title: High throughput screening and antioxidant assay of dibenzo[a,c]cyclooctadiene lignans in modified-ultrasonic and supercritical fluid extracts of Schisandra chinensis Baill by liquid chromatography--mass spectrometry and a free radical-scavenging method.
abstract: Dibenzo[a,c]cyclooctadiene lignans of Schisandra chinensis Baill are well known because of their hepatoprotective activity, antioxidant activity, and anticancer effect. For the isolation of the dibenzo[a,c]cyclooctadiene lignans of Schisandra chinensis Baill two extraction methods were used: modified-ultrasonic extraction and supercritical fluid extraction. A specific and fast analytical method for structure identification is established for quality control because structure elucidation could be accomplished by means of liquid chromatography-mass spectrometry (LC-MS) technologies. The separation and identification of the compounds were completed by: (i) a water-acetonitrile gradient system using a C18 reversed-phase column; (ii) UV detection at 225 nm; (iii) MS/MS experiments with electrospray ionization interface (ESI) ion trap mass spectrometry in the positive mode. Normalized collision energy was used to obtain fragment ions of structural relevance in the LC-MS/MS. These results provided a reliable LC-MS/MS method for the determination of the dibenzo[a,c]cyclooctadiene lignans from Schisandra chinensis Baill. Finally, we also detected 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging effects (%) of the modified-ultrasonic and supercritical fluid extracts of Schisandra chinensis Baill compared with 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). The antioxidant activities of the modified-ultrasonic and supercritical fluid extracts were lower than that of trolox.
authors.affiliation: Graduate School of Biotechnology, HungKuang University, Taichung, Taiwan, ROC.
authors.forename: Ming-Chih
authors.initials: MC
authors.lastname: Wang
authors.forename: Yih-Cherng
authors.initials: YC
authors.lastname: Lai
authors.forename: Chia-Lin
authors.initials: CL
authors.lastname: Chang
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D001713:Biphenyl Compounds / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D002839:Chromans / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D034242:Cyclooctanes / Q000032:analysis* / Q000302:isolation & purification*; D016166:Free Radical Scavengers; D005609:Free Radicals; D006834:Hydrazines / Q000737:chemistry; D017705:Lignans / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D010851:Picrates; D032141:Schisandra / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D014465:Ultrasonics
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002839:Chromans; D034242:Cyclooctanes; D016166:Free Radical Scavengers; D005609:Free Radicals; D006834:Hydrazines; D017705:Lignans; D010851:Picrates; C499589:dibenzo(a,c)cyclooctadiene; D002245:Carbon Dioxide; C004931:1,1-diphenyl-2-picrylhydrazyl; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid