Isolation and Identification Endophytic Fungi from Red Betel Leaf (<i>Piper crocatum</i>) and Its Active Compound Activity as Antioxidant

Previous studies have indicated that red betel leaf and endophytic fungal extracts have the ability to treat various diseases. This study aimed to investigate the antioxidant compounds of endophytic fungi isolated from red betel leaves ( Piper crocatum ). Crude extracts from these fungi were analyzed for phytochemical content, cytotoxic activity, and antioxidant capacity. The ethyl acetate crude extract (EtOAc) from endophytes fermented in Potato Dextrose Broth (PDB) medium had the highest total phenolic content (TPC) and total flavonoid content (TFC) at 55.38±2.70 mg GAE/g and 14.54±1.02 mg QE/g, respectively, with an antioxidant DPPH activity of 84.68± 2.74 μmol TE/g. Comparatively, fresh leaves yielded TPC, TFC, and antioxidant activity values of 24.71±3.15 mg GAE/g, 4.39±0.88 mg QE/g, and 27.07±2.30 μmol TE/g, respectively. This demonstrated significant differences in TFC, TPC, and antioxidant assay DPPH activities between the endophytic fungal extracts and fresh leaves. The characterization results of endophytic fungi were Aspergillus sp., Penicillium sp., and Fusarium sp.. This study confirmed the potential toxicity activity of isolate 1, which produced high toxicity with LC50 value 24.83 ppm on brine shrimp larvae. Conclusively, isolate 1 ( Aspergillus sp.) was identified as a potential candidate for antioxidants and cytotoxic compounds for the early development of anticancer agents.