Dihydroaurones and Isoflavan Derivatives from theRoots of <i>Glycyrrhiza asymmetrica</i>

As a continuation of our pharmacognostic studies on different <i>Glycyrrhiza</i> species growing in Türkiye, the phytochemical investigation of the roots of <i>Glycyrrhiza asymmetrica</i> Hub.-Mor., a licorice species endemic to Türkiye, was carried out. This study yielded twenty-three secondary metabolites (<b>1</b>–<b>23</b>) including nine previously unreported compounds: two dihydroaurone-3-enoic acids, licoaurone A (<b>1</b>) and licoaurone B (<b>2</b>), isoflavan hydroxypreglabridin (<b>3</b>), isoflavanone cyclodeoxykievitone (<b>4</b>), flavanone-3-ol glycyasymmetrol (<b>5</b>), and four bi-isoflavans, glycyasymmetrica A–D (<b>6</b>–<b>9</b>). The structures of isolated compounds were established by NMR and MS experiments. The relative configurations (<b>6</b>–<b>9</b>) were assigned by a combined quantum mechanical/NMR approach, comparing the experimental ¹³C/¹H NMR chemical shift data and the related predicted values. The absolute configurations of compounds <b>1</b>–<b>9</b> were assigned by comparison of their experimental electronic circular dichroism curves with the TDDFT-predicted curves. All isolated compounds were also evaluated for their cytotoxic activity against MCF-7, HeLa, HepG2, and A549 cancer cell lines by using MTT assay.