Alkaloids from the <i>Pleurotus tuoliensis</i> and their anti-gastric cancer activity

Eleven alkaloids (<b>1–11</b>) including four new ones tuoliensines A-D (<b>1-4</b>) were isolated from the fruiting body of <i>Pleurotus tuoliensis</i> using 95% ethanol heating reflux extraction. Their structures characterisation through chemical and spectral analyses classified these compounds as indole, pyridazine, and pyrrole alkaloids. The absolute constructions of the new compounds were identity by comparing computational and experimental electron circular dichroism (ECD) data. Furthermore, The antitumor activity of compounds <b>1-11</b> was analysed against HGC-27 cell line. The findings revealed that compound <b>5</b> had a significant inhibitory effect with an IC₅₀ value of 1.93 µM, which is superior to that of cisplatin (2.58 ± 0.17 µM). Additionally, compounds <b>1-4</b> displayed promising HGC-27 cell inhibition with IC₅₀ values of 11.14, 8.53, 10.68, 3.89 µM.