Four undescribed sulfur-containing indole alkaloids with nitric oxide inhibitory activities from Isatis tinctoria L. roots

• DOI: 10.1016/j.phytochem.2020.112337
• Publication Date: 2020-03-09T10:53:32Z
• Authors: Dongdong Zhang; Deqing Ruan; Jingyi Li; Zhaoqiang Chen; Weiliang Zhu; Fujiang Guo; Kaixian Chen; Yiming Li; Rui Wang
• Keywords: Molecular Structure; Biodiversity; Isatis; Nitric Oxide; Plant Roots; 01 natural sciences; Sulfur; Taxonomy; Indole Alkaloids; 3. Good health; 0104 chemical sciences

Four undescribed sulfur-containing indole alkaloids, isatisindigoticanines H, I and isatindigosides F, G along with three known analogues were obtained from Isatis tinctoria L. roots. Isatisindigoticanines H and I contained an unusual 1-(thiazol-4-yl)butane-1,2,3,4-tetraol moiety while isatindigosides F and G possessed a new 3-[3-(1H-indole-2-yl)azet-2-yl]-1H-indole skeleton. The putative biosynthetic pathways of isatisindigoticanines H, I and isatindigosides F, G are proposed. The isolated compounds showed nitric oxide inhibitory effects with IC50 values ranging from 4.3 to 70.3 μM.