ABSTRACT
OBJECTIVE@#To establish a high-performance liquid chromatographic method (HPLC) for the simultaneous determination of 16 compounds from Artemisia ordosica.@*METHODS@#HPLC was used to analyze 16 quality indicators of A. ordosica. The HPLC conditions were as follows: Agilent Eclipse Plus C18 column (250 mm × 4.6 mm, 5 μm) with acetonitrile (A)-water (B) as mobile phase, gradient elution: 0-10 min, 75%-65% B; 10-30 min, 65%-35% B; and finally 30-40 min, 35%-15% B. The flow rate was 1.0 mL/min, the column temperature was 40 °C, the injection volume was 10 μL, and monitored by absorbance at 285 nm for compounds 1- 10, 12 and 225 nm for compounds 11, 13- 16.@*RESULTS@#Under the selected experimental chromatographic conditions, compounds 1- 16 showed good linearity (r > 0.9993) in a wide concentration range. Their average recoveries were 99.50%, 95.38%, 97.75%, 96.00%, 98.20%, 97.50%, 95.50%, 99.33%, 96.75%, 96.50%, 98.50%, 97.83%, 99.20%, 95.33%, 97.33% and 96.30%, respectively, and the RSD were 1.99%, 1.81%, 1.63%, 1.98%, 1.67%, 1.92%, 1.74%, 1.67%, 1.90%, 1.72%, 1.88%, 1.83%, 1.79%, 1.76%, 1.81% and 1.96%, respectively.@*CONCLUSION@#Based on the results of the HPLC analysis, it was concluded that p-hydroxycinnamic acid ( 1), O-hydroxycinnamic acid ( 2), coniferyl alcohol ( 5), 5,4'-dihydroxy-7,3'-dimethoxyflavanone ( 8), 5,4'-dihydroxy-7-methoxyflavanone ( 9), 5-hydroxy-7,4'-dimethoxyflavanone ( 12), dehydrofalcarindiol ( 13), arteordoyn A ( 14), dehydrofalcarinol ( 15) and capillarin ( 16) are best suited for the role of quality indicators of A. ordosica grown in different ecological environments.
ABSTRACT
Objective To investigate the in vivo stress distribution of the atherosclerotic plaque at carotid bifurcation, so as to provide references for the mechanical mechanisms of plaque rupture at carotid bifurcation and the design for further medical treatment. Methods The three-dimensional geometric model of carotid bifurcation and plaque were established according to average geometric parameters of human carotid bifurcation. Residual stress of the carotid bifurcation and plague was reestablished with “thermal-structure” coupling method, and in vivo stresses of vessels with the plaque at carotid bifurcation under blood pressure and blood flow were calculated. Results Both the maximum principal stress and elastic shear stress concentrated on the shoulder of the plaque. Elastic shear stress increased with the increase of stenosis ratio and blood pressure. Wall shear stress in the upstream of the plaque was considerably higher than that of the downstream. The distribution of oscillatory shear index(OSI) was quite the opposite. The changing patterns of the elastic shear stress and flow shear stress were quite different with the change of stenosis ratios. Conclusions Tension grew gradually from the centrality to shoulder surface of the plaque. The centrality of the plaque might bear compression when the stenosis was very severe. The periodic variation of the structural stress might cause structural fatigue of the plaque, thus increasing the rupture risk. Distinction of the component and vulnerability of the plaque between upstream and downstream might be caused by differences in hemodynamic parameters of the plaque between upstream and downstream.
ABSTRACT
Objective To establish an HPLC method for the determination of seven flavonoids from the aerial part of Artemisia frigida.Methods Hypersil ODS-2 (300 mm× 4.6 mm,5 μm) column was used,with acetonitril-0.2％ phosphoric acid (gradient elution) as a mobile phase,and the detection wavelength was at 283 nm with flow rate at 1mL/min.Results All calibration curves showed good linear regression (r ＞ 0.9990) within the tested range.All average recovery was more than 98.00％ and RSD was less than 3.0％ (n =6).Conclusion The method is steady and with good repeatability,and could be used to determine the content of flavonoids in A.frigida from different areas.