A new coumarin from the roots of <i>Micromelum minutum</i>

<p>A new coumarin, minutuminolate (<b>1</b>), together with eleven known coumarins (<b>2</b>–<b>12</b>), was isolated from the roots of <i>Micromelum minutum</i>. The structures of these compounds were established on the basis of their 1D and 2D NMR spectroscopic data. Compounds <b>2</b>, <b>5</b>, <b>10</b>, <b>11</b> and <b>12</b> showed cytotoxicity against KB cell line. In addition, compounds <b>2</b>, <b>3</b>, <b>4</b>, <b>7</b>, <b>11</b> and <b>12</b> also showed weak cytotoxicity against NCI-H187 cell line.</p

Chemical constituents from <i>Microstachys chamaelea</i> (Euphorbiaceae) with cytotoxic and antioxidant properties

Phytochemical investigation of Microstachys chamaelea led to the isolation and identification of fourteen known compounds after analysis of spectroscopic data. They consist of eight flavonoids (1–8), two benzoic acid derivatives (9–10), one brevifolin carboxylic acid derivative (11), one geraniinic acid derivative (12), shikimic acid (13), and β-daucosterol (14). Remarkably, it is the second isolation of compound 12 from a natural source. Several isolates were evaluated against ten cancer cell lines and on a set of targets involved in oxidative stress, as no such assays were undertaken in previous works. Compound 7 showed moderate to strong cytotoxicity against eight cell lines (IC50 values of 6.0–39.0 µM), while compounds 2, 8, and 11 showed weak to moderate cytotoxicity. Compounds 1–3, 5, and 11–12 showed moderate to strong DPPH and XXO inhibitory activities (IC50 values of 13.1–16.5 and 6.0–69.0 µM, respectively).</p