[Enzymatic extraction and antibacterial activity of aucubin from Eucommia ulmoides leaves].

Objective: To investigate the technology of Aucubin in Eucommia ulmoides leaves extracted by enzymatic method and its antibacterial activity.

Methods: Aucubin in Eucommia ulmoides leaves was extracted by cellulase method. The extraction technology was optimized using the content of Aucubin as index. The antibacterial activity of Aucubin was determined.

Results: The results showed that the optimum technology was as follows; The solid-liquid ratio was 1:12, extracted for 50 min by 0.4% enzyme at 50 degrees C in pH 6.0. The extraction rate of Aucubin was as high as 17.892 mg/g. The Aucubin extracted could obviously inhibit the growth of Escherichia coli and Staphylococcus aureus, the MIC of Aucubin against Staphylococcus aureus and Escherichia coli were 4.832 mg/mL and 9.664 mg/mL respectively. However, Aucubin presented weak inhibitory effect on Streptococcus pneumonia and MG-hemolytic streptococcus, the MIC of Aucubin against them were all 28.946 mg/mL.

Conclusion: The extraction technology obtained in this experiment is reasonable and feasible with high extraction rate, and the Aucubin has some antibacterial activity.