Efficient solvent extraction of antioxidant-rich extract from a tropical diatom, Chaetoceros calcitrans (Paulsen) Takano 1968

• Published in: Asian Pacific Journal of Tropical Biomedicine
• Main Authors: Su Chern Foo, Fatimah Md. Yusoff, Maznah Ismail, Mahiran Basri, Nicholas Mun Hoe Khong, Kim Wei Chan, Sook Kun Yau
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wolters Kluwer Medknow Publications 2015
• Subjects: Chaetoceros calcitrans; Microalgae; Diatoms; Antioxidants; Fucoxanthin; Phenolic acids; Efficient solvent extraction; Arctic medicine. Tropical medicine; RC955-962; Biology (General); QH301-705.5; Arctic
• Online Access: https://doi.org/10.1016/j.apjtb.2015.06.003; https://doaj.org/article/68e68f35981d44e8ac2ed7891f00aade

Objective: To compare the in vitro antioxidant capacity of a diatom, Chaetoceros calcitrans (C. calcitrans) extracted using six types of solvents. Methods: Each extract was evaluated in terms of extraction yield, total carotenoid, fucoxanthin content, total phenolic and antioxidant capacities (DPPH·− and ABTS·−+ scavenging activity and iron chelating activity). Results: The methanol extract exhibited the highest yield [(22.71 ± 0.96) g/100 g dry weight (DW)], total carotenoid [(4.46 ± 0.36) mg/g DW], total phenolic [(2.49 ± 0.08) mg gallic acid equivalents/g DW] and second highest fucoxanthin content [(2.08 ± 0.03) mg fucoxanthin/g DW] as compared to other solvent extracts. Methanolic extract also exhibited significantly higher (P < 0.05) scavenging (DPPH·−, ABTS·−+) and iron chelating activities. Conclusions: Methanol was the recommended solvent for the production of antioxidant rich extract from C. calcitrans. Both carotenoids and phenolic acids were found to be positively correlated to the antioxidant capacities of C. calcitrans. Lead bioactives confirmed by subsequent high performance liquid chromatography studies were fucoxanthin, gallic acid and protocatechuic acid.