Synthesis of water-compatible imprinted polymers of in situ produced fructosazine and 2,5-deoxyfructosazine

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Optimization and kinetic modelling of robinetin and dihydrorobinetin extraction from Robinia pseudoacacia wood

International audienceDue to its rapid growth and important biomass production abilities, black locust (Robinia pseudoacacia L.) wood could represent an interesting source of natural compounds. Here, we optimized the extraction of the two main flavonoids accumulated in this species wood (i.e.: robinetin and dihydrorobinetin) with 80:20 (w:w) ethanol:water solvent well adapted for further industrial uses such as cosmetics. Our experimental design focused on two main extraction parameters: temperature and wood/solvent volume ratio that were optimized to 27.5 °C and 177 g L−1, respectively. These conditions lead to an optimal recovery of about 3000 mg L−1 of dihydrorobinetin and 700 mg L−1 of robinetin in the extracts. Interestingly, the effect of temperature could be neglected allowing reduced energy consumptions at the industrial level. Analysis of the evolution of robinetin and dihydrorobinetin concentrations during the timespan of the experiments revealed similar behaviours for both molecules. Kinetic modelling of robinetin and dihydrorobinetin release showed that pseudo-second order rate laws described well the extraction process with r2 values over 0.91. In the end, the results of this study provided useful insights to scale-up the extractions and lead to an industrial production of black locust wood extracts enriched in both flavonoids of interest

New strategy for the protection of consumers: a functionnal film limiting exposure to fragrance allergens

International audienc

New strategy for the protection of consumers: A functional film limiting exposure to fragrance allergens

International audienc

Gram-Scale Purification of Dihydrorobinetin from Robinia pseudoacacia L. Wood by Centrifugal Partition Chromatography

Article en Open AccessInternational audienceRobinia pseudoacacia L. is a tree widely dispersed in France that is characterized by good growth rates and important biomass production, which produces wood with very high natural durability used for outdoor fence posts, timber, and barrels to age vinegars and wines. Its mature heartwood presents high resistance against wood fungi decay and contains two main flavonoid extractives, dihydrorobinetin—the most abundant—and robinetin that present interesting biological activities. The aim of the present study was to optimize a procedure allowing an important recovery of purified dihydrorobinetin from R. pseudoacacia wood, representing an interesting sustainable, local, highly available, and, consequently, economical source of bioactive components. The extraction of dihydrorobinetin was first optimized by evaluating the influence of various extraction parameters such as temperature, extraction time, solvent nature, and wood/solvent mass ratio to obtain an efficient, safe, and low cost extraction. Then, dihydrorobinetin was purified over 95% using centrifugal partition chromatography (CPC). CPC purification was first developed on a small volume column with low amounts of injected extract, then scaled-up on a 200 mL column with higher sample loading capacity in order to purify more than 1.3 g of dihydrorobinetin in one run

Local wood (biomolecules) valorisation through the characterization and industrial production of Robinetin, a yellowish fluorescent colorant

National audienc

Nettle (Urtica dioica L.) as a source of antioxidant and anti-aging phytochemicals for cosmetic applications

Nettle (Urtica dioica L.) is a herbaceous perennial that has been used for centuries in folk medicine. More recently, nettle extracts have also been used in cosmetics because of the many benefits of their topical application for skin health. Their potential anti-aging action is of particular interest and is primarily ascribed to their antioxidant capacity. Here, using an experimental design approach and a clustering analysis, we linked the phytochemical composition of nettle extracts to their biological activities. This approach confirmed the antioxidant capacity of nettle extracts as well as providing the first evidence of another mechanism for their anti-aging potential involving the inhibition of enzyme activities, such as elastase and collagenase. We attributed these inhibitory effects to ursolic acid and quercetin present in the nettle extracts. Our results also demonstrated the possibility of extracting ursolic acid, quercetin and other phenolic compounds differentially to obtain an extract with a strong antioxidant capacity and anti-aging activities toward both elastase and collagenase. This could be of particular interest for cosmetic applications of nettle extracts.L'ortie (Urtica dioica L.) est une plante herbacée vivace utilisée depuis des siècles en médecine traditionnelle. Plus récemment, les extraits d'ortie ont été également utilisés dans des produits cosmétiques en raison des nombreux effets bénéfiques de leurs applications topiques sur la santé de la peau. En particulier, leur potentielle action anti-âge présente un fort intérêt et a été essentiellement attribuée à leur fort pouvoir antioxydant. Dans cette étude, en utilisant un plan d'expérience et une analyse hiérarchisée, nous avons connecté la composition phytochimique d'extraits d'ortie à leurs activités biologiques. Cette approche nous a permis de confirmer la capacité antioxydante des extraits d'ortie, mais aussi de proposer la première preuve d'un autre mécanisme de leur potentiel anti-âge impliquant l'inhibition d'activités enzymatiques. En effet, nos travaux montrent que ce second mécanisme implique l'inhibition d'enzymes de dégradation de la matrice extracellulaire telles que l'élastase et de la collagénase, et ces effets inhibiteurs ont été attribuables principalement à l'acide ursolique et la quercétine présents dans les extraits d'ortie. Nos résultats ont également mis en évidence la possibilité d'extraire de manière différentielle l'acide ursolique, la quercétine et d'autres composés phénoliques pour obtenir un extrait avec une forte capacité antioxydante et une activité anti-âge au travers de l'inhibition à la fois de l'élastase et de la collagénase, ce qui pourrait être d'un intérêt particulier pour les applications cosmétiques des extraits d'ortie

Effect of zein additive on perfume evaporation

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