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Michel T.,CNRS Institute of Organic and Analytical Chemistry | Destandau E.,CNRS Institute of Organic and Analytical Chemistry | Pecher V.,LVMH Recherche Parfums et Cosmetiques | Renimel I.,LVMH Recherche Parfums et Cosmetiques | And 3 more authors.
Separation and Purification Technology | Year: 2011

Butea monosperma (Lam.) Taubert (Synonym Butea frondosa; family Fabaceae) is a popular plant used in traditional medicine in the Indian continent. The brightly orange flowers of this plant are described with antioxidant potential. The aim of this study was to develop a bio-guided fractionation methodology in order to identify antioxidant biomarkers from B. monosperma flowers which could be used to ensure quality and efficiency of cosmetic products. The hydro-alcoholic extract of B. monosperma flowers was separated using a double Centrifugal Partition Chromatography (CPC) procedure. Presence and/or absence of specific molecule families were evaluated by High Performance Thin Layer Chromatography (HPTLC). The antioxidant activity was performed on each fraction to guide fractionation step. First CPC step separated the crude extract in three fractions of different polarities. The aqueous antioxidant fraction was then subjected to a second CPC separation leading to five sub-fractions. Butrin and isobutrin were isolated from the antioxidant sub-fraction and were highlighted as potential antioxidant marker in B. monosperma flowers. Their chemical structures were confirmed by UV, MS and NMR analyses. © 2011 Elsevier B.V. All rights reserved.

El Abdellaoui S.,CNRS Institute of Organic and Analytical Chemistry | Destandau E.,CNRS Institute of Organic and Analytical Chemistry | Toribio A.,CNRS Institute of Organic and Analytical Chemistry | Elfakir C.,CNRS Institute of Organic and Analytical Chemistry | And 5 more authors.
Analytical and Bioanalytical Chemistry | Year: 2010

Kalanchoe pinnata (Lam.) Pers. (syn. Bryophyllum pinnatum; family Crassulaceae) is a popular plant used in traditional medicine in many temperate regions of the world and particularly in South America. In Guyana, the leaves are traditionally used as an anti-inflammatory and antiseptic to treat coughs, ulcers, and sores. The purpose of this study was to implement a method for targeting and identifying molecules with antimicrobial activity, which could replace chemical preservatives in cosmetic applications. The leaves were extracted by a method based on pressurized liquid extraction (PLE), using different solvents. A study of antimicrobial activity and cytotoxicity tests were performed to select the most interesting extract. To isolate one or more active molecules, the selected crude extract was fractionated by centrifugal partition chromatography (CPC) and then antimicrobial activity and cytotoxicity of each fraction were tested under the same procedure. The last step consisted of identifying the main compounds in the most active fraction by LC-MS/MS. © 2010 Springer-Verlag.

Othman M.,University Paris - Sud | Desmaele D.,University Paris - Sud | Couvreur P.,University Paris - Sud | Vander Elst L.,University of Mons | And 8 more authors.
Organic and Biomolecular Chemistry | Year: 2011

A family of novel amphiphilic gadolinium chelates was successfully obtained by coupling the hydrophilic DOTA ligand [1,4,7,10-tetrakis(carboxymethyl)-1,4, 7,10-tetraazacyclododecane] to squalenoyl moieties. Thanks to the self-assembling properties of their squalenoyl lipophilic moieties, all these derivatives were able to form, without any adjuvant, micellar or liposome-like supramolecular nanoassemblies, endowed with high relaxivities (r1 = 15-22 mM-1 s-1 at 20 MHz and 37°C). The remarkably high payloads of Gd3+ ions reached 10 to 17 wt %. Moreover, one of these derivatives interacted with human serum albumin (HSA) forming mixed micelles, which induced a remarkable increase in relaxivity. Liposome-like structures were obtained when the Gd3+ complex of DOTA was coupled to two squalene units. These liposomal structures were characterized by a high loading of Gd3+ (about 74000 gadolinium ions per particle of 100 nm). The supramolecular architecture of these nano-objects has been investigated by electron microscopy and small-angle X-ray scattering. Squalenoylation of gadolinium derivatives offers a platform to conceive contrast agents (CAs) in mild conditions (no toxic solvents, no surfactants, no energy input). These new amphiphilic gadolinium chelates could also find potential applications in theranostics, by forming mixed systems with other squalenoylated drugs, or to delineate blood vessels owing to the interaction with HSA. © 2011 The Royal Society of Chemistry.

Claude B.,CNRS Institute of Organic and Analytical Chemistry | Viron-Lamy C.,LVMH Recherche Parfums et Cosmetiques | Haupt K.,Compiègne University of Technology | Morin P.,CNRS Institute of Organic and Analytical Chemistry
Phytochemical Analysis | Year: 2010

Introduction - Plant extracts are usually complex mixtures of various polarity compounds and their study often includes a purification step, such as solid-phase extraction (SPE), to isolate interest compounds prior analytical investigations. Molecularly imprinted polymers (MIPs) are a new promising type of SPE material which offer tailor-made selectivity for the extraction of trace active components in complex matrices. Numerous specific cavities that are sterically and chemically complementary of the target molecules, are formed in imprinted polymers. A molecularly imprinted polymer (MIP) was synthesised in order to trap a specific class of triterpene, including betulin and betulinic acid from a methanolic extract of plane bark. Methodology - Imprinted polymers were synthesised by thermal polymerisation of betulin as template, methacrylic acid (MAA) or acrylamide (AA) as functional monomer, ethylene glycol dimethacrylate as crosslinking agent and chloroform as porogen. Afterwards, MAA- and AA-MIPs were compared with their non-imprinted polymers (NIPs) in order to assess the selectivity vs betulin and its derivatives. Recovered triterpenes were analysed by HPLC during MIP-SPE protocol. Results - After SPE optimisation, the MAA-imprinted polymer exhibited highest selectivity and recovery (better than 70%) for betulin and best affinity for its structural analogues. Thus, a selective washing step (chloroform, acetonitrile) removed unwanted matrix compounds (fatty acids) from the SPE cartridge. The elution solvent was methanol. Finally, the MAA-MIP was applied to fractionate a plane bark methanolic extract containing betulin and betulinic acid. Conclusion - This study demonstrated the possibility of direct extraction of betulin and its structural analogues from plant extracts by MIP technology. Copyright © 2009 John Wiley & Sons, Ltd.

Abdellaoui S.E.,CNRS Institute of Organic and Analytical Chemistry | Destandau E.,CNRS Institute of Organic and Analytical Chemistry | Krolikiewicz-Renimel I.,LVMH Recherche Parfums et Cosmetiques | Cancellieri P.,University of Orléans | And 5 more authors.
Separation and Purification Technology | Year: 2014

Clidemia hirta is an invasive shrub used in traditional medicine to treat some bacterial infections. In order to identify the molecules involved in this antimicrobial activity and to consider C. hirta as a potential source of preservative molecule usable in cosmetic applications, an antibacterial bio-guided screening of C. hirta root ethyl acetate extract was developed. Centrifugal partition chromatography performed using an Arizona N (heptane/ethyl acetate/methanol/water 1:1:1:1 v/v/v/v) system in descending mode, allowed to recover three fractions. For three samples of C. hirta root, independently collected, each crude extract and each fraction were tested against strains recommended in the current regulatory method for cosmetic preservative to evaluate the antimicrobial activity and on keratinocyte and fibroblast cells to verify the absence of skin cell toxicity. The first fraction showed an interesting antibacterial activity but also sometimes skin cell toxicity. Hydrolysable tannins, derivatives of ellagic acid were identified using mass spectrometry in this fraction. The second fraction was both antibacterial and not cytotoxic. Mass spectrometry and NMR experiments confirmed the isolation of only one compound in this fraction which was identified as arjunolic acid. © 2014 Elsevier B.V. All rights reserved.

Othman M.,University Paris - Sud | Bouchemal K.,University Paris - Sud | Couvreur P.,University Paris - Sud | Desmaele D.,University Paris - Sud | And 3 more authors.
Journal of Colloid and Interface Science | Year: 2011

Nanoassemblies (NAs) with sizes ranging from 60 to 160nm were spontaneously formed in water after mixing a host polymer (polymerized cyclodextrin (pβ-CD)) and a guest polymer (dextran grafted with lauroyl side chains (MD)). The combination of microscopy, dynamic light scattering (DLS), nuclear magnetic resonance (1H NMR), isothermal titration calorimetry (ITC) and molecular modelling was used to investigate the parameters which govern the association between MD and pβ-CD. Remarkably, when pβ-CD was progressively added to a solution of MD, NAs with a well-defined diameter were spontaneously formed and their diameter was constant whatever the composition of the system. According to NMR data, almost all the alkyl chains of MD were included into CDs' cavities of the polymer when the molar ratio lauroyl chain (C12)/CD was ≥1. The hydrophobic interaction between C12 and the hydrophobic cavities of CDs appears as the main driving force for NAs' formation, with a minor contribution arising from van der Waals' interactions. The inclusion of C12 into β-CD cavities is almost a completely enthalpy-driven process, whereas the MD-C12/pβ-CD interaction was found to be an entropy-driven process. Major conclusions which can be drawn from these studies are that the interactions between the two polymers are restricted neither by the MD substitution yield, nor by the micellization of MD. The simultaneous effects of several CD linked together in pβ-CD and of many alkyl chains grafted on dextran were necessary to generate these stable NAs. © 2010 Elsevier Inc.

PubMed | CNRS Mulhouse Institute of Materials Science, CNRS Laboratory of Molecular and Structural Archaeology, CNRS Laboratory of Condensed Matter Chemistry, Paris, ESPCI ParisTech and 2 more.
Type: | Journal: Angewandte Chemie (International ed. in English) | Year: 2017

British 19th century painters such as J.M.W. Turner, commonly modified the properties of their paint by using gels called gumtions. These gels allowed them to easily tune the paint handling and drying properties. The fascinating properties of these gumtions were obtained by adding lead acetate to a ternary system based on mastic resin, linseed oil and turpentine. Herein, we report and investigate in depth the rheological properties of these gels as well as their structure at a molecular and supra-molecular scale.

Boularas M.,University of Pau and Pays de l'Adour | Gombart E.,LVMH Recherche Parfums et Cosmetiques | Tranchant J.-F.,LVMH Recherche Parfums et Cosmetiques | Billon L.,University of Pau and Pays de l'Adour | Save M.,University of Pau and Pays de l'Adour
Macromolecular Rapid Communications | Year: 2015

This article reports a rational strategy for preparing smart oligo(ethylene glycol)-based hybrid microgels loaded with high content of homogeneously distributed preformed magnetic nanoparticles (NPs) (up to 33 wt%). The strategy is based on the synthesis of biocompatible multiresponsive microgels by precipitation copolymerization of di(ethylene glycol) methyl ether methacrylate, oligo(ethylene glycol) methyl ether methacrylate, methacrylic acid, and oligo(ethylene glycol)diacrylate. An aqueous dispersion of preformed magnetic NPs is straightforwardly loaded into the microgels. Robust monodisperse thermoresponsive magnetic microgels are produced, exhibiting a constant value of the volume phase transition temperature whatever the NPs content. The homogeneous microstructure of the initial stimuli-responsive biocompatible microgels plays a crucial role for the design of unique well-defined ethylene glycol-based thermoresponsive hybrid microgels. (Chemical Equation Presented). © 2014 Wiley-VCH Verlag GmbH & Co. KGaA.

Alves M.-H.,University of Pau and Pays de l'Adour | Sfeir H.,University of Pau and Pays de l'Adour | Tranchant J.-F.,LVMH Recherche Parfums et Cosmetiques | Gombart E.,LVMH Recherche Parfums et Cosmetiques | And 4 more authors.
Biomacromolecules | Year: 2014

The present work shows the synthesis of amphiphilic polymers based on the hydrophilic dextran and the hydrophobic terpenes as renewable resources. The first step concerns the synthesis of functional terpene molecules by thiol-ene addition chemistry involving amino or carboxylic acid thiols and dihydromyrcenol terpene. The terpene-modified polysaccharides were subsequently synthesized by coupling the functional terpenes with dextran. A reductive amination step produced terpene end-modified dextran with 94% of functionalization, while the esterification step produced three terpene-grafted dextrans with a number of terpene units per dextran of 1, 5, and 10. The amphiphilic renewable grafted polymers were tested as emulsifiers for the stabilization of liquid miniemulsion of terpene droplets dispersed in an aqueous phase. The average hydrodynamic diameter of the stable droplets was observed at about 330 nm. © 2013 American Chemical Society.

Boularas M.,University of Pau and Pays de l'Adour | Deniau-Lejeune E.,University of Pau and Pays de l'Adour | Alard V.,LVMH Recherche Parfums et Cosmetiques | Tranchant J.-F.,LVMH Recherche Parfums et Cosmetiques | And 2 more authors.
Polymer Chemistry | Year: 2016

Multi-responsive biocompatible microgels with long term stability were synthesized by precipitation copolymerization of oligo(ethylene glycol) methyl ether methacrylate (OEGMA), di(ethylene glycol) methyl ether methacrylate (MEO2MA), methacrylic acid (MAA) and crosslinkers in aqueous dispersed media. Different crosslinkers, i.e. ethylene glycol dimethacrylate (EGDMA), oligo(ethylene glycol) diacrylate (OEGDA) or N,N-methylenebisacrylamide (MBA) were used for the synthesis of the microgels. The present work investigates for the first time how the inner structure of the biocompatible P(MEO2MA-co-OEGMA-co-MAA) microgels impacts their swelling-to-collapse transition in response to both temperature and pH. The EGDMA-crosslinked microgels obviously differ from the OEGDA- and MBA-crosslinked microgels. The OEGDA-crosslinked P(MEO2MA-co-OEGMA-co-MAA) microgels are ideal candidates to prepare robust thermoresponsive hybrid magnetic microgels by a straightforward method involving simple loading of pre-formed magnetic nanoparticles (NP) in the absence of NP release. The crosslinker distribution is at the origin of differences in the distribution of iron oxide nanoparticles. The homogeneous distribution of both MAA units and the OEGDA crosslinker in the P(MEO2MA-co-OEGMA-co-MAA) microgels ensured a sharp VPTT of microgels over a wide range of pH values (from pH 4 to 9) and the retention of the thermoresponsiveness of the corresponding hybrid microgels for the different contents of magnetic nanoparticles (from 7 to 33 wt% of γ-Fe2O3versus polymer). Turbidimetry measurements highlighted the unique stability of the hybrid microgels over several hours even for the highest content of iron oxide nanoparticles. © The Royal Society of Chemistry 2016.

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