automatic programming interfaces that can be deployed locally to organize spectral data for metabolome annotation in laboratories. Standardized operating procedures and formats were included to ensure data quality and interoperability, in line with international recommendations and FAIR principles....

Research paper thumbnail of Cyclodextrins Allow the Combination of Incompatible Vancomycin and Ceftazidime into an Ophthalmic Formulation for the Treatment of Bacterial Keratitis

International Journal of Molecular Sciences, 2021

Ceftazidime (CZ) and vancomycin (VA) are two antibiotics used to treat bacterial keratitis. Due t... more Ceftazidime (CZ) and vancomycin (VA) are two antibiotics used to treat bacterial keratitis. Due to their physical incompatibility (formation of a precipitate), it is not currently possible to associate both molecules in a single container for ophthalmic administration. We firstly characterized the incompatibility then investigated if 2-hydroxypropyl-beta (HPβCD) and 2-hydroxypropyl-gamma cyclodextrins (HPγCD) could prevent this incompatibility. The impact of pH on the precipitation phenomena was investigated by analysing the supernatant solution of the mixture using high performance liquid chromatography. A characterization of the inclusion of CZ with HPγCD using 1H nuclear magnetic resonance (NMR), and VA with HPβCD using 1H-NMR and a solubility diagram was performed. A design of experiment was built to determine the optimal conditions to obtain a formulation that had the lowest turbidity and particle count. Our results showed that VA and CZ form an equimolar precipitate below pH 7...

Research paper thumbnail of Pyruvate Aldolases Catalyze Cross-Aldol Reactions between Ketones: Highly Selective Access to Multi-Functionalized Tertiary Alcohols

Research paper thumbnail of Cloud Microorganisms, an Interesting Source of Biosurfactants

Surfactants and Detergents [Working Title], 2019

Research paper thumbnail of A first inventory of the labile biochemicals found in Avignon groundwater: can we identify potential bacterial substrates?

E3S Web of Conferences, 2019

Groundwater is a major source of water for irrigation of vegetables, especially in the Mediterran... more Groundwater is a major source of water for irrigation of vegetables, especially in the Mediterranean basin. Contamination of aquifer by pathogens has been responsible for numerous disease outbreaks worldwide. Several studies reported that groundwater dissolved organic matter (DOM) can serve as a source of carbon and energy for heterotrophic metabolism of pathogens. In this study, we aimed to investigate the DOM composition of groundwater collected at Avignon. Six liters of groundwater were filtered (0.2 µm) and freeze-dried following appropriate cleaning procedure. The bulk analyses of powder sample were performed using 1D and 2D nuclear magnetic resonance spectroscopy and liquid chromatography coupled with mass spectroscopy. Several components were found at concentrations around 1 µM and comprise: (i) humic and fulvic acids originated from land-derived material or soils and, (ii) various acids, esters and alcohols of different sizes including acetate, lactate and formate, these may...

Research paper thumbnail of Quality of antiepileptic drugs in sub-Saharan Africa: A study in Gabon, Kenya, and Madagascar

Epilepsia, Jan 12, 2018

Epilepsy is a major public health issue in low- and middle-income countries, where the availabili... more Epilepsy is a major public health issue in low- and middle-income countries, where the availability and accessibility of quality treatment remain important issues, the severity of which may be aggravated by poor quality antiepileptic drugs (AEDs). The primary objective of this study was to measure the quality of AEDs in rural and urban areas in 3 African countries. This cross-sectional study was carried out in Gabon, Kenya, and Madagascar. Both official and unofficial supply chains in urban and rural areas were investigated. Samples of oral AEDs were collected in areas where a patient could buy or obtain them. Pharmacological analytical procedures and Medicine Quality Assessment Reporting Guidelines were used to assess quality. In total, 102 batches, representing 3782 units of AEDs, were sampled. Overall, 32.3% of the tablets were of poor quality, but no significant difference was observed across sites: 26.5% in Gabon, 37.0% in Kenya, and 34.1% in Madagascar (P = .7). The highest pr...

Research paper thumbnail of Synthesis of Branched-Chain Sugars with a DHAP-Dependent Aldolase: Ketones are Electrophile Substrates of Rhamnulose-1-phosphate Aldolases

Angewandte Chemie (International ed. in English), Jan 4, 2018

Dihydroxyacetone phosphate (DHAP)-dependent rhamnulose aldolases display an unprecedented versati... more Dihydroxyacetone phosphate (DHAP)-dependent rhamnulose aldolases display an unprecedented versatility for ketones as electrophile substrates. We selected and characterized a rhamnulose aldolase from Bacteroides thetaiotaomicron (RhuABthet) to provide a proof of concept. DHAP was added as a nucleophile to several α-hydroxylated ketones used as electrophiles. This aldol addition was stereoselective and produced branched-chain monosaccharide adducts with a tertiary alcohol moiety. Several aldols were readily obtained in good to excellent yields (from 76 to 95 %). These results contradict the general view that aldehydes are the only electrophile substrates for DHAP-dependent aldolases and provide a new C-C bond-forming enzyme for stereoselective synthesis of tertiary alcohols.

Research paper thumbnail of l-Rhamnulose-1-phosphate and l-fuculose-1-phosphate aldolase mediated multi-enzyme cascade systems for nitrocyclitol synthesis

Journal of Molecular Catalysis B: Enzymatic, 2015

Research paper thumbnail of High-Resolution Spectra of Liposomes Using MAS NMR. The Case of Intermediate-Size Vesicles

Journal of Magnetic Resonance, 1997

Research paper thumbnail of Proton magic-angle spinning–NMR investigation of surfactant aqueous suspensions

Journal of Colloid and Interface Science, 2004

Research paper thumbnail of Asymmetrical Membranes and Surface Tension

Biophysical Journal, Sep 1, 2002

Research paper thumbnail of NMR metabolite quantification of a synthetic urine sample: an inter-laboratory comparison of processing workflows

Metabolomics, Jul 7, 2023

Research paper thumbnail of Cloud metabolomics-Response to cold shock in bacteria originating from clouds

HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2013

Research paper thumbnail of Towards NMR 1D and 2D targeted annotation from reference matrices

HAL (Le Centre pour la Communication Scientifique Directe), Jun 9, 2015

Research paper thumbnail of 2-Aminobenzothiazole degradation by free and Ca-alginate immobilized cells of Rhodococcus rhodochrous

HAL (Le Centre pour la Communication Scientifique Directe), 2009

Research paper thumbnail of Complementarity of NMR and MS methods in metabolome analysis of dairy cows’ urine

HAL (Le Centre pour la Communication Scientifique Directe), May 10, 2013

Research paper thumbnail of Cyclodextrins Allow the Combination of Incompatible Vancomycin and Ceftazidime into an Ophthalmic Formulation for the Treatment of Bacterial Keratitis

International Journal of Molecular Sciences, Sep 29, 2021

Research paper thumbnail of Spot urine collection: A valid alternative to total urine collection for metabolomic studies in dairy cattle

Journal of Dairy Science, 2022

Research paper thumbnail of Untargeted metabolomics approach to study polymers biodegradation by Rhodococcus Rhodochrous using LC-HRMS

HAL (Le Centre pour la Communication Scientifique Directe), Jun 27, 2022

Research paper thumbnail of Preliminary results of a MetaboHUB 2.0 inter-laboratory test on 1D 1H NMR metabolite quantification of a synthetic urine

HAL (Le Centre pour la Communication Scientifique Directe), Sep 5, 2022

Research paper thumbnail of PeakForest: a multi-platform digital infrastructure for interoperable metabolite spectral data and metadata management

Metabolomics

Introduction Accuracy of feature annotation and metabolite identification in biological samples i... more Introduction Accuracy of feature annotation and metabolite identification in biological samples is a key element in metabolomics research. However, the annotation process is often hampered by the lack of spectral reference data in experimental conditions, as well as logistical difficulties in the spectral data management and exchange of annotations between laboratories. Objectives To design an open-source infrastructure allowing hosting both nuclear magnetic resonance (NMR) and mass spectra (MS), with an ergonomic Web interface and Web services to support metabolite annotation and laboratory data management. Methods We developed the PeakForest infrastructure, an open-source Java tool with automatic programming interfaces that can be deployed locally to organize spectral data for metabolome annotation in laboratories. Standardized operating procedures and formats were included to ensure data quality and interoperability, in line with international recommendations and FAIR principles....

Research paper thumbnail of Cyclodextrins Allow the Combination of Incompatible Vancomycin and Ceftazidime into an Ophthalmic Formulation for the Treatment of Bacterial Keratitis

International Journal of Molecular Sciences, 2021

Ceftazidime (CZ) and vancomycin (VA) are two antibiotics used to treat bacterial keratitis. Due t... more Ceftazidime (CZ) and vancomycin (VA) are two antibiotics used to treat bacterial keratitis. Due to their physical incompatibility (formation of a precipitate), it is not currently possible to associate both molecules in a single container for ophthalmic administration. We firstly characterized the incompatibility then investigated if 2-hydroxypropyl-beta (HPβCD) and 2-hydroxypropyl-gamma cyclodextrins (HPγCD) could prevent this incompatibility. The impact of pH on the precipitation phenomena was investigated by analysing the supernatant solution of the mixture using high performance liquid chromatography. A characterization of the inclusion of CZ with HPγCD using 1H nuclear magnetic resonance (NMR), and VA with HPβCD using 1H-NMR and a solubility diagram was performed. A design of experiment was built to determine the optimal conditions to obtain a formulation that had the lowest turbidity and particle count. Our results showed that VA and CZ form an equimolar precipitate below pH 7...

Research paper thumbnail of Pyruvate Aldolases Catalyze Cross-Aldol Reactions between Ketones: Highly Selective Access to Multi-Functionalized Tertiary Alcohols

Research paper thumbnail of Cloud Microorganisms, an Interesting Source of Biosurfactants

Surfactants and Detergents [Working Title], 2019

Research paper thumbnail of A first inventory of the labile biochemicals found in Avignon groundwater: can we identify potential bacterial substrates?

E3S Web of Conferences, 2019

Groundwater is a major source of water for irrigation of vegetables, especially in the Mediterran... more Groundwater is a major source of water for irrigation of vegetables, especially in the Mediterranean basin. Contamination of aquifer by pathogens has been responsible for numerous disease outbreaks worldwide. Several studies reported that groundwater dissolved organic matter (DOM) can serve as a source of carbon and energy for heterotrophic metabolism of pathogens. In this study, we aimed to investigate the DOM composition of groundwater collected at Avignon. Six liters of groundwater were filtered (0.2 µm) and freeze-dried following appropriate cleaning procedure. The bulk analyses of powder sample were performed using 1D and 2D nuclear magnetic resonance spectroscopy and liquid chromatography coupled with mass spectroscopy. Several components were found at concentrations around 1 µM and comprise: (i) humic and fulvic acids originated from land-derived material or soils and, (ii) various acids, esters and alcohols of different sizes including acetate, lactate and formate, these may...

Research paper thumbnail of Quality of antiepileptic drugs in sub-Saharan Africa: A study in Gabon, Kenya, and Madagascar

Epilepsia, Jan 12, 2018

Epilepsy is a major public health issue in low- and middle-income countries, where the availabili... more Epilepsy is a major public health issue in low- and middle-income countries, where the availability and accessibility of quality treatment remain important issues, the severity of which may be aggravated by poor quality antiepileptic drugs (AEDs). The primary objective of this study was to measure the quality of AEDs in rural and urban areas in 3 African countries. This cross-sectional study was carried out in Gabon, Kenya, and Madagascar. Both official and unofficial supply chains in urban and rural areas were investigated. Samples of oral AEDs were collected in areas where a patient could buy or obtain them. Pharmacological analytical procedures and Medicine Quality Assessment Reporting Guidelines were used to assess quality. In total, 102 batches, representing 3782 units of AEDs, were sampled. Overall, 32.3% of the tablets were of poor quality, but no significant difference was observed across sites: 26.5% in Gabon, 37.0% in Kenya, and 34.1% in Madagascar (P = .7). The highest pr...

Research paper thumbnail of Synthesis of Branched-Chain Sugars with a DHAP-Dependent Aldolase: Ketones are Electrophile Substrates of Rhamnulose-1-phosphate Aldolases

Angewandte Chemie (International ed. in English), Jan 4, 2018

Dihydroxyacetone phosphate (DHAP)-dependent rhamnulose aldolases display an unprecedented versati... more Dihydroxyacetone phosphate (DHAP)-dependent rhamnulose aldolases display an unprecedented versatility for ketones as electrophile substrates. We selected and characterized a rhamnulose aldolase from Bacteroides thetaiotaomicron (RhuABthet) to provide a proof of concept. DHAP was added as a nucleophile to several α-hydroxylated ketones used as electrophiles. This aldol addition was stereoselective and produced branched-chain monosaccharide adducts with a tertiary alcohol moiety. Several aldols were readily obtained in good to excellent yields (from 76 to 95 %). These results contradict the general view that aldehydes are the only electrophile substrates for DHAP-dependent aldolases and provide a new C-C bond-forming enzyme for stereoselective synthesis of tertiary alcohols.

Research paper thumbnail of l-Rhamnulose-1-phosphate and l-fuculose-1-phosphate aldolase mediated multi-enzyme cascade systems for nitrocyclitol synthesis

Journal of Molecular Catalysis B: Enzymatic, 2015

Research paper thumbnail of High-Resolution Spectra of Liposomes Using MAS NMR. The Case of Intermediate-Size Vesicles

Journal of Magnetic Resonance, 1997

Research paper thumbnail of Proton magic-angle spinning–NMR investigation of surfactant aqueous suspensions

Journal of Colloid and Interface Science, 2004