Bioactivity-Guided Isolation of Antistroke Compounds from Gymnadenia conopsea (L.) R. Br.

A bioactivity-guided separation strategy was used to identify novel antistroke compounds from <i>Gymnadenia conopsea</i> (L.) R. Br., a medicinal plant. As a result, 4 undescribed compounds (<b>1-2</b>, <b>13</b>, and <b>17</b>) and 13 known compounds, including 1 new natural product (<b>3</b>), were isolated from <i>G. conopsea.</i> The structures of these compounds were elucidated through comprehensive spectroscopic techniques, such as 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS), and quantum chemical calculations. An oxygen-glucose deprivation/reoxygenation (OGD/R)-injured rat pheochromocytoma (PC12) cell model was used to evaluate the antistroke effects of the isolates. Compounds <b>1-2</b>, <b>10-11</b>, <b>13-15</b>, and <b>17</b> provided varying degrees of protection against OGD/R injury in the PC12 cells at concentrations of 12.5, 25, and 50 µM. Among the tested compounds, compound <b>17</b> demonstrated the most potent neuroprotective effect, which was equivalent to that of the positive control drug (edaravone). Then, transcriptomic and bioinformatics analyses were conducted to reveal the regulatory effect of compound <b>17</b> on gene expression. In addition, quantitative real-time PCR (qPCR) was performed to verify the results of the transcriptomic and bioinformatics analyses. These results suggest that the in vitro antistroke effect of compound <b>17</b> may be associated with the regulation of the <i>Col27a1</i> gene. Thus, compound <b>17</b> is a promising candidate for the development of novel antistroke drugs derived from natural products, and this topic should be further studied.