Phenolic compounds, antioxidant and antibacterial activities of three Ericaceae from Algeria

International audienceHerbs of the Ericaceae family are commonly found in Algeria and used in traditional medicine as antiseptic, diuretic, astringent, depurative, and to treat scalds and wounds. The methanolic extracts of three species, Arbutus unedo L. (A. unedo, leaves), Erica arborea L. (E. arborea, flowered aerial parts), and Erica multiflora L. (E. multiflora, flowered aerial parts), were compared regarding their content in phenolic compounds, their antioxidant, and antibacterial activities. A. unedo harbors the highest content in total phenolics and flavonoids, followed by E. arboreaE. multiflora. The contents in total phenolics and flavonoids showed a correlation with the measured antioxidant (hydrogen-donating) activities; this was particularly the case for flavonoids content. The A. unedo extract showed antibacterial activity against all the tested strains (Staphylococcus aureus ATCC 6538, S. aureus C100459, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 9027); however, the E. arborea and E. multiflora extracts showed antibacterial activity only against Gram positive bacteria. Some polyphenols were identified in the three herbs by thin-layer chromatography and high-performance liquid chromatography coupled with diode array and mass spectrometry detection; from these, caffeic acid, p-coumaric acid, naringin, quercetin and kaempferol are reported for the first time in E. multiflora

Manufacturing and properties of biobased thermoplastic composites from poly(lactid acid) and hazelnut shell wastes

This is the peer reviewed version of the following article: Balart, J.F., Garcia-Sanoguera, David, Balart, Rafael, Boronat, Teodomiro, Sanchez-Nacher, Lourdes. (2018). Manufacturing and properties of biobased thermoplastic composites from poly(lactid acid) and hazelnut shell wastes.Polymer Composites, 39, 3, 848-857. DOI: 10.1002/pc.24007 , which has been published in final form at [Link to final article using the DOI]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Poly(lactic acid), PLA-based green composites were obtained with hazelnut shell flour (HSF) derived from the food industry thus leading to fully biodegradable materials with attracting properties. The hazelnut shell flour content varied in the 10-40wt% range. An increase in the degree of crystallinity with increasing HSF was detected, mainly due to the nucleating effect of lignocellulosic particles. The thermodimensional stability was noticeably improved with increasing HSF amount as evidenced by a remarkable decrease in the coefficient of thermal-linear expansion. Increasing HSF leads to stiffer materials as HSF particles act as interlock points that restrict polymer chain motion. Addition of hazelnut shell flour as filler in PLA-based green composites leads to fully biodegradable composites with balanced mechanical and thermal properties. Furthermore, it gives a solution to upgrade wastes from the hazelnut industry and contributes to lower the cost of PLA-based materials. POLYM. COMPOS., 39:848-857, 2018. (c) 2016 Society of Plastics EngineersContract grant sponsor: Ministerio de Economia y Competitividad-MINECO; contract grant number: MAT2014-59242-C2-1-R; contract grant sponsor: Conselleria d'Educacio, Cultura i Esport; contract grant number: GV/2014/008.Balart, J.; Garcia-Sanoguera, D.; Balart, R.; Boronat, T.; Sanchez-Nacher, L. (2018). Manufacturing and properties of biobased thermoplastic composites from poly(lactid acid) and hazelnut shell wastes. Polymer Composites. 39(3):848-857. doi:10.1002/pc.24007S84885739

Processing and characterization of high environmental efficiency composites based on PLA and hazelnut shell flour (HSF) with biobased plasticizers derived from epoxidized linseed oil (ELO)

[EN] Different amounts of epoxidized linseed oil (ELO) have been added to poly(lactic acid)-PLA composites with hazelnut shell flour (HSF) to provide a plasticizing effect and improve the low intrinsic ductile properties of PLA/HSF composites. Mechanical, thermal, thermo-mechanical and dynamic mechanical properties have been studied in terms of the weight percentage ELO. Mechanical resistant properties in both tensile and flexural tests decrease with wt.% ELO while a remarkable increase with wt.% ELO is obtained. These results reveal a clear plasticization effect of ELO but, in addition, internal structure of PLA/HSF/ELO composites shows good PLA-HSF (matrix-particle) interactions so that indicating that ELO also provides a coupling effect between PLA matrix and HSF filler. ELO addition leads to a decrease in storage modulus (G ) obtained by dynamic mechanical thermal analysis (DMTA) in torsion mode thus giving clear evidence of the plasticization effect of ELO. Overall, the use of ELO in PLA/HSF composites is an attracting way to improve the low intrinsic fragility of these green composites; furthermore, ELO provides an improvement on thermal stability and a coupling effect between the polymer matrix and the surrounding lignocellulosic filler.This research was supported by the Ministry of Economy and Competitiveness - MINECO, Grant Number: MAT2014-59242-C2-1-R. Authors also thank to "Conselleria d'Educacio, Cultura i Esport" - Generalitat Valenciana, Grant Number: GV/2014/008 for financial support.Balart Gimeno, JF.; Fombuena Borrás, V.; Fenollar Gimeno, OÁ.; Boronat Vitoria, T.; Sánchez Nacher, L. (2016). Processing and characterization of high environmental efficiency composites based on PLA and hazelnut shell flour (HSF) with biobased plasticizers derived from epoxidized linseed oil (ELO). Composites Part B: Engineering. 86:168-177. https://doi.org/10.1016/j.compositesb.2015.09.063S1681778

Evaluating the safety of herbal medicines: Integrated toxicological approaches.

peer reviewe

Studies on Cassytha filiformis from Benin: isolation, biological activities and quantification of aporphines

Cassytha filiformis (Lauraceae), a widely distributed pa rasitic plant, contains several aporphine alkaloids and is often used in African folk medicine to treat cancer, African trypanosomiasis and other diseases. Samples of C. filiformis from Benin were studied. We isolated and identified 6 aporphines and analysed the in vitrocytotoxic properties of four of them on different cancer and non-cancer cell lines. The major alkaloids (actinodaphnine, cassythine, and dicentrine) were also shown to possess antitrypanosomal properties in vitro on Trypanosoma brucei brucei. In order to elucidate their mechanism of action, the binding mode of these molecules to DNA was studied. The results of the optical measuremen ts showed that these three alkaloids bind to DNA and behave as typical intercalating agents. Biochemical experiments also indicated that they interfere with the cat alytic activity of topoisomerases. These interactions with DNA may explain, at least in part, the effects observed on cancer cells and on trypanosomes. In order to quantify these alkaloids in samples from different origins, a sensitive and accurate procedure based on an alkaloid extraction coupled to a HPLC-UV-MS determination has been developed for the separation and quantification of the major aporphines in C. filiformis. The extraction parameters and the liquid chromatography conditions were optimized in order to improve the selectivity of the method, which was completely validated using cassythine, one of the major aporphines in our samples, as reference standard. This procedure was successfully applied to the determination of these pharmacologically interesting aporphines in seven different batches of C. filiformis. The results showed variations in the total alkaloid content in samples, which ranged from 1.1 to 4.3

Study of active compounds from Cassytha filiformis L.

info:eu-repo/semantics/nonPublishe

Alimentation et chimioprévention

info:eu-repo/semantics/nonPublishe

Les défis de la médecine traditionnelle africaine: Le cas de la Guinée

info:eu-repo/semantics/nonPublishe