Abstract:

The separation of flavonoid from the crude extract of Ampelopsis grossedentata (FAG) by ultrafiltraion was
optimized using single factor and orthogonal experiments. The independent variables were ultrafiltration time, feed
concentration, temperature and pressure, and the responses were membrane flux and flavonoid purity. Furthermore, the
bacteriostatic activity of FAG containing 60% flavonoid was studied. The results showed that when the ultrafiltration
of the sample containing 0.5 mg/mL flavonoid at 35 ℃ was conducted at 0.2 MPa, the initial membrane flux was
0.215 mL/(cm2·min), yielding an increase in FAG purity from 32.7% to 60.1%. After ultrafiltration, FAG exhibited obvious
inhibitory effects on 4 kinds of bacteria with minimal inhibitory concentration (MIC) values of 0.75, 1.50, 1.50 and 3.00 mg/mL
and minimal bactericidal concentration (MBC) values of 0.75, 3.00, 3.00 and 3.00 mg/mL for Salmonella, Pseudomonas
aeruginosa, Staphylococcus aureus, and Escherichia coli, respectively.

Key words: flavonoid from Ampelopsis grossedentata (FAG), ultrafiltration, membrane flux, purity, bacteriostasis