ABSTRACT
Objective: To investigate the chemical constituents in flowers of Gentiana tibetica. Methods: The chemical constituents were isolated from the 95% alcohol extract of G. tibetica flowers by silica column chromatography, Sephadex LH-20, C18 and RP-HPLC. Their chemical structures were elucidated on the basis of IR, ESI-MS, 1H-MNR, and 13C-MNR spectroscopic data. Results: Twelve compounds, including chromene, flavones C-glycosides, secoiridoid glycosides, iridoid glycosides, aliphatic alcohol, and disaccharide, were obtained from the 95% alcohol extract of G. tibetica flowers, Their structures were identified as macrophylloside D (1), orientin 7-caffeate (2), 7-O-feruloylorientin (3), isovitexin (4), saponarin (5), isoorientin (6), 6'-O-β-D-glucopyranosyl gentiopicroside (7), sweroside (8), swertiamarine (9), loganic acid (10), 1-heneicosanol (11), and sucrose (12). Conclusion: Compounds 1-12 are isolated from G. tibetica for the first time.
ABSTRACT
Objective: To establish an HPLC method for simultaneously determining seven components, such as loganic acid, 6′-O-β-D-glucopyranosyl gentiopicroside, swertiamarine, gentiopicroside, swertiamarin, isoorientin, and isovitexin, from the flowers of Gentiana tibetica and G. dendrology. Methods: Chromatographic analysis was achieved on an Agilent Zorbax ODS column (150 mm × 4.6 mm, 5 μm) by gradient elution of acetonitrile-0.4% acetic acid in water at 30℃. The flow rate was 0.4 mL/min and the detection wavelength was 254 nm. Results: The calibration curves of all the seven constituents showed good linearity in a relatively wide concentration range. The linear ranges of loganic acid, 6′-O-β-D-glucopyranosyl gentiopicroside, swertiamarine, gentiopicroside, gentiopicroside, isoorientin, and isovitexin were 0.228-2.280, 0.680-6.800, 0.220-2.20, 1.476-14.760, 0.200-2.000, 0.436-4.360, and 0.276-2.760 μg (R2 ≥ 0.999 2), respectively. The recoveries (n = 9) of loganic acid, 6′-O-β-D-glucopyranosyl gentiopicroside, swertiamarine, gentiopicroside, gentiopicroside, isoorientin, and isovitexin were 100.9%, 99.4%, 101.0%, 105.7%, 103.1%, 98.4%, 104.2%. Conclusion: This method is simple, accurate, and specific, and can be used for the determination of seven constituents in the flowers of G. tibetica and G. dendrologi.