Deodeokaloid, a New Indole Alkaloid N-Glycoside and Bioactive Phenolic Compounds from the Roots of Codonopsis lanceolata

Codonopsis lanceolata, commonly known as the bonnet bellflower or deodeok, is primarily found in Eastern Asia. Its roots have been used traditionally across Asia to treat various ailments such as bronchitis, coughs, asthma, and inflammation. In our ongoing efforts to discover bioactive natural products, a phytochemical investigation of the n-BuOH fraction of C. lanceolata root extracts led to the isolation and identification of a new indole alkaloid N-glycoside, deodeokaloid (D-indole-3-lactic acid N-β-D-glucopyranoside) (1), alongside known compounds tangshenoside I (2), tangshenoside IV (3), and chlorogenic acid (4) through HPLC purification. The structure of the new compound 1 was elucidated using 1D and 2D NMR spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). Its absolute configuration was determined through a combination of DP4+ probability analysis and chemical reactions. The isolated compounds 1–4 were evaluated for their anti-Helicobacter pylori and antioxidant activities. In the anti-H. pylori assay, compound 3 showed antibacterial activity similar to that of quercetin as the positive control, inhibiting the bacterial growth by 36.8%. Compound 4 exhibited the most potent antioxidant activity, with an ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging activity of 1624.7 mmol TE/mol and a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging capacity of 707.5 mmol Trolox equivalent (TE)/mol. Compounds 2–4 displayed significant intracellular reactive oxygen species (ROS) scavenging capacity in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. This study highlights C. lanceolata roots as a promising natural source of bioactive compounds with potential therapeutic applications.