Fusarium verticillioides is one of the pathogenic fungi causing maize ear rot, and its secreted fumonisins accumulated in plants pose significant threats to human health. To reduce the incidence of maize ear rot and fumonisin contamination, this study isolated numerous endophytic fungi from maize plants. Through inhibition zone and dual culture assays, an endophytic fungal strain, FJ284, demonstrating notable antifungal activity against F. verticillioides was screened. 18S rDNA gene sequencing was employed for fungal identification, and the sequences were deposited in NCBI GenBank. FJ284 was identified as Penicillium oxalicum. The ethyl acetate extract of P. oxalicum was analyzed using gas chromatography–mass spectrometry (GC-MS), revealing 52 compounds, including several secondary metabolites with documented anticancer, antimicrobial, and antioxidant activities. Furthermore, a spectroscopic method was developed to assess the inhibitory effect of strain FJ284 against F. verticillioides, showing maximum inhibition at 48 h. Finally, Ultra-High-Performance Liquid Chromatography–Mass Spectrometry (UHPLC-MS) analyses confirmed that FJ284 significantly inhibited three fumonisins (suppression rates > 50%), with efficacy ranked as fumonisin B3 (FB3) > fumonisin B2 (FB2) > fumonisin B1 (FB1).

The Compendium of Materia Medica highlights the therapeutic properties of Trypoxylus dichotomus (T. dichotomus). In this study, the species and content of volatile components, inorganic elements, and amino acids were measured, and the activity of crude extracts of ethanol and water was studied. GC-MS analysis revealed 37–53 components across different life stages, excluding excessive heavy metals and containing essential trace elements. Amino acid profiling identified 15 types, rich in seven medicinal varieties. The in vitro anti-tumor testing of ethanol extracts from T. dichotomus adult males (TDA (M)) and T. dichotomus adult females (TDA (F)) was also performed. The experimental results showed that TDA (M) exhibited growth inhibition rates of 86.22% ± 1.19%, 85.42% ± 0.63%, 88.15% ± 3.27%, and 97.23% ± 0.60% against MKN-45, K-562, 239T, and 5637 tumor cells, respectively, while TDA (F) showed 81.28% ± 5.06% inhibition against K-562 cells. TDA best protected cells induced by H₂O₂ at the concentration of 12.5 μg/mL, achieving a cell survival rate of 81%. Overall, TDA, TDA(F), and TDA(M) have notable anti-tumor and antioxidant activity, highlighting the significance of chemical analysis for their potential bioactivity.