Exploiting the Integrated Valorization of Eucalyptus globulus Leaves: Chemical Composition and Biological Potential of the Lipophilic Fraction before and after Hydrodistillation.

E. globulus leaves have been mainly exploited for essential oil recovery or for energy generation in industrial pulp mills, neglecting the abundance of valuable families of extractives, namely, triterpenic acids, that might open new ways for the integrated valorization of this biomass. Therefore, this study highlights the lipophilic characterization of E. globulus leaves before and after hydrodistillation, aiming at the integrated valorization of both essential oils and triterpenic acids. The lipophilic composition of E. globulus leaves after hydrodistillation is reported for the first time. Extracts were obtained by dichloromethane Soxhlet extraction and analyzed by gas chromatography-mass spectrometry. In addition, their cytotoxicity on different cell lines representative of the innate immune system, skin, liver, and intestine were evaluated. Triterpenic acids, such as betulonic, oleanolic, betulinic and ursolic acids, were found to be the main components of these lipophilic extracts, ranging from 30.63-37.14 g kg-1 of dry weight (dw), and representing 87.7-89.0% w/w of the total content of the identified compounds. In particular, ursolic acid was the major constituent of all extracts, representing 46.8-50.7% w/w of the total content of the identified compounds. Other constituents, such as fatty acids, long-chain aliphatic alcohols and ß-sitosterol were also found in smaller amounts in the studied extracts. This study also demonstrates that the hydrodistillation process does not affect the recovery of compounds of greatest interest, namely, triterpenic acids. Therefore, the results establish that this biomass residue can be considered as a promising source of value-added bioactive compounds, opening new strategies for upgrading pulp industry residues within an integrated biorefinery context.

Characterization and Cytotoxicity Assessment of the Lipophilic Fractions of Different Morphological Parts of Acacia dealbata.

Acacia dealbata biomass, either from forest exploitation or from the management of invasive species, can be a strategic topic, namely as a source of high-value compounds. In this sense, the present study aimed at the detailed characterization of the lipophilic components of different morphological parts of A. dealbata and the evaluation of their cytotoxicity in cells representative of different mammals' tissues. The chemical composition of lipophilic extracts from A. dealbata bark, wood and leaves was evaluated using gas chromatography-mass spectrometry (GC-MS). Terpenic compounds (representing 50.2%-68.4% of the total bark and leaves extracts, respectively) and sterols (60.5% of the total wood extract) were the main components of these extracts. Other constituents, such as fatty acids, long-chain aliphatic alcohols, monoglycerides, and aromatic compounds were also detected in the studied extracts. All the extracts showed low or no cytotoxicity in the different cells tested, demonstrating their safety profile and highlighting their potential to be used in nutraceutical or pharmaceutical applications. This study is therefore an important contribution to the valorization of A. dealbata, demonstrating the potential of this species as a source of high value lipophilic compounds.

Lipophilic Fraction of Cultivated Bifurcaria bifurcata R. Ross: Detailed Composition and In Vitro Prospection of Current Challenging Bioactive Properties.

Macroalgae have been seen as an alternative source of molecules with promising bioactivities to use in the prevention and treatment of current lifestyle diseases. In this vein, the lipophilic fraction of short-term (three weeks) cultivated Bifurcaria bifurcata was characterized in detail by gas chromatography-mass spectrometry (GC-MS). B. bifurcata dichloromethane extract was composed mainly by diterpenes (1892.78 ± 133.97 mg kg-1 dry weight (DW)), followed by fatty acids, both saturated (550.35 ± 15.67 mg kg-1 DW) and unsaturated (397.06 ± 18.44 mg kg-1 DW). Considerable amounts of sterols, namely fucosterol (317.68 ± 26.11 mg kg-1 DW) were also found. In vitro tests demonstrated that the B. bifurcata lipophilic extract show antioxidant, anti-inflammatory and antibacterial activities (against both Gram-positive and Gram-negative bacteria), using low extract concentrations (in the order of µg mL-1). Enhancement of antibiotic activity of drug families of major clinical importance was observed by the use of B. bifurcata extract. This enhancement of antibiotic activity depends on the microbial strain and on the antibiotic. This work represents the first detailed phytochemical study of the lipophilic extract of B. bifurcata and is, therefore, an important contribution for the valorization of B. bifurcata macroalgae, with promising applications in functional foods, nutraceutical, cosmetic and biomedical fields.