Analysis, classification and characterization of natural resins using liquid chromatography hyphenated to mass spectrometry

L’analyse et la classification de 31 résines végétales par différentes méthodes analytiques (HPTLC, CPL-UV, CPL-DEDL, CPL-SM, CPG-SM et RMN) a été réalisée dans un but d’établir un lien de parenté entre l’identité chimique d’une résine et son appartenance botanique. Les résines naturelles étant riches en dérivés triterpéniques une étude de leur détection par spectrométrie de masse (SM) a été menée montrant l’intérêt de l’ionisation douce pour cette famille moléculaire et l’avantage des sources APCI et APPI pour une détection sensible en LC-MS e ces composés. Ces métabolites secondaires peu polaires et très riches en isomères, ont nécessité la mise au point des méthodes d’extraction et de séparation efficace pour permettre l’amélioration de leur rendement d’extraction et faciliter leur identification dans leur milieu naturel. Trois dérivés triterpéniques ont été identifiés pour la première fois dans l’une des résines étudiées (Manilkara bidentata) et leur activité biologique a été testée sur des cellules de peau humaine en culture.The aim of this research was to analyze and classify 31 natural resins using different analytical tools (HPTLC, LC-UV, LC-ELSD, LC-MS, GC-MS and NMR) in order to verify the link between the chemical composition of resins and their botanic belongs. Natural resins are mostly composed from triterpens that is the reason why development of sensitive liquid chromatography method hyphenated to mass spectrometry detection was necessary. APPI and APCI were proved to be the most adequate sources of ionization for triterpens mass spectrometry analysis. Triterpens have low polarity index and contain number of isomers making their extraction and separation difficult in liquid chromatography. To improve their extraction and separation in their natural matrix, different parameters were considered. Finally, three triterpens derivatives were described for the first time in Manilkara bidentata resin and their bio-activity was tested on human skin cells cultures

Analyse, classification et caractérisation de résines d'origine végétale par chromatographie et spectrométrie de masse

L analyse et la classification de 31 résines végétales par différentes méthodes analytiques (HPTLC, CPL-UV, CPL-DEDL, CPL-SM, CPG-SM et RMN) a été réalisée dans un but d établir un lien de parenté entre l identité chimique d une résine et son appartenance botanique. Les résines naturelles étant riches en dérivés triterpéniques une étude de leur détection par spectrométrie de masse (SM) a été menée montrant l intérêt de l ionisation douce pour cette famille moléculaire et l avantage des sources APCI et APPI pour une détection sensible en LC-MS e ces composés. Ces métabolites secondaires peu polaires et très riches en isomères, ont nécessité la mise au point des méthodes d extraction et de séparation efficace pour permettre l amélioration de leur rendement d extraction et faciliter leur identification dans leur milieu naturel. Trois dérivés triterpéniques ont été identifiés pour la première fois dans l une des résines étudiées (Manilkara bidentata) et leur activité biologique a été testée sur des cellules de peau humaine en culture.The aim of this research was to analyze and classify 31 natural resins using different analytical tools (HPTLC, LC-UV, LC-ELSD, LC-MS, GC-MS and NMR) in order to verify the link between the chemical composition of resins and their botanic belongs. Natural resins are mostly composed from triterpens that is the reason why development of sensitive liquid chromatography method hyphenated to mass spectrometry detection was necessary. APPI and APCI were proved to be the most adequate sources of ionization for triterpens mass spectrometry analysis. Triterpens have low polarity index and contain number of isomers making their extraction and separation difficult in liquid chromatography. To improve their extraction and separation in their natural matrix, different parameters were considered. Finally, three triterpens derivatives were described for the first time in Manilkara bidentata resin and their bio-activity was tested on human skin cells cultures.ORLEANS-SCD-Bib. electronique (452349901) / SudocSudocFranceF

Sci Rep.

Overweight and obesity have been shown to significantly affect brain structures and size. Obesity has been associated with cerebral atrophy, alteration of brain functions, including cognitive impairement, and psychiatric diseases such as depression. Given the importance of lipids in the structure of the brain, here, by using 47 mice fed a high fat diet (HFD) with 60% calories from fat (40% saturated fatty acids) and 20% calories from carbohydrates and age-matched control animals on a normal chow diet, we examined the effects of HFD and diet-induced obesity on the brain lipidome. Using a targeted liquid chromatography mass spectrometry analysis and a non-targeted mass spectrometry MALDI imaging approach, we show that the relative concentration of most lipids, in particular brain phospholipids, is modified by diet-induced obesity (+ 40%of body weight). Use of a non-targeted MALDI-MS imaging approach further allowed define cerebral regions of interest (ROI) involved in eating behavior and changes in their lipid profile. Principal component analysis (PCA) of the obese/chow lipidome revealed persistence of some of the changes in the brain lipidome of obese animals even after their switch to chow feeding and associated weight loss. Altogether, these data reveal that HFD feeding rapidly modifies the murine brain lipidome. Some of these HFD-induced changes persist even after weight loss, implying that some brain sequelae caused by diet-induced obesity are irreversible.Bordeaux Region Aquitaine Initiative for NeuroscienceDissection des mécanismes hypothalamiques impliqués dans la détection du statut nutritionnel et régulation de la prise alimentaire via les interactions entre mTORC1, les mélanocortines et les endocannabinoïdes.La signalisation des acides biliaires dans le cerveau et son rôle dans le contrôle métaboliqueRôle du récepteur aux cannabinoïdes de type 1 mitochondriale dans les circuits hypothalamiques et son interaction avec la voie mTORC1 dans l'obésité.Innovations instrumentales et procédurales en psychopathologie expérimentale chez le rongeu

Pentacyclic triterpenes from Manilkara bidentata resin. Isolation, identification and biological properties

International audienceThree pentacyclic triterpenes were isolated for the first time from resinous plant Manilkara bidentata. Ultrasound-assisted extraction with ethanol was chosen after a comparison of various extraction methods. Analysis of the extract was performed by HPLC with evaporative light scattering detection and semi-preparative HPLC has enabled us to isolate two urs-12-enes (3 beta-O-acetyl-alpha-amyrin and 3 beta-O-trans cinnamyl-alpha-amyrin) and a lupane-type derivative (3 beta-O-trans cinnamyl lupeol). Structures were elucidated on the basis of HRESIMS, atmospheric pressure photoionization MS, and homo- and heteronuclear correlation NMR experiments. Antioxidant and anti-inflammatory activities were determined on Manilkara extract and isolated fractions. We have also investigated their action on collagen and fibronectin synthesis, two very important proteins of the extracellular matrix. Thus, Manilkara extract was able to decrease IL-1 beta and IL-8 pro-inflammatory cytokines. These activities exhibit the potential use of Manilkara extract as an anti-inflammatory and anti-aging ingredient for pharmaceutical and cosmetic industries

Comprehensive Targeted and Non-Targeted Lipidomics Analyses in Failing and Non-Failing Heart

Myocardial infarction (MI) and subsequent progressive heart failure pathology is the major cause of death worldwide; however, the mechanism of this pathology remains unclear. The present work aimed at testing the hypothesis whether the inflammatory response is superimposed with the formation of bioactive lipid resolving molecules at the site of the injured myocardium in acute heart failure pathology post-MI. In this view, we used a robust permanent coronary ligation model to induce MI, leading to decreased contractility index with marked wall thinning and necrosis of the infarcted left ventricle. Then, we applied mass spectrometry imaging (MSI) in positive and negative ionization modes to characterize the spatial distribution of left ventricle lipids in the infarcted myocardium post-MI. After micro-extraction, liquid chromatography coupled to tandem mass spectrometry was used to confirm the structures of the imaged lipids. Statistical tools such as principal component analysis were used to establish a comprehensive visualization of lipid profile changes in MI and no-MI hearts. Resolving bioactive molecules such as resolvin (Rv) D1, RvD5, RvE3, 17-HDHA, LXA4, and 18-HEPE were detected in negative ion mode MSI, whereas phosphatidyl cholines (PC) and oxidized derivatives thereof were detected in positive ion mode. MSI-based analysis demonstrated a significant increase in resolvin bioactive lipids with comprehensive lipid remodeling at the site of infarction. These results clearly indicate that infarcted myocardium is the primary location of inflammation-resolution pathomechanics which is critical for resolution of inflammation and heart failure pathophysiology

Photoacoustic imaging of tumor targeting with riboflavin-functionalized theranostic nanocarriers

Photoacoustic imaging is an emerging method in the molecular imaging field, providing high spatiotemporal resolution and sufficient imaging depths for many clinical applications. Therefore, the aim of this study was to use photoacoustic imaging as a tool to evaluate a riboflavin (RF)-based targeted nanoplatform. RF is internalized by the cells through a specific pathway, and its derivatives were recently shown as promising tumor-targeting vectors for the drug delivery systems. Here, the RF amphiphile synthesized from a PEGylated phospholipid was successfully inserted into a long-circulating liposome formulation labeled with the clinically approved photoacoustic contrast agent - indocyanine green (ICG). The obtained liposomes had a diameter of 124 nm (polydispersity index = 0.17) and had a negative zeta potential of -26 mV. Studies in biological phantoms indicated a stable and concentration-dependent photoacoustic signal (Vevo (R) LAZR) of the ICG-containing RF-functionalized liposomes. In A431 cells, a high uptake of RF-functionalized liposomes was found and could be blocked competitively. First, studies in mice revealed similar to 3 times higher photoacoustic signal in subcutaneous A431 tumor xenografts (P<0.05) after injection of RF-functionalized liposomes compared to control particles. In this context, the application of a spectral unmixing protocol confirmed the initial quantitative data and improved the localization of liposomes in the tumor. In conclusion, the synthesized RF amphiphile leads to efficient liposomal tumor targeting and can be favorably detected by photoacoustic imaging with a perspective of theranostic applications

Photoacoustic imaging of tumor targeting with riboflavin-functionalized theranostic nanocarriers

Photoacoustic imaging is an emerging method in the molecular imaging field, providing high spatiotemporal resolution and sufficient imaging depths for many clinical applications. Therefore, the aim of this study was to use photoacoustic imaging as a tool to evaluate a riboflavin (RF)-based targeted nanoplatform. RF is internalized by the cells through a specific pathway, and its derivatives were recently shown as promising tumor-targeting vectors for the drug delivery systems. Here, the RF amphiphile synthesized from a PEGylated phospholipid was successfully inserted into a long-circulating liposome formulation labeled with the clinically approved photoacoustic contrast agent - indocyanine green (ICG). The obtained liposomes had a diameter of 124 nm (polydispersity index = 0.17) and had a negative zeta potential of -26 mV. Studies in biological phantoms indicated a stable and concentration-dependent photoacoustic signal (Vevo (R) LAZR) of the ICG-containing RF-functionalized liposomes. In A431 cells, a high uptake of RF-functionalized liposomes was found and could be blocked competitively. First, studies in mice revealed similar to 3 times higher photoacoustic signal in subcutaneous A431 tumor xenografts (P<0.05) after injection of RF-functionalized liposomes compared to control particles. In this context, the application of a spectral unmixing protocol confirmed the initial quantitative data and improved the localization of liposomes in the tumor. In conclusion, the synthesized RF amphiphile leads to efficient liposomal tumor targeting and can be favorably detected by photoacoustic imaging with a perspective of theranostic applications