Studies on chemical constituents from leaves of Isatis indigotica

Abstract

Objective: To study the chemical constituents of the leaves of Isatis indigotica. Method: The leaves of I. indigotica were extracted with 80% ethanol. The EtOH extract was dispersed in H2O and extracted with petroleum, EtOAc and BuOH successively. The EtOAc fraction was isolated and purified by column chromatography on silica gel, Sephadex LH -20 and Rp-8, Rp-18. All the compounds were identified on the basis of spectral analyses (including MS, 1H-NMR, 13C-NMR), Result: Eleven compounds were isolated from the leaves of I. indigotica, and structures were characterized as 10H-indolo [3, 2-b] quinoline (1), indirubin (2), 4 (3H)-quinazo-linone (3), (E)-3-(3′, 5′-dimethoxy-4′-hydroxybenzylidene)-2-indolinone (4), 2, 3-dihydropyrrolo [2, 1-b] quinazolin-9(1H)-one (5), benzoic acid (6), o-droxy-benzoic acid (7), (-)-lariciresinol (8), (+)-isolariciresinol (9), isovitexin (10), 6-β-D-glucopyranosyldiosmetin (11). Conclusion: 1, 4, 5, 8, 9, 11 were obtained from the leaves of I. indigotica for the first time.