| Summary: | Four new triterpenoids, 3β,12β,16β,21β,22-pentahydroxyhopane (<b>1</b>), 12β,16β,21β,22-tetrahydroxyhopan-3-one (<b>2</b>), 3-oxo-olean-12-ene-28,30-dioic acid (<b>3</b>), and 3β-hydroxyoleana-11,13(18)-diene-28,30-dioic acid 30-methyl ester (<b>4</b>); 21 new triterpenoid saponins, glinusopposides A−U (<b>5</b>−<b>25</b>); and 12 known compounds (<b>26</b>−<b>37</b>) were isolated from the whole plants of <i>Glinus oppositifolius</i>. The structures of the new compounds were elucidated based on the analysis of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. All compounds from the plants were measured for antifungal activities against <i>Microsporum gypseum</i> and <i>Trichophyton rubrum</i>. Glinusopposide B (<b>6</b>), glinusopposide Q (<b>21</b>), glinusopposide T (<b>24</b>), and glinusopposide U (<b>25</b>) showed strong inhibitory activities against <i>M. gypseum</i> (MIC<sub>50</sub> 7.1, 6.7, 6.8, and 11.1 μM, respectively) and <i>T. rubrum</i> (MIC<sub>50</sub> 14.3, 13.4, 11.9, and 13.0 μM, respectively). For those active compounds with an oleanane skeleton, glycosylation (<b>21</b>−<b>26</b>) or oxidation (<b>3</b>) of 3-OH was helpful in increasing the activity; replacement of the 30-methyl group (<b>29</b>) by a carboxymethyl group (<b>26</b>) enhanced the activity; the presence of 11,13(18) double bonds (<b>20</b>) decreased the activity.
|
|---|
