Antimicrobial Activities of Hydroxybiphenyl Derivatives

It has been elucidated that magnolol and honokiol, isolated from the stem bark of Magnolia obovata, had potent antibacterial activity against a cariogenic bacterium Streptococcus mutans. They also show a significant antibacterial activity against Bacillus anthracis, which causes malignant pustule and woolsorter disease in human. Some hydroxybiphenyl derivatives are synthesized from starting materials, phenylphenols and biphenols by means of Claisen's rearrangement and Elb's method to develop more potent antibacterial chemicals and to investigate the structure-activity relationships. The introduction of allyl groups to the aromatic rings of starting materials shows increase of antibacterial activities, but the number and positions of them do not effect their activities. Furthermore, the introduction of hydroxy group to aromatic rings also increases the activity.