title: HPLC-DAD method for comprehensive quality control of Semen Strychni.
abstract: BACKGROUND
  Semen Strychni is the seed of Strychnos nux-vomica L. (Loganiaceae). Its quality control procedure remains an issue since previous reports only focused on Strychnos alkaloids. To the best of our knowledge, chlorogenic acid (a phenolic acid) and loganin (an iridoid glycoside) are selected for the first time as marker constituents of quality control for Semen Strychni because of their bioactive activity correlating with therapeutic effects.
  
  
  OBJECTIVE
  This study aimed to develop a simple and comprehensive quantity control method for Semen Strychni.
  
  
  METHODS
  The optimal ultrasonic extraction procedure was carried out for 45 min using 50% aqueous methanol with 1% formic acid. The satisfactory chromatographic separation was achieved on an Ultimate LP-C18 column with gradient elution using acetonitrile and water containing 30 mmol/L ammonium acetate and 1% formic acid. The high performance liquid chromatography method with diode array detector was validated for linearity, limit of detection and quantification (LOQ), precision, repeatability, accuracy and stability.
  
  
  RESULTS
  All the calibration curves showed good linearity (r(2) ≥ 0.999). The LOQ values for chlorogenic acid, loganin, strychnine, brucine, strychnine N-oxide and brucine N-oxide were 0.54, 0.83, 0.48, 0.50, 0.52 and 0.54 μg/mL, respectively. The method was reproducible with good accuracy in the range 95.6-104.4% and relative standard deviation (RSD) values less than 4.55%. The method was then applied to determine the components of the seed coat, seed leaf, endosperm and whole seed of Semen Strychni.
  
  
  CONCLUSIONS
  This newly established method is validated as a simple and practical tool for authentication and quality control of Semen Strychni.
authors.affiliation: Clinical Pharmacy and Pharmacology Research Institute, Pharmaceutical Department, the Second Xiangya Hospital of Central South University , Changsha , China and.
authors.forename: Huai-Bo
authors.initials: HB
authors.lastname: Tang
authors.forename: Hua-Lin
authors.initials: HL
authors.lastname: Cai
authors.forename: Huan-De
authors.initials: HD
authors.lastname: Li
authors.forename: Lin-Jun
authors.initials: LJ
authors.lastname: Zhang
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Li
authors.forename: Ji-Hui
authors.initials: JH
authors.lastname: Tang
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Chen
mesh_terms: D002021:Buffers; D002138:Calibration; D002726:Chlorogenic Acid / Q000032:analysis* / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D004365:Drugs, Chinese Herbal / Q000032:analysis* / Q000592:standards; D039823:Iridoids / Q000032:analysis* / Q000592:standards; D057230:Limit of Detection; D016014:Linear Models; D029541:Loganiaceae / Q000737:chemistry; D008517:Phytotherapy; D010946:Plants, Medicinal; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D012639:Seeds; D012997:Solvents / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000592:standards
chemical_list: D002021:Buffers; D004365:Drugs, Chinese Herbal; D039823:Iridoids; D012997:Solvents; D002726:Chlorogenic Acid; C059516:loganin