[A new alkaloids isolated from tetraploidy banlangen].

AIM: To investigate the chemical constituents of tetraploidy Banlangen (Isatis indigotica Fort.). METHODS: Compounds were separated by chromatography on silica gel. Their structures were determined by spectral analysis and chemical evidence. RESULTS: Three compounds were isolated. Their structures were identified as (E)-2-[(3'-indole) cyanomethylene]-3-indolinone (I), 2-(4-hydroxy-3-methoxyphenyl)-4-[(4-hydroxy-3-methoxy-phenyl)-methyl]-3- hydroxymethyl-tetrahydro-furan (II) and 2-methoxy-4-[tetrahydro-4-[(4-hydroxy-3-methoxy-phenyl)-methyl]-3- hydroxymethyl-2-furanyl] phenyl-1-O-beta-D-glucopyranoside (III). CONCLUSION: Compound I is a new compound.