Studies on antibacterial activity of flavonoids and diarylheptanoids from Alpinia katsumadai

The antibacterial activity of four compounds of flavonoids and diarylheptanoids from Alpinia katsumadai Hayata were studied by the tube double dilution method.The results indicated that the minimal inhibitory concentration(MIC) of trans,trans-1,7-diphenyl-4,6-heptadien-3-one and alpinetin against Helicobacter pylori reached to 1.25 μg·mL~(-1),which showed strong effects of antibacterial activity.MIC of cardamomin and pinocembrin against H.pylori were 2.56 and 0.32 mg·mL~(-1) respectively.The MIC of trans,trans-1,7-diphenyl-4,6-heptadien-3-one and cardamomin against Staphylococcus aureus Rosenbach,S.epidermidis(Winslow et Winshlow) Evans,Escherichia coli(Migula) Castellani et Chalmers,etc.reached to 0.208-1.667 and 0.122-1.955 mg·mL~(-1) respectively,which showed strong effects of antibacterial activity,and that of pinocembrin and alpinetin against S.aureus,S.epidermidis,E.coli,etc.reachedto1.275-2.550and1.925-3.850 mg·mL~(-1) respectively.It is concluded that cardamomin,pinocembrin,trans,trans-1,7-diphenyl-4,6-heptadien-3-one and alpinetin were the antibacterial activity components of Alpinia katsumadai seeds.