Simultaneous determination of plantainoside D and verbascoside from stem of Chirita longgangensis var. hongyao by RP-HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a RP-HPLC method for simultaneous determination of phenylethanoid glycosides plantainoside D and verbascoside in Chirita longgangensis var. hongyao.</p><p><b>METHOD</b>The analysis was performed on a Agilent C18 column (4.6 mm x 250 mm, 5 microm) with CH3CN-1% HAc (16:84)as mobile phase at a flow rate of 1.0 mL x min(-1), and at a column temperature of 30 degrees C. The detection wave length was 332 nm.</p><p><b>RESULT</b>The linear ranges of calibration of plantainoside D and verbascoside were 3.125-100.00 mg x L(-1) (r = 0.9998) and 25.00-500.0 mg x L(-1) (r = 0.9998). The average recoveries were 101.3% and 100.8% with RSD of 2.6% and 2.2% (n=9), respectively.</p><p><b>CONCLUSION</b>The method is simple, accurate, reliable and can be used for the quality evaluation of C. longgangensis var. hongyao and its preparation.</p>

Studies on the interaction between troxerutin and bovine serum albumin / 中国药理学通报

Aim To study the characteristics of the binding reaction of Troxetutin with bovine serum albumin (BSA) by fluorescence and ultra violet-visible absorption spectra.Methods The quenching mechanism of the fluorescence of BSA by troxerutin was studied with fluorescence.To determine the dynamic quenching constants and static binding constants,the Stern-Volmer equation and the double reciprocal Lineweaver-Burk equation were applied. The number of binding site was calculated with double logarithmic equation and the main binding force was discussed by thermodynamic equations. The binding distance and energy transfer efficiency between donor (BSA) and acceptor (troxerutin) were obtained effectively quenched fluorescence of BSA via static quenching processes. The binding constant Ka was calculated to be in the order of 106,indicating a strong interaction between Troxerutin and BSA. The number of binding site was approximately equal to 1,the binding distance was 1.97 nm,the energy transfer efficiency was 0.529,and the binding force was mainly hydrophobic force.Conclusion Troxerutin effectively quenchs the intrinsic fluorescence of BSA via static quenching mechanism,and the binding is mainly driven by the hydrophobic interaction.