Analysis of three types of triterpenoids in tetraploid white birches(Betula platyphylla Suk.) and selection of plus trees

Betulin, oleanolic acid, and betulinic acid are naturally occurring pentacyclic triterpenoids that have significant medicinal value. Considerable amounts of these triterpenoids are available in the outer bark of white birch. In this study, we used ultrasound-assisted extraction （UAE） to extract triterpenoids from birch bark rapidly and with high efficiency. Using high performance liquid chro- matography （HPLC）, three types of triterpenoids were separated and detected. We examined the differences among triterpenoids extracted from diploid versus tetra- ploid white birch. Then, we used factor analysis to screen out tetraploid white birches with comprehensively excel- lent performance. The results indicate that the optimum conditions for extraction include the use of ethanol as an extraction solvent, a solid-to-liquid ratio of 0.1 g/10 ml, ultrasonic power set at 100 W, a temperature of 60 ℃ and an extraction time of 15 min. A reversed-phase C18 col- umn （4.6 mm × 250 mm × 5 μm） with a column tem- perature of 30 ℃ and the mobile phase composed of A （acetonitrile） and B （0.1% aqueous phosphoric acid, v/v） at a flow rate of 0.5 ml/min were used, and the detection wavelength was 195 nm. No significant difference wasobserved between diploid and tetraploid white birch in terms of the content of three types of triterpenoids （at a confidence level of 0.05）. As triterpenoid content, height, and DBH （diameter at breast height） are strongly interre- lated, we used factor analysis to evaluate all individuals, and we screened out six plus trees with excellent com- prehensive characters.

The ocular toxicity and pharmacokinetics of simvastatin following intravitreal injection in mice

AIM：To investigate the retinal toxicity and pharmacokinetics of simvastatin intravitreally injected into mice.METHODS：Forty-eight 6-8-week-old C57BL/6J mice were used in this study.Simvastatin was intravitreally injected into the right eye of each mouse;the left eye was injected with vehicle and was used as a control.Bilateral dark-adapted electroretinography（ERG）was performed 1 and 7d following injection.Histology was examined using a combination of light,fluorescence and electron microscopy.Highperformance liquid chromatography（HPLC）was used to determine the decay in the retinal simvastatin concentration.RESULTS：ERG revealed no significant changes in the simvastatin-injected eyes compared to control.Histologic studies showed normal retinal morphology in eyes injected with simvastatin up to a final vitreal concentration of 200μmol/L.No significant changes in the number of photoreceptors,bipolar cells or ganglion cells were found.The retinal simvastatin concentration decayed exponentially,with a half-life of 1.92-2.41h.CONCLUSION：Intravitreal injection of up to 200μmol/L simvastatin produced no signs of adverse effects in the mouse retina.Simvastatin reaches the retina shortly after intravitreal injectionand has a short half-life.

harmacokinetics of Tetramethylpyrazine Phosphate inHealthy and Blood Stasis Dogs in vivo

To test the hypotliesis of Syndrome and Treatment Pharmacokinetics (S-TPK ) , tlie authorsbeve stodied tlie pharmacokinetics of tetramethyrazine phosphate (TMPP) in healthy and blood stasis dogs byhigh performance liquid chromatography. After a single intravenous injection ot TMPP & mg` kg i to healthyand blood stasis dogs, compartment model of TMPP serum concontration was fitted and then pharmacokineticparameters were calculated with a Microcomputer Pharmacokinetic Program on a Compaq 80386 computer.lmportant parameters were as follows: in the healthy dogs, T1/2 = 30. 27 ±6. 85 min. Kel = 0. 11 ± 0. 04min-1 , AUC = 445. 26 ± 51 . 26 mg/L.min , in the blood stasis dogs, min, Kel = 0. 06±0 . 01 min -1 , AUC = 1381 . 85 ± 464 . 68 mg/L. min. Through this experiment it was found that there was sig-nificant differefico in the pharmacokinetic parameters between healthy and blood stasis dogs. The results ob-tained are consistent with S-TPK hypotbesis.