title: Biphasic effects of geranylgeraniol, teprenone, and phytol on the growth of Staphylococcus aureus.
abstract: We examined the antibacterial activities against Staphylococcus aureus of three diterpenes, namely, geranylgeraniol, teprenone, and phytol, by using a broth dilution with shaking method to identify the effects of diterpenes with long aliphatic carbon chains. We also performed time-kill assays and measured the leakage of K(+) ions from bacterial cells in response to these diterpenes. The diterpenes used inhibited the growth of S. aureus at concentrations of 0.15 microg/ml, as determined by damage to the cell membranes, and had clear bactericidal activity. However, the inhibitory effects of the diterpenes decreased when the concentration of each was raised above a certain level. The diterpenes tested in this study appeared to have both growth-inhibitory and growth-accelerating effects, and the net effect of each depended on its concentration.
authors.affiliation: Department of Microbiology, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan. inoue@ac.shoyaku.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Inoue
authors.forename: Toshiko
authors.initials: T
authors.lastname: Hada
authors.forename: Akiko
authors.initials: A
authors.lastname: Shiraishi
authors.forename: Kazuma
authors.initials: K
authors.lastname: Hirose
authors.forename: Hajime
authors.initials: H
authors.lastname: Hamashima
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D015169:Colony Count, Microbial; D003470:Culture Media; D004224:Diterpenes / Q000494:pharmacology*; D007202:Indicators and Reagents; D008826:Microbial Sensitivity Tests; D010836:Phytol / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D013329:Structure-Activity Relationship
chemical_list: D003470:Culture Media; D004224:Diterpenes; D007202:Indicators and Reagents; D010836:Phytol; C017338:geranylgeraniol; D011188:Potassium; C031049:geranylgeranylacetone