Extraction Of Bioactive Compounds From Seaweed Dictyota Dichotoma (Hudson) J.V. Lamouroux And Assessment Of Its Antioxidant Activity

Abstract

The seaweed Dictyota dichotoma is an untapped marine resource and majority of the compounds from this seaweed is still unexplored. The present study was designed to explore the antioxidant effects of D. dichotoma. The preliminary screening of phytocompounds from different solvent extracts was quantitatively analysed. The results showed that ethyl acetate extracts of D. dichotoma contain more amounts of phenols (24.1 ± 0.5 mg GAE/g extract), tannin (12.14 ± 0.2 mg GAE/g extract) and flavonoids (26.0 ± 5.8 mg RE/g extract). The antioxidant activity of D. dichotoma solvent extract was studied by DPPH and H₂O₂ scavenging assay. Among the extracts tested, the ethyl acetate extract has shown the highest DPPH radical scavenging (IC₅₀ - 458.24 ± 2.98 µg/mL), and H₂O₂ (IC₅₀ - 20.57 ± 13.82 µg/mL) activity. The presence of various bioactive compounds in the extract was confirmed by FTIR-ATR and GC-MS analysis. The FTIR-ATR spectra analysis exhibited alkane, carboxylic acid and aromatic amine in the extracts. The ethyl acetate extracts of GC-MS analysis showed major phytocompounds of n-Hexadecenoic acid, tri, tetra, penta, and octadecanoic acid. Hence, this study could be used to fractionate the promising bioactive compounds from the extracts and lead to the developing of novel drugs with potential biomedical applications.