Antimicrobial Effects Of Vitex Negundo Linn. Stem

The resources of Chinese Herb Medicine are really rich. It's one of the hot spots to extract antimicrobial substances from plants by looking for natural activated substances, then directly use plant extracts as food additives, or synthesizing new compounds according to the structure of natural active substances. As a kind of widely spread plant in our country, Vitex negundo Linn. contains excellent officinal effects. However, it's rarely used in food preservation. By doing research its antimicrobial effects, we can take a further study on its applications, turn waste in to treasure and make a good economical effects.In this paper, antimicrobial effects of Vitex negundo Linn. stem and its application were studied. Chloroform, 50% ethanol, 95% ethanol and water were used to extract plant stem by four different methods (Vibration, Ultrasound, Water boiling, Suo extraction ). Antimicrobial effects were tested against Staphylococcus aureus, Escherichia coli., Bacillus subtilis, Saccharomyces cerevisiae, Penicillium sp. And Aspergillus sp.. The results showed that Vitex negundo Linn. stem's 95% ethanol extracts exhibited the best antibacterial effects to Staphylococcus aureus. However, no significant difference was found on the various extraction methods.The extracts from Vitex negundo Linn. stem were primarily separated by column chromatography with D3520 macroporous resin. Antibacterial effects of separations to Staphylococcus aureus was studied. The results showed that the inhibitory effects on bacterial of the extracts used in our experiments were influenced by the polar of solvents, and the strong polar solvent separation showed best antimicrobial effect. In this research, the content of flavone total was 6.062 mg/g in Vitex negundo Linn. stem powder. We did HPLC analysis of the plants' ethanol extracts build a foundation for its later studies.Petroleum ether, acetic acid and n-butyl alcohol were used to extract the plants' ethanol extracts and its separate antimicrobial effects were studied. The separation and purification of acetic acid extract was investigated by using silica gel column chromatography and we separated into 7 parts. Part Fr4 showed best inhibitory effects to Staphylococcus aureus. Also, HPLC and its application in foods were investigated. The results showed that Fr4 contains multiple compounds. Fr4 and potassium sorbate were added into pork and milk to study its total plate counts while Fr4 showed good antimicrobial effects in the foods.