A Strategy for Preparative Separation of 10 Lignans from Justicia procumbens L. by High-Speed Counter-Current Chromatography

Ten compounds, including three lignan glycosides and seven lignans, were purified from L. in 8 h using an efficient strategy based on high-speed counter-current chromatography (HSCCC). The two-phase solvent system composed of petroleum-ethyl acetate-methanol-H₂O (1:0.7:1:0.7, / ) was firstly employed to separate the crude extract (320 mg), from which 19.3 mg of justicidin B ( ), 10.8 mg of justicidin A ( ), 13.9 mg of 6'-hydroxyjusticidin C ( ), 7.7 mg of justicidin E ( ), 6.3 mg of lignan J₁ ( ) were obtained with 91.3 mg of enriched mixture of compounds - . The enriched mixture (91.3 mg) was further separated using the solvent system consisting of petroleum-ethyl acetate-methanol-H₂O (3:3.8:3:3.8, / ), yielding 12.1 mg of procumbenoside E ( ); 7.6 mg of diphyllin-1- -β-d-apiofuranoside ( ); 7.4 mg of diphyllin ( ); 8.3 mg of 6'-hydroxy justicidin B ( ); and 7.9 mg of diphyllin acetyl apioside ( ). The purities of the 10 components were all above 94%, and their structures were identified by NMR and ESI-MS spectra. The results demonstrated that the strategy based on HSCCC for the separation of lignans and their glycosides was efficient and rapid.