Palhinosides A-H (<b>1</b>-<b>8</b>), new flavone glucosidic truxinate esters, including β-truxinate and μ-truxinate forms, were isolated from <i>Palhinhaea cernua</i>. Their structures were elucidated by extensive spectroscopic methods and chemical analyses. The flavone glucoside cyclodimers possess a unique cyclobutane ring in their carbon scaffolds. Compounds <b>2</b>-<b>7</b> represent three pairs of stereoisomers (<b>2/3</b>, <b>4/5</b>, <b>6/7</b>). The protective effects of <b>1</b>-<b>8</b> against the damage of HT-22 cells induced by l-glutamate were evaluated, and compounds <b>4</b> and <b>5</b> showed better neuroprotective effects than the positive control, Trolox.