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Common spruce ( Picea abies L.) is a fast-growing coniferous tree, widely used in several countries for the production of sawn wood, timber and pulp. During this industrial exploitation, large quantities of barks are generated as waste materials. The aim of this study was the bio-guided investigation and the effective recovery of methanol-soluble metabolites of common spruce bark for the development of new dermo-cosmetic agents. The active methanol extract was initially fractionated by Centrifugal Partition Chromatography (CPC) using a triphasic solvent system in a step-gradient elution mode. All resulting fractions were evaluated for their antibacterial activity, antioxidant activity and their capability to inhibit tyrosinase, elastase and collagenase activity. In parallel, the chemical composition of each fraction was established by combining a 13 C-NMR dereplication approach and 2D-NMR analyses. As a result, fourteen secondary metabolites corresponding to stilbene, flavonoid and phenolic acid derivatives were directly identified in the CPC fractions. A high amount (0.93 g) of E -astringin was recovered from 3 g of crude extract in a single 125 min run. E -Astringin significantly induced the tyrosinase activity while E -piceid, taxifolin, and taxifolin-3'- O -glucopyranoside exhibited significant anti-tyrosinase activity. The above compounds showed important anti-collagenase and antimicrobial activities, thus providing new perspectives for potential applications as cosmetic ingredients.

Wood residues produced from forestry activities represent an interesting source of biologically active, high value-added secondary metabolites. In this study, 30 extracts from 10 barks of deciduous and coniferous tree species were investigated for their potential dermo-cosmetic use. The extracts were obtained from Fagus sylvatica, Quercus robur, Alnus glutinosa, Prunus avium, Acer pseudoplatanus, Fraxinus excelsior, Populus robusta, Larix decidua, Picea abies , and Populus tremula after three successive solid/liquid extractions of the barks with n- heptane, methanol, and methanol/water. All extracts were evaluated for their radical scavenging capacity, for their elastase, collagenase, and tyrosinase inhibitory activities, as well as for their antibacterial activity against gram-positive Staphylococcus aureus . In parallel, the global metabolite profiles of all extracts were established by 1D and 2D NMR and related to their biological activity. The results showed that the methanol extracts of Q. robur, A. glutinosa, L. decidua , and P. abies barks exhibit particularly high activities on most bioassays, suggesting their promising use as active ingredients in the dermo-cosmetic industry., (Georg Thieme Verlag KG Stuttgart · New York.)

Barks from conifers and broadleaved trees constitute abundant wastes generated from wood harvesting and logging activities. Extracts of such residues obtained from Alnus trees have been reported as interesting resources with potent antibacterial activities. The present study aims to determine the antimicrobial activity of a crude methanol extract prepared from the bark of Alnus glutinosa against a panel of 22 bacteria and yeasts and to optimize a purification method enabling the high production of the most active substances. Fractionation of the crude extract was performed by Centrifugal Partition Chromatography (CPC) using a three-phase solvent system composed of n-heptane, methyl-ter-butyl ether, acetonitrile and water. The major known compounds contained in the fractions produced by CPC were chemically profiled by (13)C NMR dereplication, resulting in the unambiguous identification of oregonin, hirsutanonol, betulinic acid, and alusenone 1a. The antibacterial evaluation of the fractions by bioautography on Staphylococcus aureus revealed that oregonin, in addition to being the major metabolite of the crude extract (∼32% w/w), was the most active with an antibacterial inhibitory effect comparable to antibiotics. The purification of oregonin was optimized at the laboratory-scale by CPC. A single injection of 3.7g of crude extract resulted in a recovery of 72% (850mg) of the available oregonin at purity higher than 94%., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Introduction: Tree bark represents an interesting source of bioactive molecules for the discovery of new pharmaceutical agents. However, the detailed screening of secondary metabolites in crude bark extracts is often hampered by the presence of tannins, which are difficult to separate from other plant constituents., Objective: In the present study, a new centrifugal partition extraction (CPE) method was developed in order to fractionate a crude bark extract of Anogeissus leiocarpus Guill. & Perr. (Combretaceae)., Methods: A three-phase solvent system composed of n-heptane, methyl tert-butyl ether, acetonitrile and water was optimised for the stepwise elution at 20 mL/min of different phytochemical classes according to their hydrophobicity. Onedimensional and two-dimensional NMR analyses of the simplified fractions were then performed in order to characterise potentially interesting metabolites., Results: In one step, 5 g of the initial crude extract were efficiently fractionated to yield highly simplified fractions that contained triterpenes, ellagic acid derivatives, flavonoids and phenolic compounds. All undesired compounds, that is, the highly abundant water-soluble tannins (78.8%), were totally removed and each run was rapidly achieved in 90 min on a the multi-gram scale and with low solvent volumes., Conclusion: Centrifugal partition extraction in the elution mode using a three-phase solvent system can thus be proposed as an efficient and cost-effective alternative for a rapid fractionation of crude bark extracts and for an effective screening of potentially active secondary metabolites., (Copyright © 2013 John Wiley & Sons, Ltd.)