Isolation and <i>In Vitro</i> Biological Evaluation of Triterpenes from <i>Salacia grandifolia</i> Leaves.

Abstract

<i>Salacia grandifolia</i> is naturally found in the Atlantic Forest regions of Brazil. Despite the pharmacological potential of plants from the <i>Salacia</i> genus, phytochemical studies on this species have not been reported in literature. A new triterpene, 28-hydroxyfriedelane-3,15-dione (<b>1</b>), and seven known compounds (friedelan-3-one (<b>2</b>), friedelan-3β-ol (<b>3</b>), friedelane-3,15-dione (<b>4</b>), 15α-hydroxyfriedelan-3-one (<b>5</b>), 28-hydroxyfriedelan-3-one (<b>6</b>), 30-hydroxyfriedelan-3-one (<b>7</b>), and 29-hydroxyfriedelan-3-one (<b>8</b>)) were obtained from the hexane extract of <i>Salacia grandifolia</i> leaves. These isolated compounds and three extracts, hexane (<b>EH</b>), chloroform (<b>EC</b>), and ethyl acetate (<b>EAE</b>), were assessed for their potential biological activities, which consisted in the evaluation of antiviral activity against a murine coronavirus, mouse hepatitis virus 3 (MHV-3), antibacterial activity against the susceptible and methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), and antileukemia activity against the THP-1 and K-562 cell lines. The extracts <b>EH</b> and <b>EAE</b> along with the triterpenes <b>1</b> and <b>6</b> exhibited moderate to high antiviral activity, with emphasis on <b>6</b>, which presented an EC₅₀ value of 2.9 ± 0.3 μM. None of the compounds presented antibacterial activity against the tested strains. The evaluated compounds <b>1</b>, <b>4</b>, <b>6</b> and <b>7</b> exhibited low cytotoxic activity against the tested leukemia cell lines. Taken together, this study comprises an overview for the potential of the <i>Salacia grandifolia</i> biological activities, including a new isolated triterpene.