title: Simultaneous determination of three diarylheptanoids and an alpha-tetralone derivative in the green walnut husks (Juglans regia L.) by high-performance liquid chromatography with photodiode array detector.
abstract: By optimizing extraction, separation and analytical conditions, a reliable and accurate high-performance liquid chromatographic (HPLC) method coupled with photodiode array detector (DAD) at room temperature is developed for simultaneous determination of three diarylheptanoids (juglanin A, juglanin B, rhoiptelol) and an alpha-tetralone derivative (regiolone) in methanol extracts from the green walnut husks (Juglans regia L.) The sample pretreatment process involved the reflux extraction using methanol as the extract with a ratio of liquor to sample of 15 mL/g. The separation was achieved on a SinoChrom ODS-AP C(18) column with gradient elution using acetonitrile and 2% (v/v) acetic acid in water. The intra-day and inter-day precision (RSD%) for the analytes ranged from 1.08 to 1.51 and 0.60 to 1.13, respectively. The average recoveries obtained were from 88.4% to 96.2% for the analytes with RSDs below 3.13%. The correlation coefficients of the calibration curve exceeded 0.999. The detection limits were 0.51, 0.25, 0.32 and 0.35 ng at a signal-to-noise ratio of 3, respectively. Quantitative analyses of the samples from different grown sites and in obtained different months showed that the contents of the analytes varied significantly. The method was then successfully applied for the detection and isolation of a new diarylheptanoid derivative in the green walnut husks (J. regia L.). The structure of the new compound was elucidated by various spectroscopic methods including 2D NMR techniques (COSY, HMQC, HMBC), HR-ESI-MS and X-ray single-crystal diffraction analysis.
authors.affiliation: Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, tianshuizhonglu No. 18, Lanzhou 730000, Gansu, China.
authors.forename: Junxi
authors.initials: J
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Meng
authors.forename: Chen
authors.initials: C
authors.lastname: Li
authors.forename: Xinyi
authors.initials: X
authors.lastname: Huang
authors.forename: Duolong
authors.initials: D
authors.lastname: Di
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018360:Crystallography, X-Ray; D036381:Diarylheptanoids / Q000032:analysis* / Q000737:chemistry; D031324:Juglans / Q000737:chemistry*; D015394:Molecular Structure; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet; D044024:Tetralones / Q000032:analysis* / Q000737:chemistry
chemical_list: D036381:Diarylheptanoids; D044024:Tetralones