<jats:p>Three new depsidones, botryorhodines E–G (<jats:bold>1</jats:bold>–<jats:bold>3</jats:bold>), and two new isoindolinones, meyeroguillines A and B (<jats:bold>7</jats:bold> and <jats:bold>9</jats:bold>), along with five known compounds were isolated from an endophytic fungus <jats:italic>Meyerozyma guilliermondii</jats:italic>, derived from the mangrove plant <jats:italic>Kandelia obovata.</jats:italic> Their structures were elucidated by 1D and 2D NMR spectroscopy and high resolution mass spectrometry (HREIMS). Compounds <jats:bold>1</jats:bold>–<jats:bold>6</jats:bold> exhibited strong α-glucosidase inhibitory activity with IC<jats:sub>50</jats:sub> values ranging from 2.1 to 13.3 μM. Moreover, kinetic studies of compounds <jats:bold>2</jats:bold> and <jats:bold>6</jats:bold> showed that both of them were noncompetitive inhibitors of α-glucosidase.