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Dive into the research topics where Catherine Humeau is active.

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Featured researches published by Catherine Humeau.


Enzyme and Microbial Technology | 2016

Enzymatic modification of polysaccharides: Mechanisms, properties, and potential applications: A review

Nadine Karaki; Abdulhadi Aljawish; Catherine Humeau; Lionel Muniglia; Jordane Jasniewski

Polysaccharides are natural biopolymers found in almost all living organisms. They are used extensively in various industrial applications, such as food, adhesives, pharmaceuticals, and cosmetics. In many cases, their practical use is limited because of their weak solubility in neutral pH, their unsuitable hydrophilic/hydrophobic balance. In this context, chemical or enzymatic modification of their structure appears as a relevant way, to improve their properties, and thus to enlarge the field of their potential applications. Taking into account the reduction of the input energy and the environmental impact, and due to high specificity and selectivity properties, enzymatic bioprocesses have been investigated as attractive alternatives to toxic and non-specific chemical approaches. This review discusses the methods of enzymatic functionalization of four well-known polysaccharides, chitosan, cellulose, pectin and starch. Particular emphasis was placed on the methods, the reaction types and the enzymes implicated in the modification such as laccases, peroxidases lipases, tyrosinases, and transglutaminases. The impact of functionalization on the properties and the applications of polysaccharide derivatives were described.


Journal of Physical Chemistry B | 2010

Solubilities Inferred from the Combination of Experiment and Simulation. Case Study of Quercetin in a Variety of Solvents

Latifa Chebil; Christophe Chipot; Fabien Archambault; Catherine Humeau; Jean Marc Engasser; Mohamed Ghoul; François Dehez

A strategy to infer solubilities from the combination of experiment and all-atom simulations is presented. From a single experimental estimate, the solubility of a substrate can be predicted in various environments from the related free energies of solvation. In the case of quercetin, the methodology was shown to reproduce the experimental solubilities in chloroform, water, acetonitrile, acetone, and tert-amyl alcohol within 0.5 log unit. The reliability of the estimates is markedly correlated to the accuracy of the experimental measure and to both the accuracy and precision of the computed free energies of solvation.


Food Chemistry | 2015

Enzymatic production of bioactive docosahexaenoic acid phenolic ester

Mohamed H.H. Roby; Ahmad Allouche; Layal Dahdou; Vanessa Cristina de Castro; Paulo Henrique Alves da Silva; Brenda N. Targino; Marion Huguet; Cédric Paris; Françoise Chrétien; Rosa-Maria Guéant; Stéphane Desobry; Thierry Oster; Catherine Humeau

Docosahexaenoic acid (DHA) is increasingly considered for its health benefits. However, its use as functional food ingredient is still limited by its instability. In this work, we developed an efficient and solvent-free bioprocess for the synthesis of a phenolic ester of DHA. A fed-batch process catalyzed by Candida antarctica lipase B was optimised, leading to the production of 440 g/L vanillyl ester (DHA-VE). Structural characterisation of the purified product indicated acylation of the primary OH group of vanillyl alcohol. DHA-VE exhibited a high radical scavenging activity in acellular systems. In vivo experiments showed increased DHA levels in erythrocytes and brain tissues of mice fed DHA-VE-supplemented diet. Moreover, in vitro neuroprotective properties of DHA-VE were demonstrated in rat primary neurons exposed to amyloid-β oligomers. In conclusion, DHA-VE synergized the main beneficial effects of two common natural biomolecules and therefore appears a promising functional ingredient for food applications.


Food Chemistry | 2015

Oxidative stability of DHA phenolic ester

Mohamed H.H. Roby; Vanessa Cristina de Castro; Brenda N. Targino; Paulo Henrique Alves da Silva; Cécile Mangavel; Françoise Chrétien; Catherine Humeau; Stéphane Desobry

Docosahexaenoic acid vanillyl ester (DHA-VE) was synthesized from docosahexaenoic acid ethyl ester (DHA-EE) and vanillyl alcohol by a solvent-free alcoholysis process catalysed by Candida antarctica lipase B. Oxidative stability of pure DHA-VE and the crude reaction medium consisting of 45% DHA-VE and 55% DHA-EE were compared with that of DHA-EE under various storage conditions. Oxidation progress was followed by determination of conjugated dienes and FTIR measurements. Analyses showed that DHA-EE was rapidly oxidised under all storage conditions in comparison with DHA-VE and crude reaction medium, whatever the temperature and the storage time. The grafting of vanillyl alcohol appeared as a powerful way to stabilize DHA against oxidation. Thanks to their stability, both DHA-VE and the crude reaction medium, allowing the production of the ester, offer huge potential as functional ingredients.


Engineering in Life Sciences | 2018

An aminoacylase activity from Streptomyces ambofaciens catalyzes the acylation of lysine on α-position and peptides on N-terminal position

Lena Dettori; Florent Ferrari; Xavier Framboisier; Cédric Paris; Yann Guiavarc'h; Laurence Hotel; Arnaud Aymes; Pierre Leblond; Catherine Humeau; Romain Kapel; Isabelle Chevalot; Bertrand Aigle; Stéphane Delaunay

The presence of aminoacylase activities was investigated in a crude extract of Streptomyces ambofaciens ATCC23877. First activities catalyzing the hydrolysis of N‐α or ε‐acetyl‐L‐lysine were identified. Furthermore, the acylation of lysine and different peptides was studied and compared with results obtained with lipase B of Candida antarctica (CALB). Different regioselectivities were demonstrated for the two classes of enzymes. CALB was able to catalyze acylation only on the ε‐position whereas the crude extract from S. ambofaciens possessed the rare ability to catalyze the N‐acylation on the α‐position of the lysine or of the amino‐acid in N‐terminal position of peptides. Two genes, SAM23877_1485 and SAM23877_1734, were identified in the genome of Streptomyces ambofaciens ATCC23877 whose products show similarities with the previously identified aminoacylases from Streptomyces mobaraensis. The proteins encoded by these two genes were responsible for the major aminoacylase hydrolytic activities. Furthermore, we show that the hydrolysis of N‐α‐acetyl‐L‐lysine could be attributed to the product of SAM23877_1734 gene.


Process Biochemistry | 2018

Molecular rules for selectivity in lipase-catalysed acylation of lysine

Lena Dettori; Christian Jelsch; Stéphane Delaunay; Xavier Framboisier; Isabelle Chevalot; Catherine Humeau

Abstract The selectivity of l -lysine acylation by lauric acid catalysed by Candida antarctica lipase B (CALB) was investigated combining experimental and theoretical methodologies. Experiments showed the near-exclusive acylation of lysine e-amino group; only traces of product resulting from the acylation of lysine α-amino group were observed fleetingly. Molecular modelling simulations were performed aiming to understand the molecular rules for selectivity. Flexible docking simulations combined with structural investigations into lysine/CALB binding modes also suggested the preferential acylation of the lysine e-amino group without, however, excluding the acylation of the lysine α-amino group. Electrostatic interaction energy between lysine and the residues covering the catalytic cavity was calculated in order to understand the discrimination between the two lysine amino groups. Key interactions with the polar region covering the catalytic triad were identified and a plausible explanation for selectivity was proposed.


Data in Brief | 2018

Enzymatic synthesis of geranyl acetate in packed bed reactor in supercritical carbon dioxide under various pressure-temperature conditions and reactor configurations

Mohamed Chafik Bourkaib; Harifeno Randriamalala; Lena Dettori; Catherine Humeau; Stéphane Delaunay; Isabelle Chevalot; Yann Guiavarc'h

Data in this paper describes the catalytic performances, expressed in terms of conversion %, of geraniol and acetic acid to geranyl acetate, using the immobilized lipase B from Candida antarctica in packed bed reactors (PBR) using supercritical CO2 as a solvent. Readers will find data related to different Figures or equations of the article as well as supplementary data that will help to make the difference between flowrates of CO2 in a liquid state and corresponding flowrates of supercritical CO2 for various CO2 pressure and temperature combinations.


Process Biochemistry | 2006

Enzymatic acylation of flavonoids

Latifa Chebil; Catherine Humeau; Aude Falcimaigne; Jean-Marc Engasser; Mohamed Ghoul


Journal of Chemical & Engineering Data | 2007

Solubility of Flavonoids in Organic Solvents

Latifa Chebil; Catherine Humeau; Julie Anthoni; François Dehez; † and Jean-Marc Engasser; Mohamed Ghoul


Journal of Agricultural and Food Chemistry | 2007

Enzymatic acylation of flavonoids : Effect of the nature of the substrate, origin of lipase, and operating conditions on conversion yield and regioselectivity

Latifa Chebil; Julie Anthoni; Catherine Humeau; Christine Gérardin; Jean-Marc Engasser; Mohamed Ghoul

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