Abstract:

Objective：To investigate in vitro antibacterial activity of the alcohol extracts and extract fractions of Rubus delavayi.
Methods：5 extract fractions were obtained through 95% ethanol reflux by extracting Rubus delavayi. The minimum inhibitory
concentration（MIC）, the minimum bactericidal concentration（MBC）and the inhibition zone of the crude extract and 5 extract
fractions were determined by tube dilution and disk diffusion method. The antibacterial activity of Rubus delavayi was observed.
Results：The alcohol extracts, its ethyl acetate fraction and its N-butanol fraction of Rubus delavayi showed high antibacterial activity
against eight tested bacteria; lower antioxidant activity was observed in the water fraction; the chloroform fraction had a significantly
inhibitory effect on Staphylococcus aureus, Proteusbacillus species, Bacillus subtilis and Salmonella typhi; the petroleum ether fraction
had a certain inhibition on Staphylococcus aureus and Bacillus subtilis. Conclusion: The alcohol extracts and its different extract
fractions of Rubus delavayi have in vitro antibacterial activity against almost all the studied bacteria.

Key words: Rubus delavayi, tube dilution, disk diffusion, in vitro antibacterial activity