Analysis of the components of <i>Cassia nomame</i> and their antioxidant activity

<i>Cassia nomame</i>, an annual herb belonging to the Leguminosae family, is traditionally consumed as tea in the form of dried whole herbs or beans. To deepen our understanding of the chemical constituents of <i>C. nomame,</i> we isolated 16 compounds, categorised as flavone derivatives (<b>1</b>-<b>4</b>), including a novel compound nomameflavone A (<b>4</b>), a chalcone derivative (<b>5</b>), an aurone derivative (<b>6</b>), a chromone derivative (<b>7</b>), a juglone derivative (<b>8</b>), anthraquinone derivatives (<b>9</b>-<b>11</b>), phenolic compounds (<b>12</b>-<b>14</b>), and sterol derivatives (<b>15</b>, <b>16</b>). The structure of each compound was elucidated using NMR and MS. Compounds <b>2</b>, <b>6</b>, <b>7</b>, <b>8</b>, <b>12</b>, <b>13</b>, and <b>14</b> were successfully isolated from <i>C. nomame</i> for the first time. Furthermore, compounds <b>1</b>, <b>3</b>, <b>5</b>, and <b>6</b> exhibited DPPH radical scavenging activities, and the bioactivity of <b>3</b> was discovered. The elucidation of the diverse chemical constituents of <i>C. nomame</i> underscores its potential functional ingredients.