A Biorefinery Approach to the Biomass of the Seaweed <i>Undaria pinnatifida</i> (Harvey Suringar, 1873): Obtaining Phlorotannins-Enriched Extracts for Wound Healing

• Main Authors: Carolina A. M. Ferreira, Rafael Félix, Carina Félix, Adriana P. Januário, Nuno Alves, Sara C. Novais, Juliana R. Dias, Marco F. L. Lemos
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Biomolecules
• Subjects: anti-inflammatory; antimicrobial; antioxidant; circular economy; phlorotannins
• Online Access: https://www.mdpi.com/2218-273X/11/3/461

Brown seaweeds are recognized sources of compounds with a wide range of properties and applications. Within these compounds, phlorotannins are known to possess several bioactivities (e.g., antioxidant, anti-inflammatory, and antimicrobial) with potential to improve wound healing. To obtain phlorotannins enriched extracts from <i>Undaria pinnatifida</i>, a biorefinery was set using low-cost industry-friendly methodologies, such as sequential solid–liquid extraction and liquid–liquid extraction. The obtained extracts were screened for their antioxidant and antimicrobial activity against five common wound pathogens and for their anti-inflammatory potential. The ethanolic wash fraction (wE100) had the highest antioxidant activity (114.61 ± 10.04 mmol·mg⁻¹ extract by Diphenyl-1-picrylhydrazyl (DPPH) and 6.56 ± 1.13 mM eq. Fe II·mg⁻¹ extract by and Ferric Reducing Antioxidant Power (FRAP)), acting efficiently against Gram-negative (<i>Pseudomonas aeruginosa</i>) and Gram-positive (<i>Staphylococcus aureus</i>) bacteria, and showing a nitric oxide production inhibition over 47% when used at 0.01 µg·mL⁻¹. NMR and FTIR chemical characterization suggested that phlorotannins are present. Obtained fraction wE100 proved to be a promising candidate for further inclusion as wound healing agents, while the remaining fractions analyzed are potential sources for other biotechnological applications, giving emphasis to a biorefinery and circular economy framework to add value to this seaweed and the industry.