Discovery of alkaloids from the leaves of Isatis indigotica Fortune with neuroprotective activity

Seven alkaloids including five undescribed ones (1a/1b, 2, 3 and 5) were obtained from the leaves of Isatis indigotica Fortune. Their structures were established by extensive spectroscopic analyses. The absolute configurations of compounds 1a, 1b, 3 and 5 were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Subsequently, the neuroprotective effects of all the isolates against H2O2-induced injury in SH-SY5Y cells were evaluated in vitro by MTT assay. Moreover, Annexin V-FITC/PI double staining was performed, while the activities of antioxidant enzymes (SOD, CAT and GSH-Px) for compounds 1a and 1b were measured.

Automated summary

Seven alkaloids, including five undescribed ones, were isolated from Isatis indigotica Fortune leaves. The structures and absolute configurations of the compounds were determined through extensive spectroscopic analyses and comparison of ECD spectra. Two of the isolates exhibited neuroprotective effects in vitro against H2O2-induced injury in SH-SY5Y cells.