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Three new metabolites, furobenzotropolones A, B (<b>1</b>–<b>2</b>) with unusual benzene and dihydrofuran moieties and 3-hydroxyepicoccone B (<b>3</b>), together with seven known compounds (<b>4</b>–<b>10</b>) were obtained from the endophytic fungus <i>Epicoccum nigrum</i> MLY-3 isolated from the fresh leaf of mangrove plant <i>Bruguiear gymnorrhiza</i> collected from Zhuhai. Their structures were assigned by the analysis of UV, IR, NMR, and mass spectroscopic data. Compound <b>1</b> was further confirmed by single-crystal X-ray diffraction experiment using Cu K<i>α</i> radiation. In antioxidant activities in vitro, compounds <b>2</b>, <b>3</b>, <b>5</b>, and <b>8</b> showed promising DPPH· scavenging activity with IC₅₀ values ranging from 14.7 to 29.3 µM. Compounds <b>2</b>, <b>3</b>, <b>5</b>, <b>7</b>, and <b>8</b> exhibited promising potent activity in scavenging ABTS· with IC₅₀ values in the range of 18–29.2 µM, which was stronger than that of the positive control ascorbic acid (IC₅₀ = 33.6 ± 0.8 µM).