DOI: https://doi.org/10.55373/mjchem.v24i4.135

Keywords: Antioxidant, phytochemical, Padina minor, Sargassum polycystum

Abstract

Seaweed and its derivatives are rich in bioactive components, which have been widely utilized as biostimulants in crop production to increase plant growth and productivity. The current study was conducted to evaluate the phytochemical contents and antioxidant capacity of aqueous seaweed extracts as a potential biostimulant for plant growth. The brown seaweeds studied were Sargassum polycystum and Padina minor, which were collected from Semporna and Kota Kinabalu, Sabah, respectively. The phytochemical contents namely, total flavonoid content (TFC), total phenolic content (TPC) and total anthocyanin content (TAC); and antioxidant activity (FRAP, DPPH, and ABTS radicals scavenging) of aqueous seaweed extracts were analysed using standard procedures. The results showed that S. polycystum has relatively higher TPC and TFC compared to P. minor. Meanwhile, the TAC of both seaweeds are not significantly different from one another. The antioxidant activities based on DPPH radical scavenging activity (IC50), ABTS radical scavenging activity (IC50) and ferric reducing power assays of S. polycystum were significantly higher than P. minor