Flavonoid glycosides from Limonium coralloides (Tausch) Lincz and their antidiabetic and antineuroinflammation activities.

Investigations into the chemical constituents of Limonium coralloides (Tausch) Lincz result in the isolation of 10 previously undescribed compounds, including two acetylated flavonoid glycosides, three dihydroflavone glycosides, and five other flavonoid glycosides, along with 10 known flavonoid glycosides. The planar structures of the 10 undescribed flavonoid glycosides are determined using extensive spectroscopic techniques, including ultraviolet spectroscopy, high-resolution electrospray ionization mass spectrometry, and one-dimensional and two-dimensional nuclear magnetic resonance. The absolute configurations of the dihydroflavone glycosides are confirmed by comparing their calculated electronic circular dichroism data with experimental results. The configurations of the sugar moieties in these compounds are determined via gas chromatography-mass spectrometry analysis of acid-hydrolyzed, derivatized monosaccharides. More than half of the tested flavonoid glycosides exhibit notable inhibitory effects on protein-tyrosine phosphatase 1b, with half-maximal inhibitory concentration values below 6.26 μM. In addition, some flavonoid glycosides suppress lipopolysaccharide-induced nitric oxide release in BV-2 microglial cells, whereas others mitigate tert-butyl hydroperoxide-induced damage in H9c2 cells in vitro.