Molecular Identification and Antioxidant Profiling of Penicillium heteringtonii EUA-017 from Mangrove (Avicennia alba) in West Sumatra, Indonesia

Mangrove ecosystems harbor diverse endophytic fungi that produce bioactive secondary metabolites with potential antioxidant activities. This study aimed to identify an endophytic fungal isolate (EUA-017) from Avicennia alba mangroves in West Sumatra, Indonesia, and characterize its antioxidant metabolites. Molecular identification was performed using internal transcribed spacer (ITS) region sequencing. Secondary metabolites from ethyl acetate extracts were characterized using Fourier-transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Phylogenetic analysis identified isolate EUA-017 as Penicillium hetheringtonii, showing high sequence similarity (≥98%) to P. hetheringtonii CBS 122392. FTIR analysis revealed 16 distinct absorption peaks representing various functional groups. GC-MS analysis identified 12 compounds, of which 10 exhibited predicted antioxidant activity based on structural analysis. LC-MS/MS detected 12 compounds, with 5 demonstrating potential antioxidant properties. The compound exhibiting the highest predicted antioxidant activity from GC-MS analysis was 1,6,10-dodecatrien-3-ol, 3,7,11-trimethyl- (nerolidol) with an activity score of 0.431. From LC-MS/MS analysis, 1,2,3,4-tetramethoxy-5-prop-2-enylbenzene showed the highest antioxidant potential (activity score 0.406). These findings demonstrate that P. hetheringtonii EUA-017 from Indonesian mangrove ecosystems produces diverse bioactive compounds with significant antioxidant potential. This study contributes to the discovery of natural antioxidants from mangrove-associated endophytic fungi and highlights the biotechnological potential of mangrove-derived fungal resources for pharmaceutical and nutraceutical applications.