A new flavonol glycoside isolated from the stems and leaves of <i>Astragalus membranaceus</i>

A new flavonol glycoside, namely astraside D, was isolated and characterised from the stems and leaves of <i>Astragalus membranaceus</i> (AMSL). Its structure was determined through comprehensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR. Building on our previous findings that AMSL alleviates memory impairment, we investigated the neuroprotective effect of astraside D on PC12 cells. However, the cytotoxicity assays demonstrated that astraside D manifested cytotoxicity throughout the concentration range from 5 to 100 μM, suggesting limited neuroprotective potential under the tested conditions. Subsequent investigation of its anti-inflammatory activity demonstrated significant inhibition of NO production in LPS-stimulated BV2 microglial cells, suggesting potential anti-inflammatory properties. These findings contribute to the growing understanding of the chemical diversity and bioactivity of AMSL, paving the way for further exploration of its therapeutic applications.