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Sargassum muticum (SM) poses a serious environmental issue since it is a fast-expanding invasive species occupying key areas of the European shoreline, disrupting the autochthonous algae species, and disturbing the ecosystem. This problem has concerned the general population and the scientific community. Nevertheless, as macroalgae are recognized as a source of bioactive molecules, the abundance of SM presents an opportunity as a raw material. In this work, response surface methodology (RSM) was applied as a tool for the optimization of the extraction of bioactive compounds from SM by microwave-assisted extraction (MAE). Five different parameters were used as target functions: yield, total phenolic content (TPC); and the antioxidant measurements of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and β-carotene bleaching (BC). After the optimal extraction conditions were determined (time = 14.00 min; pressure = 11.03 bar; ethanol = 33.31%), the chemical composition and bioactivity of the optimum extract was evaluated to appraise its antioxidant capability to scavenge reactive species and as a potential antibacterial, antidiabetic, antiproliferation, and neuroprotective agent. The results lead to the conclusion that MAE crude extract has bioactive properties, being especially active as an antiproliferation agent and as a nitric oxide and superoxide radical scavenger.

Given the growing tendency of consumers to choose products with natural ingredients, food industries have directed scientific research in this direction. In this regard, algae are an attractive option for the research, since they can synthesize a group of secondary metabolites, called phenolic compounds, associated with really promising properties and bioactivities. The objective of this work was to classify the major phenolic compounds, compare the effectiveness of the different extractive techniques used for their extraction, from traditional systems (like heat assisted extraction) to the most advance ones (such as ultrasound, microwave or supercritical fluid extraction); the available methods for identification and quantification; the stability of the enriched extract in phenolic compounds and the main bioactivities described for these secondary metabolites, to offer an overview of the situation to consider if it is possible and/or convenient an orientation of phenolic compounds from algae towards an industrial application., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The Camellia genus comprises a vast array of underexplored medicinal plants that merit a systematic valorization to exploit their potential as natural sources of phytochemicals with associated health-promoting properties. In this work, flower extracts from eight poorly characterized Camellia japonica L. cultivars were subjected to polyphenol profiling through untargeted metabolomics combined with in vitro functional analysis. Anthocyanins, mostly represented by cyanidin 3- O -glycosides, flavones, and flavonols, were found as the major constituents of C. japonica flowers, together with hydroxycinnamic acids, tyrosols, alkylphenols, and stilbenes, which were detected for the first time in this species. The application of multivariate statistics revealed a flower color-dependent fingerprint of C. japonica cultivars, featuring anthocyanins and other flavonoids as metabolite markers associated with color-flowered cultivars with respect to white-flowered ones. The accumulation of anthocyanins, especially reported in 'Eugenia de Montijo' flowers, was highly correlated with the cytotoxic and anti-inflammatory properties of the derived extracts, including AGS, Caco-2, and MCF7 cancer cell lines. Moreover, the flavones accumulation reported in 'Carolyn Tuttle' extracts was also associated with high rates of free-radical scavenging activity, as well as a potent cytotoxicity against the Caco-2 cell line. In general, C. japonica anthocyanin-enriched flower extracts were revealed as promising candidates for the industrial production of polyphenols with associated biological activities of high interest for critical sectors in the food, pharmaceutical, and cosmetic industries. • Flower extracts of eight Camellia japonica cultivars were functionally valorized. • A combined untargeted metabolomics and in vitro bioactivity approach was performed. • Colored cultivars were revealed as promising sources of health-promoting agents. • Anthocyanin-enriched extracts exhibit cytotoxic and anti-inflammatory activities. [ABSTRACT FROM AUTHOR]