Four new indole alkaloids from the roots ofIsatis tinctoria

Chemical fractionation of the ethanolic extract of the roots ofIsatis tinctoriaL. (I. tinctoria) yielded fourteen indole alkaloids including four new ones, isatisindigoticanine L-N and isatindigoside M. Their structures were established on the basis of extensive spectroscopic techniques including NMR, HRESIMS and IR as well as chemical methods. The absolute configuration of1was confirmed by ECD experiments. All the compounds were tested for their inhibitory effects on NO production in mouse mononuclear macrophages (RAW264.7) induced by lipopolysaccharide (LPS). The results showed that only compound5exhibited inhibitory effects with IC(50)value of 18.5 mu M.

Automated summary

Fourteen indole alkaloids, including four new compounds, were isolated from the ethanolic extract of the roots of Isatis tinctoria L. Their structures were determined using various spectroscopic techniques and chemical methods, with compound 5 showing inhibitory effects on NO production in mouse mononuclear macrophages.