Elucidation of antioxidant activity and metabolite profiling of the marine soft coral Litophyton sp.

Soft corals are a rich source of metabolites with potential pharmaceutical applications. The study investigates the antioxidant activity and metabolite profile of Litophyton sp., collected from Sepanggar Island, North Borneo, Malaysia. Methanol extraction yielded 2.82% crude extract. Antioxidant activity was assessed using the DPPH and ABTS assays, with IC50 values of 42.63±2.98 and 24.53±2.55 mg/mL, respectively. The total phenolic content (TPC) and flavonoid content (TFC) were recorded at 0.017±0.007 GAE/g and 0.129±0.006 mg QE/g, respectively. Fourier-transform infrared spectroscopy (FTIR) analysis identified functional groups, including hydroxyl, methyl, alkyne, carbonyl, and alkane. LC-q-Orbitrap-MS identified 57 metabolites in positive mode, including fatty acids (17%) and aromatic compounds (9%), while purines (29%) dominated in negative mode, comprising 18 metabolites. Additionally, antioxidant metabolites such as citral, trigonelline, acetyl-L-carnitine, arachidonic acid, and docosahexaenoic acid were detected. The study expands the current knowledge about the antioxidant potential and metabolites of Litophyton sp. from North Borneo waters.