Research On Stability And Antimicrobial Effect Of Toosendanin

Objective:Toosendanin possesses a wide spectrum of biological activities, among which therehave been many researches on anthelmintic and insecticidal efficacy. toosendanin is demonstrated to be a selective presynaptic blocker on neuromuscular junction and an effectively antibotulismic agent in previous studies. It can induce the cell differentiation, apoptosis and inhibition of varied tumor cells growth. Toosendanin is becoming a potential candidate as a bioactive substance in practical research on antibotulismic and antitumor effects. The stability may directly influence biological effect of toosendanin. In this paper, some influence factors such as temperature, water, solvent, light and pH were studied systematically. In addition, the bacterial inhibitory effect of it was investigated in four standard strains, such as Staphylococcus aureus (SA), Pseudomonas aeruginosa(PA), escherichia coli and Candida albicans. Laboratory observations of the minimal inhibitory concentration, the minimal bactericidal concentration, the bacteria-inhibiting ring and the bacteriostatic percentage were carried out according to the test procedures specified in《Disinfection Technical Guidelines》, 2002 ed and pharmacological experimental method. The results of this study could provide the fundamental pharmacodynamic data for the toosendanin application as an antimicrobialagent.Methods:1 .Extraction: Ultrasonic Wave-Assisted Extraction2.Determination: Ultraviolet-visible spectrophotometry was used for content determination of toosendanin.3.Stability: All kinds of factors affecting the stability of toosendanin, such as temperature, water, solvent, light and pH value, were determined.4.Bacteriostasis: The minimal inhibitory concentration and the minimal bactericidal concentration of toosendanin were measured by conventional agar dilution test. The diameter of bacteriostatic circle was studied with the slip method, and the curves of bacteriostasis for toosendanin against different species of bacteria were obtained using the Antimicrobial Percentage.Conclusion:1. In this paper, toosendanin was extracted by ultrasonic technique, using methanol as solvent. The method is time efficient, energy saving and the ratio of ultrasonic extraction is higher than soxhlet extraction.The influences of different solvents solid-liquid ratio, solvent volume temperature and ultrasonic time on the extraction rate of toosendanin were studied. The optimum extraction condition was obtained as follows: under the condition of 30℃, adding thirty times amount of methanol to the bark of toosendan , and extracting for 40 min and 4 times. Under the optimum condition.2. Toosendanin in crude extract was scanned in the range of 190～400nm and peak was found at 215nm. The recovery of standard addition and the precision of ultraviolet-visible spectrophotometry were methodologically studied. This method can be used for determination of toosendanin in crude extract with satisfactory results.3. The stability of toosendanin in methanol solutions was affected by temperature, polarity of the solvent, water, light and pH value. toosendanin was relatively stable at lower temperature. The stability decreased with the temperature increase. At the same temperature, the degradability of toosendanin increased with the prolonging of time and it increased more obviously at higher temperature. The stability decreased with increasing polarity of the solvents. The degradation process may be accelerated by water and the degradability increased with increasing amount of water. Toosendanin was stable in the weak acid condition. When the value of pH is around 4, toosendanin was most stable. Toosendanin degraded rapidly in strong acid and strong base, and easily degraded when exposed under light, with the degradability increasing with the prolonging of time.4. Toosendanin could inhibit Staphylococcus aureus (SA), Pseudomonas aeruginosa(PA), escherichia coli and Candida albicans. The minimum inhibitory concentration scope of toosendanin against the four standard strains was 7.5-30mg/mL, and the minimal bactericidal concentration scope was 15-30mg/mL. The higher the concentration of toosendanin, the better the bantibacterial effect was. Toosendanin is a promising bacteriostat.