Comparison of extraction methods for chemical composition, antibacterial, depigmenting and antioxidant activities of Eryngium maritimum.

OBJECTIVE: The objective is to develop a natural cosmetic ingredient from Eryngium maritimum regarding the high interest of consumer in these ingredients for cosmetic use. METHODS: Five eco-friendly techniques of extraction were applied to Eryngium maritimum aerial parts among conventional reflux extraction (with green solvent) and alternative techniques (supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and ultrasound combined with microwave extraction (UAE + MAE)). Several criteria were evaluated to allow the optimal choice for an industrialized ingredient: yield of extraction, chemical composition and biological activities such as antimicrobial, antioxidant, anti-collagenase and anti-tyrosinase activities. The extracts were analysed by liquid chromatography mass spectrometry (LC-HRMS), and the hierarchical Pearson classification (HCA) allowed to highlight the group of metabolites preferably extracted depending on the technique of extraction used. RESULTS: The biological results highlight that SFE and 80% ethanol reflux extracts have the best responses to biological activities such as antimicrobial, depigmenting and antioxidant activities, followed by water reflux extraction. Their activities might be due to the presence of different groups of metabolites favourably extracted by these techniques. CONCLUSION: Among these extractions, water reflux extraction provided the optimal results considering the compromise between extraction yield and biological activities for the development of a cosmetic ingredient.

OBJECTIF: L'objectif est d'évaluer différentes méthodes d'extraction permettant l'obtention d'un ingrédient cosmétique naturel, à partir d'Eryngium maritimum, efficace biologiquement, et respectant les principes du développement durable et de la beauté éthique et responsable. MÉTHODES: Cinq techniques d'extraction respectueuses de l'environnement ont été appliquées à des parties aériennes d'Eryngium maritimum tels que le reflux conventionnel (avec des solvants agrosourcés) et des techniques alternatives (extraction au fluide supercritique (SFE), extraction assistée par micro-ondes (MAE), extraction assistée par ultrasons (UAE) et ultrasons combinés aux micro-ondes (UAE + MAE)). Plusieurs critères ont été évalués pour permettre le choix optimal d'un ingrédient cosmétique efficace, naturel et industrialisable : rendement d'extraction, composition chimique (sureté) et efficacités biologiques (antibactérien, antioxydant, anti-âge et dépigmentant). Les extraits ont été analysés par chromatographie liquide spectrométrie de masse (LC-HRMS), et la classification par hiérarchie de Pearson (HCA) a permis de mettre relier les groupes de métabolites extraits de préférence par technique d'extraction testée. RÉSULTATS: Les résultats biologiques mettent en évidence que les extractions par SFE et à reflux par éthanol 80% permettaient les meilleures réponses (les plus importantes) pour des activités antimicrobiennes, éclaircissantes et antioxydantes, devant l'extraction à reflux par l'eau. Leurs activités pourraient être dues à la présence préférentielle de certains groupes de métabolites extraits plus favorablement par ces techniques. CONCLUSION: Parmi les extractions testées, l'extraction par reflux à l'eau (procédé respectueux de l'environnement) d'Eryngium maritimum, fournit le meilleur compromis en termes d'efficacités biologiques plurielles, de rendement d'extraction et de productivité/consommation énergétique, pour le développement d'un ingrédient cosmétique 'ecofriendly'.

Systematic gene deletion and functional characterization of histidine kinase phosphorelay receptors (HKRs) in the human pathogenic fungus Aspergillus fumigatus.

Histidine kinase receptors (HKRs) appear to be a common strategy for model and pathogenic fungi to sense and respond to environmental stresses. In the human pathogen Aspergillus fumigatus, which is responsible for invasive aspergillosis, 13 genes potentially encoding HKRs have been identified. Until now, only three HKRs have been functionally characterized. The aim of this study was to perform the systematic invalidation of A. fumigatus HKR genes and the careful phenotypic characterization of the relevant mutants. This study notably allowed to gain new important insights into the role of HKRs in physiology of A. fumigatus. Actually, we showed that (i) NikA/TcsC could be involved in the cell wall integrity pathway, (ii) Fhk6 and PhkA were involved in the regulation of the "fluffy" developmental program, (iii) PhkB could participate in the regulation of conidiation and (iv) PhkA was implied in the resistance of oxidative stresses.

Acronycine derivatives: a promising series of anticancer agents.

The pyranoacridone acronycine (1) exhibits antitumor properties against a large panel of solid tumor models, but its moderate potency and low water solubility severely hampered the subsequent clinical trials. Development of synthetic analogues followed the isolation from several Sarcomelicope species of acronycine epoxide (17), which led to a hypothesis of bioactivation of acronycine by transformation of the 1,2-double bond into the corresponding oxirane. 1,2-Diacyloxy-1,2-dihydroacronycine derivatives exhibited antitumor properties, with a broadened spectrum of activity and an increased potency. The demonstration that acronycine interacted with DNA led to the development of benzo[a], [b], and [c]acronycine analogs. 1,2-Dihydroxy-1,2-dihydrobenzo[b]acronycine esters and diesters were active in human orthotopic models of cancers xenografted in nude mice. The activity of these compounds, exemplified by cis-1,2-diacetoxy-1,2-dihydrobenzo[b]acronycine (49), developed in phase I clinical trials under the code S23906-1, was correlated with their ability to give covalent adducts with DNA, involving reaction between the N-2 amino group of guanines in the minor groove and the ester group at the benzylic position of the drug. The influence of the kinetics of DNA alkylation on the cytotoxic and antitumor properties showed a strong correlation between antiproliferative activity and DNA alkylation kinetics, with the most cytotoxic compounds, appearing as the slowest DNA alkylators. Hybrid compounds associating the acridone or benzo[b]acridone chromophore of acronycine derivatives and the epoxyfuran alkylating unit present in psorospermin also displayed potent antiproliferative activities, alkylating DNA guanine units at position N-7 in the major groove, as natural xanthones belonging to the psorospermin series.