Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from <em>Gymnosperma</em> <em>glutinosum</em> Leaves

Abstract

Bioassay-guided fractionation of hexane extracts of<em> Gymnosperma glutinosum</em> (Asteraceae) leaves, collected in North Mexico, afforded the known compounds hentriacontane (<strong>1</strong>) and (+)-13<em>S</em>,14<em>R</em>,15-trihydroxy-<em>ent</em>-labd-7-ene (<strong>2</strong>), as well as the new <em>ent</em>-labdane diterpene (−)-13<em>S</em>,14<em>R</em>,15-trihydroxy-7-oxo-<em>ent</em>-labd-8(9)-ene (<strong>3</strong>). In addition, D-glycero-D-galactoheptitol (<strong>4</strong>) was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the <em>in vitro</em> L5178Y-R lymphoma murine model. Hentriacontane (<strong>1</strong>) and the new <em>ent</em>-labdane <strong>3</strong> showed weak cytotoxicity, whereas the <em>ent</em>-labdane <strong>2</strong> showed significant (<em>p</em> < 0.05) and concentration dependent cytotoxicity (up to 78%) against L5178Y-R cells at concentrations ranging from 7.8 to 250 µg/mL.

Keywords

• &lt;em&gt;Gymnosperma glutinosum&lt;/em&gt;
• asteraceae
• Mexican medicinal plant
• lymphoma cells
• cancer
• &lt;em&gt;ent&lt;/em&gt;-Labdane diterpenes