Phenolic compounds from the stems of <i>Flickingeria fimbriata</i>

<p>Chemical investigation of <i>Flickingeria fimbriata</i> (Bl.) Hawkes (Orchidaceae) resulted in the isolation and identification of one new dihydrophenanthrene, 1,2,5,6,7-pentamethoxy-9,10-dihydrophenanthrene (<b>1</b>), together with seven known dihydrophenanthrenes, erianthridin (<b>2</b>), coelonin (<b>3</b>), 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (<b>4</b>), lusianthridin (<b>5</b>), ephemeranthol A (<b>6</b>), flavanthridin (<b>7</b>) and hircinol (<b>8</b>), four known phenanthrenes, epheranthol B (<b>9</b>), nudol (<b>10</b>), denthyrsinin (<b>11</b>) and confusarin (<b>12</b>), and one known bibenzyl, batatasin III (<b>13</b>). The structure of the new compound was elucidated by spectroscopic analysis (HRMS, 1D and 2D NMR). All the compounds were isolated from <i>F. fimbriata</i> for the first time except for compounds <b>5</b> and <b>12</b>, and compounds <b>1</b>, <b>3</b>, <b>4</b>, <b>8</b>, <b>10</b>, <b>11</b> and <b>13</b> were obtained from this genus for the first time. Compounds <b>1</b>–<b>4</b> showed moderate cytotoxic activity against HepG2 cells.</p>