title: Optimisation and establishment of separation conditions of organic acids from Usnea longissima Ach. by pH-zone-refining counter-current chromatography: Discussion of the eluotropic sequence.
abstract: The major bioactive constituents of Usnea longissima Ach. are organic acids. However, few recent literatures involve the preparative separation of these organic acids. In the present study, pH zone-refining counter-current chromatography is used to separate organic acids from crude sample of U. longissima Ach. The crude extract was separated with the two-phase solvent system Pet-EtAc-MeOH-H2O (5:5:3:7, v/v) with 10mM TFA in organic stationary phase and different concentration of the eluter in aqueous mobile phase for the screening of the most suitable separation conditions. From the crude extract (1.2g), 74.0mg of orsellinic acid at 92.7% purity, 55.5mg of 4-O-methylorsellinic acid at 97.7% purity, 353.5mg of evernic acid at 93.8% purity, 102.0mg of barbatic acid at 94.8% purity, 19.4 mg of diffractaic acid at 92.2% purity, and 44.9 mg of usnic acid at 95.7% purity were obtained using the selected conditions in which the concentration of TFA in stationary phase was 10mM and the concentration of NaOH in mobile phase was 10-20mM. The purities of the separated organic acids were measured by HPLC. And the data of electrospray ionization-liquid chromatography/mass spectrometry (ESI-LC/MS), (1)H NMR, and (13)C NMR were used for confirming chemical structures.
authors.affiliation: Key Laboratory of TCM Quality Control Technology, Shandong Analysis and Test Center, Shandong Academy of Sciences, 19 Keyuan Street, Jinan, Shandong 250014, China; College of Pharmacy, Shandong University of Traditional Chinese Medicine, 4655 Daxue Street, Jinan, Shandong 250355, China.
authors.forename: Changlei
authors.initials: C
authors.lastname: Sun
authors.affiliation: Key Laboratory of TCM Quality Control Technology, Shandong Analysis and Test Center, Shandong Academy of Sciences, 19 Keyuan Street, Jinan, Shandong 250014, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory of TCM Quality Control Technology, Shandong Analysis and Test Center, Shandong Academy of Sciences, 19 Keyuan Street, Jinan, Shandong 250014, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.affiliation: College of Pharmacy, Shandong University of Traditional Chinese Medicine, 4655 Daxue Street, Jinan, Shandong 250355, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of TCM Quality Control Technology, Shandong Analysis and Test Center, Shandong Academy of Sciences, 19 Keyuan Street, Jinan, Shandong 250014, China. Electronic address: wangx@sdas.org.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
mesh_terms: D000840:Anisoles / Q000302:isolation & purification*; D001572:Benzofurans / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003377:Countercurrent Distribution / Q000379:methods; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates / Q000302:isolation & purification*; D010795:Phthalic Acids / Q000302:isolation & purification*; D012118:Resorcinols / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization; D020949:Usnea / Q000737:chemistry*
chemical_list: D000840:Anisoles; D001572:Benzofurans; D062385:Hydroxybenzoates; D010795:Phthalic Acids; D012118:Resorcinols; C509225:barbatic acid; C073339:usnic acid; C501612:orsellinic acid; C093528:diffractaic acid; C050847:evernic acid
keywords: Eluotropic sequence; Organic acids; Usnea longissima Ach.; pH-zone-refining counter-current chromatography