Overlapping elution-extrusion counter-current chromatography: a novel method for efficient purification of natural cytotoxic andrographolides from Andrographis paniculata.
Counter-current chromatography (CCC) is extremely useful for the separation, purification, and isolation of natural products. Recently, Berthod et al. established an elution-extrusion CCC method in metabolic analysis by combining regular chromatographic elution with stationary-phase extrusion, which extends the hydrophobicity window of a counter-current separation. In this study, a novel overlapping elution-extrusion CCC method was developed and applied to the preparation of natural cytotoxic andrographolides from the aerial parts of Andrographis paniculata, a well-known Traditional Chinese Medicine (TCM) with potent anti-inflammatory effect and anti-cancer activity. Its theory was first developed, and then a series of CCC experiments were performed to investigate the efficiency of the method in the separation of the ethanol extracts from A. paniculata. Results show that overlapping elution-extrusion CCC is an efficient method to prepare a cytotoxic natural diterpenoid combination of 14-deoxy-andrographolide and 14-deoxy-11,12-didehydroandrographolide with the molar ratio of 1:2 as well as andrographolide using an optimized solvent system composed of hexane-ethyl acetate-ethanol-water (5:5:4:6, v/v) with an on-demand solvent preparation mode. All components obtained showed potent cytotoxic activity against human hepatocellular liver carcinoma cells HepG2 and doxorubicin-resistant R-HepG2 cells. Molecular structures have been identified by electrospray ionization mass spectrometry (ESI-MS), electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), one- and two-dimensional nuclear magnetic resonance (1D- and 2D-NMR). The method appears to be very useful for the high-throughput purification of natural products.
Research Center of Siyuan Natural Pharmacy and Biotoxicology, College of Life Sciences Zhejiang University, Hangzhou 310058, China.
Dingfang
D
Wu
Xiaoji
X
Cao
Shihua
S
Wu
D035685:Andrographis / Q000737:chemistry*; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000302:isolation & purification* / Q000494:pharmacology; D003377:Countercurrent Distribution / Q000379:methods*; D004224:Diterpenes / Q000302:isolation & purification* / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy
D000893:Anti-Inflammatory Agents; D000970:Antineoplastic Agents; D004224:Diterpenes; C030419:andrographolide