Valorization of the Red Algae Gelidium sesquipedale by Extracting a Broad Spectrum of Minor Compounds Using Green Approaches

Area of Science:

• Marine Biotechnology
• Natural Product Chemistry
• Green Chemistry

Background:

• Red algae, specifically Gelidium sesquipedale, are primarily used for agar, leaving valuable minor compounds underexploited.
• Traditional extraction methods are time-consuming and less efficient for recovering diverse bioactive compounds.

Purpose of the Study:

• To investigate eco-friendly ultrasound-assisted extraction (UAE) and green solvents for valorizing minor compounds from Gelidium sesquipedale.
• To compare the efficiency and extraction time of green methods with conventional approaches.

Main Methods:

• Ultrasound-assisted extraction (UAE) using green solvents.
• Characterization of extracts for total phenolics, flavonoids, mycosporine-like amino acids (MAAs), and phycobiliproteins.
• Assessment of antioxidant and anti-enzymatic activities.

Main Results:

• UAE achieved efficient extraction of a broad spectrum of bioactive compounds in significantly shorter times (15-30 min) compared to conventional methods (8 h).
• Extracts were rich in total phenolics (189.3 mg GAE/100 g dw), flavonoids (310.7 mg QE/100 g dw), MAAs (Σ MAAs = 1271 mg/100 g dw), and phycobiliproteins (72.4 mg/100 g dw).
• The algal extracts demonstrated notable antioxidant and anti-enzymatic activities.

Conclusions:

• Eco-friendly UAE and green solvents offer an efficient and sustainable approach for the valorization of Gelidium sesquipedale biomass.
• The developed strategies can be adapted for the commercial utilization of various algae species and their bioactive compounds.
• This research opens new avenues for the cosmetic and medical industries by providing access to potent natural compounds.