ABSTRACT
A cycledextrin-modified micellar electrokinetic chromatography technique for separating and determination oleanolic acid and ursolic acid in the fruit of Cornus officinalis was developed. The two bio-active components was completely separated using a buffer containing 60 mmol/L SDS, 2.5 mmol/L NaH2PO4, 2.5 mmol/L Na2B4O7, 8 mmol/L DM beta-CD,8 mmol/L beta-CD and 30% (v/v) 2-propanol. The correlation cofficients of the linear calibration graphs for oleanolic acid and ursolic acid are 0. 9996 and 0.9995, respectively. The effects of SDS, 2-propanol, dimethyl-beta-cyclodextrin, beta-cyclodextrin, NaH2PO4, Na2B4O7 and pH on separation were investigated.
Subject(s)
Cornus/chemistry , Electrophoresis, Capillary/methods , Oleanolic Acid/isolation & purification , Plants, Medicinal/chemistry , Triterpenes/isolation & purification , 2-Propanol/chemistry , Hydrogen-Ion Concentration , Molecular Structure , Oleanolic Acid/analysis , Oleanolic Acid/chemistry , Reproducibility of Results , Sodium Dodecyl Sulfate/chemistry , Triterpenes/analysis , Triterpenes/chemistry , beta-Cyclodextrins/chemistry , Ursolic AcidABSTRACT
8-hydroxy-2'-deoxyguanosine (8OHdG) has been widely used as a biomarker of oxidative DNA damage in both animal models and human studies. To evaluate the effect of cigarette smoking on oxidative stress, we studied the levels of urinary 8OHdG from smokers and non-smokers and investigated the association with cigarette smoking. The urinary 8OHdG concentrations were determinated by capillary electrophoresis with end-column amprometric detection (CE-AD) after a single-step solid phase extraction (SPE), and then quantitatively expressed as a function of creatinine excretion. To increase the concentration sensitivity, a dynamic pH junction was used and the focusing effect was obvious when using 30mM phosphate (pH 6.50) as sample matrix. The limit of detection is 4.3nM (signal-to-noise ratio S/N=3). The relative standard deviation (R.S.D.) was 1.1% for peak current, and 2.3% for migration time. Based on the selected CE-AD method, it was found that the mean value of urinary 8OHdG levels in the smokers significantly higher than that in non-smokers (31.4+/-18.9 nM versus 14.4+/-7.6 nM , P=0.0004; 23.5+/-21.3 mug g (-)(1) creatinine versus 12.6+/-13.2 mug g (-)(1) creatinine, P=0.028).
