In recent years, the study of endophytic fungi in traditional Chinese medicine has been drawing more and more attention from scholars around the globe. Secondary metabolites derived from these fungi have emerged as a rich source for uncovering structurally unique lead compounds. Strain LZC03 was obtained from freshly harvested common sage herb in Huangshan, Anhui Province, China. Through comprehensive morphological and molecular taxonomic analyses, it was determined to be Fusarium oxysporum. A novel compound, methyl 2-(4-((3-methylbut-2-en-1-yl)oxy)phenyl)acetyl)glycinate (1), together with a known compound, alternariol (2), were isolated and purified from the n-butanol fraction of the LZC03 fermentation product. Their structures were elucidated using 1D, 2D NMR and HRESI-MS techniques. The antioxidant and cytotoxic properties of both compounds were investigated. The findings indicated that both compound 1 and 2 exhibited cytotoxic and antioxidant capabilities. Compound 1 exhibited strong cytotoxicity and moderate antioxidant activity.