Evaluation of the Antibacterial Activity of Rhapontigenin Produced fromRhapontin by Biotransformation Against Propionibacterium acnes

摘要

Biotransformation is often used to improve chemical activity.We evaluated the antimicrobial activity of rhapontigenin,converted from rhapontin after treatment with Pectinex.Rhapontigenin showed 4-16 times higher antimicrobialactivity than rhapontin. The activity was higher againstGram-positive strains than Gram-negative strains. Minimuminhibitory concentrations (MICs) of rhapontigenin, retinol,and five antibiotics were determined by the microbrothdilution method for antibiotic-sensitive and -resistantPropionibacterium acnes. We also investigated the in vitroantibacterial activity of rhapontigenin in combinationwith antibiotic against antibiotic-resistant P acnes. Theantibiotic combination effect against resistant P acneswas studied by the checkerboard method. The combinationformulations (rhapontigenin and clindamycin, retinol andclindamycin) showed synergistic effects on the inhibition ofthe growth of clindamycin-resistant P.acnes.It is predictablethat the combination of antibiotics with rhapontigeninis helpful to treat acne caused by antibiotic-resistantP acnes. The antibacterial activity of rhapontigenin wasenhanced by biotransformation.