Antibacterial Dimeric Acylphloroglucinols from <i>Hypericum japonicum</i>

Nine dimeric acylphloroglucinols, including the new hyperjaponicols A–D (<b>1</b>–<b>4</b>), were isolated from the whole plant of <i>Hypericum japonicum</i>. The new structures were determined by the interpretation of NMR and MS data, and the relative configuration of the known compound, sarothralen C (<b>5</b>), was reassigned via NMR spectroscopic analysis and single-crystal X-ray diffraction data. The inhibitory activities of the isolates against four bacterial strains were evaluated, and compounds <b>1</b>–<b>4</b>, <b>6</b>, and <b>7</b> exhibited significant antibacterial activity with MIC values of 0.8–3.4 μM. In addition, compound <b>3</b> showed moderate lipase inhibitory activity (IC₅₀ 8.3 μM)