Pharmaceutical and ecological valorization of co-products from forestry exploitation in New Caledonia

Dans un contexte général d’économie circulaire, la valorisation des bio-ressources forestière en Nouvelle-Calédonie (sciures, écorces et nœuds) est étudiée. Le Pinus caribaea Morelet est le bois le plus exploité sur l’archipel et sa composition moléculaire a été très peu étudiée. L’étude phytochimique des extraits a permis, dans un premier temps, d’évaluer la composition moléculaire. Puis, les extraits ont été biologiquement évalués pour leur capacité anti-radicalaire et antibiotique. Ensuite, les molécules analogues aux flavonoïdes identifiés dans les coproduits, ont étés synthétisées. puis évalués pour leurs capacités anti-inflammatoires, selon le modèle de macrophage murin RAW264.7 induit par le LPS pour la quantification de la production de NO. L’étude de la relation structure-activité (SAR) a permis d’identifier des biomolécules plateformes, pour de futures pharmacomodulations. Finalement, une étude de biosorption du nickel et d’autres éléments traces métalliques en solution, par la sciure du pin des caraïbes a été réalisée. Les paramètres optimaux de biosorption, désorption, sélectivité, et régénération ont été investigués et optimisés. Les modifications de surfaces par des traitements acides ou oxydants ont permis d’améliorer significativement les capacités de biosorption de cette ressource végétale.This study is based on the general context of circular economy, towards the valorization of forest bio-resources in New Caledonia, including co-products (sawdust, bark, knots). Pinus caribaea is the most exploited wood on the archipelago, and its molecular composition has been poorly described. First, the phytochemical study of extracts allows the evaluation of the molecular content. Then, extracts were evaluated for their anti-radical and antibiotic capacity. In a second step, derivatives were synthesized inspired by the structure of a major polyphenol found in this wood. These analogues were evaluated for their anti-inflammatory capacities, according to murine macrophages RAW264.7 treated with LPS (E. coli 0111:B4) for the inhibition of NO production. The structure-activity relationship (SAR) will allow platform biomolecules selection for the development of future anti-inflammatory drugs. Finally, the co-product of the caribbean pine was investigated for an ecological valorization. Sawdust and their macromolecules are evaluated for their ability to trap metals in solution, in particular nickel (II). The optimal parameters of biosorption, desorption, selectivity, and regeneration were investigated and optimized. Surface modifications through acid an oxidative treatments of co-products allowed a significant improvement of biosorption capacities of pine sawdust

Antioxidant activities and volatile compounds analysis of coproducts from conifers of logging industry in New Caledonia

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Synthesis and Investigation of Flavanone Derivatives as Potential New Anti-Inflammatory Agents

International audienceFlavonoids are polyphenols with broad known pharmacological properties. A series of 2,3-dihydroflavanone derivatives were thus synthesized and investigated for their anti-inflammatory activities. The target flavanones were prepared through cyclization of 2′-hydroxychalcone derivatives, the later obtained by Claisen–Schmidt condensation. Since nitric oxide (NO) represents an important inflammatory mediator, the effects of various flavanones on the NO production in the LPS-induced RAW 264.7 macrophage were assessed in vitro using the Griess test. The most active compounds were flavanone (4G), 2′-carboxy-5,7-dimethoxy-flavanone (4F), 4′-bromo-5,7-dimethoxy-flavanone (4D), and 2′-carboxyflavanone (4J), with IC50 values of 0.603, 0.906, 1.030, and 1.830 µg/mL, respectively. In comparison, pinocembrin achieved an IC50 value of 203.60 µg/mL. Thus, the derivatives synthesized in this work had a higher NO inhibition capacity compared to pinocembrin, demonstrating the importance of pharmacomodulation to improve the biological potential of natural molecules. SARs suggested that the use of a carboxyl-group in the meta-position of the B-ring increases biological activity, whereas compounds carrying halogen substituents in the para-position were less active. The addition of methoxy-groups in the meta-position of the A-ring somewhat decreased the activity. This study successfully identified new bioactive flavanones as promising candidates for the development of new anti-inflammatory agents

Anti-inflammatory effects of flavonoids derivatives: Investigation of their structure activity relationship

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Biosorption of nickel ions Ni2+ by natural and modified Pinus caribaea Morelet sawdust

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Perspectives de valorisation des co-produits de Pinus caribaea : composition phytochimique et activités anti-oxydantes et antimicrobiennes

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Valorization of pine biomass (Pinus caribaea Morelet) for the removal of nickel ions from aqueous solution.

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Perspectives de valorisation des co-produits de Pinus caribaea : composition phytochimique et activités anti-oxydantes et antimicrobiennes

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Polyphenol Content, Antioxidant, and Antibiotic Activities of Pinus Caribaea Morelet Forestry Coproducts

Context and objective In the context of valorization of wood waste from the timber industry, this work aims to study the chemical composition and to evaluate the biological capacities of coproducts from Pinus caribaea Morelet. Methods With this mind, sawdust, bark, and knot-wood from P caribaea were analyzed by high-performance liquid chromatography-mass spectrometry. The antioxidant activities of extracts and reference compounds were assessed in vitro using 2 methods: 2.2-diphenyl-1-picrylhydrazyl and 2.2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid). For antimicrobial evaluation, coproduct extracts were assayed against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Candida albicans. Results Despite the variable composition of sawdust, bark, and knot-wood, the composition of P caribaea is typical of the Pinus genus, with the presence of flavonoids, stilbenes, and lignans. Seven compounds were elucidated: 2 lignans (nortrachelogenin and matairesinol), 3 flavonoids (pinocembrin, pinobanksin, pinobanksin 3-acetate), 2 stilbenes (pinosylvin, pinosylvin monomethyl ether), and 1 phenolic acid (caffeic acid). Conclusion The ethanolic extracts of bark and knots showed significant antioxidant activity. The knots showed significant antibacterial properties against S epidermidis

SYNTHÈSE DE DÉRIVÉS CARBOXY-FLAVANONES ET ÉTUDE DE LEUR ACTIVITÉ ANTI-INFLAMMATOIRE : ÉTUDE DE LA RELATION STRUCTURE-ACTIVITÉ

International audienceFlavonoids are naturally occurring polyphenols with broad known pharmacological properties. Various synthetic 2,3-dihydroflavanone derivatives were synthesized to optimize their anti-inflammatory potential [1]. These compounds were prepared through cyclization of the corresponding 2’-hydroxychalcone derivatives, the later accessible by Claisen-Schmidt condensation. Nitric oxide (NO) is an important inflammatory mediator. Thus, the inhibitory activity of the flavanone derivatives on NO production in LPS-induced RAW264.7 macrophages were evaluated in vitro using the Griess test after cytotoxicity assessment. Among the most active compounds, 2-carboxy-5,7-dimethoxy-flavanone and 2-carboxyflavanone showed IC50 values of 0.906 and 1.830 g/mL, respectively, while the reference molecule, pinocembrin, achieved an IC50 value of 203.60 g/mL as expected [1]. Carboxy-flavanone thus has a greater capacity to inhibit NO production compared to the original molecule pinocembrin. The incorporation of a highly polar, acidic, and electron-accepting carboxyl-group was therefore investigated to potentially enhance the biological potential of flavanones. Following this approach, additional compounds bearing carboxy-groups on different positions of the B-ring were synthesized and subjected to a structure-activity relationship (SAR) study on their anti-inflammatory activities (Figure 1). This SAR-study subsequently identified novel bioactive flavanones as promising candidates for the development of new immunoregulatory agents. This study was funded by the Ministry of Foreign Affairs and International Development (MAEDI) and the Economic, Social and Cultural Cooperation Fund for the Pacific.[1] Sinyeue C., Matsui M., Oelgemöller M., Bregier F., Chaleix V., Sol V. & Lebouvier N., Molecules, 27, 1781, 2022. https://doi.org/10.3390/molecules2706178