1 research outputs found
LC-MS- and <sup>1</sup>H NMR Spectroscopy-Guided Identification of Antifungal Diterpenoids from <i>Sagittaria latifolia</i>
Antifungal screening of small-molecule
natural product libraries
showed that a column fraction (CF) derived from the plant extract
of <i>Sagittaria latifolia</i> was active against the fungal
pathogen <i>Cryptococcus neoformans</i>. Dereplication analysis
by liquid chromatography–mass spectrometry (LC-MS) and proton
nuclear magnetic resonance spectroscopy (<sup>1</sup>H NMR) indicated
the presence of new compounds in this CF. Subsequent fractionation
of the plant extract resulted in the identification of two new isopimaradiene-type
diterpenoids, <b>1</b> and <b>2</b>. The structures of <b>1</b> and <b>2</b> were determined by chemical methods and
spectroscopic analysis as isopimara-7,15-dien-19-ol 19-<i>O</i>-α-l-arabinofuranoside and isopimara-7,15-dien-19-ol
19-<i>O</i>-α-l-(5′-acetoxy)arabinofuranoside,
respectively. Compound <b>1</b> exhibited IC<sub>50</sub> values
of 3.7 and 1.8 μg/mL, respectively, against <i>C. neoformans
and C. gattii</i>. Its aglycone, isopimara-7,15-dien-19-ol (<b>3</b>), resulting from acid hydrolysis of <b>1</b>, was
also active against the two fungal pathogens, with IC<sub>50</sub> values of 9.2 and 6.8 μg/mL, respectively. This study demonstrates
that utilization of the combined LC-MS and <sup>1</sup>H NMR analytical
tools is an improved chemical screening approach for hit prioritization
in natural product drug discovery