Development of new analytical tools for supercritical fluid extraction and chromatography : application to cosmetics

De nos jours, les consommateurs sont attentifs à l’impact environnemental que peut avoir les produits qu’ils consomment. Tous les domaines de l’industrie s’adaptent donc afin de répondre à ces attentes et le domaine de la cosmétique n’est pas exempt. Cette thèse a donc pour objectif de démontrer que les fluides supercritiques peuvent être utilisés dans le développement d’ingrédients cosmétiques à différentes étapes de ce dernier. En effet, l’utilisation de CO2 supercritique est en parfait accord avec les préceptes de la chimie verte et plus particulièrement ceux en lien avec l’éco-extraction. Une partie des travaux de cette thèse sera ainsi consacrée au développement de méthodes analytiques « vertes ». Le premier chapitre est dédié à l’utilisation de la chromatographie en phase supercritique (SFC) et son couplage à la spectrométrie de masse haute résolution (HRMS). L’objectif est de caractériser des absolues de fleurs, et plus particulièrement les absolues de Jasmin, matière première très utilisée en parfumerie/cosmétique, par SFC-RMS. La méthode développée s’est montrée complémentaire avec les techniques classiques de chromatographie en phase gazeuse couplée à la MS (GC-MS). Le deuxième chapitre aborde la SFC couplée à un détecteur ultraviolet permettant l’analyse des terpènes, composés majoritaires des huiles essentielles de Citrus. L’aspect quantitatif est abordé également pour le dosage du limonène, un composé allergène. Les résultats obtenus sont comparables à ceux obtenus en GC couplé à un détecteur à ionisation de flamme (GC-FID). Le troisième chapitre est consacré à l’utilisation de l’ionisation électronique (EI) comme source d’ionisation. Une étude préliminaire a validé l’utilisation de données générées en GC-EI-MS afin de construire des réseaux moléculaires. Le développement d’un couplage SFC-EI-MS est ensuite décrit afin de générer des données pouvant ensuite être retraitées à l’aide des réseaux moléculaires. Le quatrième chapitre traite du développement du couplage en ligne de l’extraction en phase supercritique SFE et de la SFC afin de suivre des cinétiques d’extraction de composés cibles mais également de limiter la préparation d’échantillon pour analyser les extraits SFE obtenus. Enfin le dernier chapitre s’intéresse à l’aspect phytochimie à travers l’extraction bioguidée d’aiguilles de sapin de Sibérie (Abies sibirica).Nowadays, consumers are aware of the environmental impact of the products they consume. All fields of industry are adapting to meet these expectations and the field of cosmetics is not exempt. This thesis aims to demonstrate that supercritical fluids can be used in the development of cosmetic ingredients at different stages of the latter. Indeed, the use of supercritical CO2 is in perfect agreement with the precepts of green chemistry and more particularly those related to eco-extraction. Part of the work of this thesis will be devoted to the development of "green" analytical methods. The first chapter is dedicated to the use of supercritical phase chromatography (SFC) and its coupling to high resolution mass spectrometry (HRMS). The objective is to characterize flower absolutes, and more particularly Jasmine absolutes, a raw material widely used in perfumery/cosmetics, by SFC-RMS. The developed method was shown to be complementary with the classical techniques of gas chromatography coupled to MS (GC-MS). The second chapter deals with the SFC coupled with an ultraviolet detector allowing the analysis of terpenes, the main compounds of Citrus essential oils. The quantitative aspect is also discussed for the determination of limonene, an allergenic compound. The results obtained are comparable to those obtained with GC coupled to a flame ionization detector (GC-FID). The third chapter is devoted to the use of electron ionization (EI) as an ionization source. A preliminary study validated the use of data generated in GC-EI-MS in order to build molecular networks. The development of a SFC-EI-MS coupling is then described in order to generate data that can then be reprocessed using the molecular networks. The fourth chapter deals with the development of an on-line coupling of supercritical phase extraction SFE and SFC in order to follow the extraction kinetics of target compounds but also to limit the sample preparation for the analysis of the SFE extracts obtained. Finally the last chapter focuses on the phytochemistry aspect through the bioguided extraction of Siberian fir (Abies sibirica) needles

Generation of a Molecular Network from Electron Ionization Mass Spectrometry Data by Combining MZmine2 and MetGem Software

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Comparison of Supercritical Fluid Chromatography Hyphenated to an Ultraviolet Detector and Gas Chromatography Hyphenated to a Flame Ionization Detector for Qualitative and Quantitative Analysis of <i>Citrus</i> Essential Oils

A comparison between the classical gas chromatography (GC) technique with supercritical fluid chromatography (SFC) technology was performed using an essential oil of Citrus limon (lemon) as a model, considering its wide use in the cosmetic world. For the qualitative part, the signal annotation was achieved by mass spectrometry using either an electron ionization (EI) or an atmospheric pressure photoionization (APPI) source. For the quantitative part, GC was hyphenated to a flame ionization detector (GC-FID) and SFC to an ultraviolet detector (SFC-UV). The assay of the major component of citrus oil, i.e., limonene, was carried out by SFC-UV. The similar results obtained between GC-FID and SFC-UV allows SFC-UV to be considered as an alternative to GC-FID for Citrus oil characterization. Then, analyses of an essential oil collection from Citrus fruits were achieved to confirm the potential use of SFC-UV for oil classification in the context of quality control of raw materials in cosmetics

Impact of the Post-Harvest Period on the Chemical and Sensorial Properties of <i>planifolia</i> and <i>pompona</i> Vanillas

Vanilla production in Guadeloupe is expanding. The main species grown is Vanilla planifolia, but other species such as Vanilla pompona are also present and required by industries. To upgrade the value of vanilla production on this Caribbean Island, this study was performed to evaluate the aromatic specifies of these vanilla species according to the length of the post-harvest period (2 months and 9 months). For this purpose, Vanilla planifolia and Vanilla pompona were compared through scald and scarification transformation processes, as well as two different refining times (T1 and T2). For chemical characterization, 0.1 g of vanilla bean seeds was used for SMPE/GC-MS measurements, while 0.05 g of vanilla samples was subjected to infusion in milk (0.15%) for sensory evaluation. The latter involved generation of terms of aroma through olfaction and gustation sessions. The chemical results showed a significant difference between the two species, where vanillin was mostly present in Vanilla planifolia, unlike Vanilla pompona, where it was mainly rich in 4-methoxybenzyl alcohol. Interestingly, the second refining time was characterized by the appearance of two major components, 1,3-octadien and acetic acid. For sensory analysis, all the vanillas exhibited a high diversity of aromas including “sweet”, ”gourmand”, “spicy” flavors and so on. The application of factorial correspondence analysis (FAC) as well as the agglomerative hierarchical clustering (AHC) showed differences between the vanilla samples according to both the species and refining time. The combination of these analyses makes it possible to establish a chemical and organoleptic profile of vanillas. Varietal and processing factors both have a major impact on the aroma profile of vanillas

Oxygen Exposure and Tolerance Shapes the Cell Wall-Associated Lipids of the Skin Commensal <i>Cutibacterium acnes</i>

Cutibacterium acnes is one of the most abundant bacteria on the skin. Being exposed to oxygen and oxic stress, the secretion of the bacterial antioxidant protein RoxP ensures an endogenous antioxidant system for the preservation of skin health. To investigate the impact of the antioxidant RoxP on oxidation of the bacteria, wildtype and an isogenic roxp mutant were cultured in anaerobic and oxic conditions. The carbonylated status of proteins were recorded, as were the most significant modifications in a relative intensity of free fatty acids (FFA) and lipids containing fatty acids (FA), such as di- (DG) and triglycerides (TG), di- (DGDG) and sulfoquinozyldiacylglycerol (SQDG) and ceramides. Concerning the fatty acid types, it was observed that the free fatty acids contained mainly C12:0–C26:0 in hydroxy and acylated forms, the DG contained mainly C29:0–C37:0, the TG contained mainly C19:0–C33:0, and the DGDG/SQDGs contained very long fatty acids (C29:0–C37:0) demonstrating the interdependence of de novo synthesis of lipids and RoxP. The area of DGDG peaks (924.52, 929.56 and 930.58) were affected by bacterial growth conditions, with the exception of m/z 910.61. Moreover, the FFA unsaturation is wider in the SQDG species (C30:0 to C36:6) than in DG, TG or free FFA species. It could be concluded that both environmental oxidative statuses, as well as the prevalence of bacterial antioxidant systems, significantly shape the lipidome of C. acnes

Composition of antifungal volatile organic compounds in Sextonia rubra fruit by molecular networks

Sextonia rubra is a tropical tree exploited for its durable wood. Hydrodistillation of its fruit was performed for the first time and the resulting hydrolate was analyzed by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) together with the dried fruit. Data analysis was performed by conventional methods and by molecular networks using MetGem software. Our methodology proved to be efficient to annotate the compounds detected complementary to the use of MassHunter Unknown Analysis. Hydrolate and dried fruit both displayed a rich and diverse HS-SPME-GC-MS sesquiterpenic profile, alongside with moderate antimicrobial activity towards the filamentous fungus Tricophyton rubrum for the hydrolate.Sextonia rubra est un arbre tropical exploité pour son bois durable. Pour la première fois, une hydrodistillation de ses fruits a été réalisé. L’hydrolat résultant et les fruits séchés ont été analysés en espace de tête-microextraction en phase solide-chromatographie en phase gazeuse-spectrométrie de masse (ET-MEPS-CG-SM). Le traitement des données a été réalisé par des méthodes conventionnelles et à laide de réseaux moléculaires en utilisant le logiciel MetGem. Notre méthodologie sest avérée pertinente pour annoter les composés détectés et ce, de manière complémentaire à l’utilisation de MassHunter Unknown Analysis. L’hydrolat et les fruits séchés possèdent tous deux des profils riches et divers majoritairement représenté par des sesquiterpènes. L’hydrolat possède une activité antimicrobienne modérée contre le champignon filamenteux Tricophyton rubrum

Sex differences in mandibular repositioning device therapy effectiveness in patients with obstructive sleep apnea syndrome

International audiencePurpose: Mandibular repositioning devices (MRDs) are an effective treatment option for obstructive sleep apnea syndrome (OSAS), particularly in patients who refuse or cannot tolerate continuous positive airway pressure (CPAP). However, sex differences in the response to therapy and predictors of response are not clearly defined. This analysis of data from the long-term prospective ORCADES trial compared MRD efficacy in men and women with OSAS.Methods: The ORCADES study included patients with newly diagnosed mild-to-moderate or severe OSAS who refused or were non-compliant with CPAP. MRD therapy was titrated over 3-6 months. The primary endpoint was treatment success (≥ 50% decrease in apnea-hypopnea index (AHI)). Complete response was defined using a range of AHI cut-off values ( 30/h) were 100% and 68% (p = 0.0015). In women vs. men, overall complete response rates at AHI cut-off values of < 5/h, <10/h, and < 15/h were 49 vs. 34% (p = 0.0052), 78 vs. 62% (p = 0.016), and 92 vs. 76% (p = 0.0032). On multivariate analysis, significant predictors of MRD treatment success were overbite and baseline apnea index in men, and neck circumference and no previous CPAP therapy in women. There were sex differences in the occurrence of side effects. Temporomandibular joint pain was the most common reason for stopping MRD therapy.Conclusions: MRD therapy was effective in women with OSA of any severity, with significantly higher response rates compared with men especially in severe OSAS