High-Resolution Screening Combined with HPLC-HRMS-SPE-NMR for Identification of Fungal Plasma Membrane H⁺-ATPase Inhibitors from Plants

Abstract

Crude extracts of 33 plant species were assessed for fungal plasma membrane (PM) H(+)-ATPase inhibition. This led to identification of 18 extracts showing more than 95% inhibition at a concentration of 7.5 mg/mL and/or a concentration-dependent activity profile. These extracts were selected for semi-high-resolution fungal PM H(+)-ATPase inhibition screening, and, on the basis of these results, Haplocoelum foliolosum (Hiern) Bullock and Sauvagesia erecta L. were selected for investigation by high-resolution fungal PM H(+)-ATPase inhibition screening. Structural analysis performed by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-HRMS-SPE-NMR) led to identification of chebulagic acid (1) and tellimagrandin II (2) from H. foliolosum. Preparative-scale isolation of the two metabolites allowed determination of IC50 values for PM H(+)-ATPase, and growth inhibition of Saccharomyces cerevisiae and Candida albicans. Chebulagic acid and tellimagrandin II are both potent inhibitors of the PM H(+)-ATPase with inhibitory effect on the growth of S. cerevisiae.

High-Resolution α-Glucosidase Inhibition Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of Antidiabetic Compounds in Eremanthus crotonoides (Asteraceae)

“…high-resolution inhibition profiling [15][16][17]. Furthermore, the HR-bioassay/HPLC-HRMS-SPE-NMR platform has successfully been applied for identification of α-amylase inhibitors [18], fungal plasma membrane H + -ATPase inhibitors [19], antioxidants [20] and monoamine oxidase A inhibitors [21]. In our ongoing search for antidiabetic compounds from natural sources, Eremanthus crotonoides (DC.)…”

“…This is the first investigation of antidiabetic activity of an Eremanthus species, and it led to identification of six α-glucosidase inhibitors by high-resolution α-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR, i.e., four flavonoids (16, 17, 19, and 20) and two The biochromatogram shows that peaks 16,17,19, and 20 are correlated with α-glucosidase inhibitory activity of 82%, 23%, 32%, and 70%, respectively. For identification of the bioactive compounds, fraction Fr.2 was subjected to HPLC-HRMS-SPE-NMR analysis with trapping of peaks 13-20 after separation of ten successive injections; thereby ensuring high-quality NMR data for the trapped peaks.…”

“…For identification of the bioactive compounds, fraction Fr.2 was subjected to HPLC-HRMS-SPE-NMR analysis with trapping of peaks 13-20 after separation of ten successive injections; thereby ensuring high-quality NMR data for the trapped peaks. Based on HRMS as well as 1D and 2D NMR data (Table S1 in Supplementary Materials) obtained in the HPLC-HRMS-SPE-NMR mode, the peaks were identified as 3,5-di-O-caffeoylquinic acid ethyl ester (13) [39], 4,5-di-O-caffeoylquinic acid ethyl ester (14) [31], cis-tiliroside (15) [40], quercetin (16) [13], trans-tiliroside (17) [40], isorhamnetin-3-O-(6"-O-(E)-p-coumaroyl)-β-D-glucoside (18) [41], luteolin (19) [10] and quercetin 3-methyl ether (20) [34]. Peaks 15 and 18 were trapped in a separate HPLC-HRMS-SPE-NMR experiment with higher injection volumes in order to acquire HMBC data with sufficient high signal intensity (example of 1 H and heteronuclear HSQC and HMBC for compound 15 are given in Supplementary Materials Figure S1a-c).…”

“…From this perspective, the very recent development of state-of-the-art high-resolution bioassays combined with hyphenation of high-performance liquid chromatography, high-resolution mass spectrometry, solid-phase extraction and nuclear magnetic resonance spectroscopy [8], i.e., HR-bioassay/HPLC-HRMS-SPE-NMR has been an important tool for identification of α-glucosidase inhibitors from plant and food extracts [9][10][11][12][13][14]-including the development of dual and triple high-resolution inhibition profiling [15][16][17]. Furthermore, the HR-bioassay/HPLC-HRMS-SPE-NMR platform has successfully been applied for identification of α-amylase inhibitors [18], fungal plasma membrane H + -ATPase inhibitors [19], antioxidants [20] and monoamine oxidase A inhibitors [21].…”

High-resolution bioactivity profiling combined with hyphenated HPLC-SPE-NMR – Investigation of functional food and plants with antifungal constituents

“…[3]. In the second study, high-resolution plasma membrane H + -ATPase inhibition profiles were used for identifying antifungal compounds chebulagic acid and tellimagrandin II from Haplocuelum foliolosum [4].…”