title: On-line coupling of dynamic microwave-assisted extraction with high-speed counter-current chromatography for continuous isolation of nevadensin from Lyeicnotus pauciflorus Maxim.
abstract: An on-line method based upon dynamic microwave-assisted extraction (DMAE) coupled with high-speed counter-current chromatography (HSCCC) was developed for continuous isolation of nevadensin from Lyeicnotus pauciflorus Maxim. The DMAE parameters were optimized by means of the Box-Behnken design. The maximum extraction yield was achieved using 30:1 ml/g of liquid-solid ratio, 10 ml/min of solvent flow rate and 200 W of microwave power. The crude extracts were then separated by HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (7:3:5:5, v/v/v/v). 13.0mg of nevadensin was isolated from 15.0 g original sample by HSCCC with five times sample injection in 12h, and the isolation yield of nevadensin was 0.87 mg/g. The average purity of nevadensin was higher than 98.0%. The chemical structure of collected fraction was identified by HPLC, ESI-MS and (1)H NMR. The results indicated that this on-line method was effective and fast for high-throughput isolation of nevadensin from L. pauciflorus Maxim.
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Tong
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Xiao
authors.forename: Gongke
authors.initials: G
authors.lastname: Li
mesh_terms: D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D047309:Flavones / Q000302:isolation & purification*; D019684:Magnoliopsida / Q000737:chemistry*; D008872:Microwaves; D009862:Online Systems; D010936:Plant Extracts / Q000302:isolation & purification*
chemical_list: D047309:Flavones; D010936:Plant Extracts; C023982:nevadensin