Antioxidant properties of a new type of polyene, falconensone A and its derivatives.
Falconensones A and B are new type of yellow compound extracted from ascomycetous fungi, Emericella falconensis. Falconensone A p-bromophenylhydrazone and falconensone A dioxime are derivatives of falconensone A which have also been synthesized recently. The structural similarity of the falconensones to alpha-tocopherol (vitamin E) led us to investigate whether falconensones exhibit antioxidant activity. These studies found that falconensone A p-bromophenylhydrazone and falconensone A dioxime scavenge alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical in a 1 : 1 ratio in contrast to vitamin E, where a 1 : 2 ratio relative to DPPH radicals was observed. In addition, linoleic acid peroxidation initiated by hydroxyl radicals was diminished by falconensone A p-bromophenylhydrazone to a greater extent than by vitamin E, and lipid peroxidation in rat liver microsome was reduced by falconensone A dioxime and falconensone A p-bromophenylhydrazone. In contrast, falconensone A and falconensone B, the 4'-nor-methyl derivative of falconensone A, showed much lower activity or were inactive in scavenging radicals. These results suggest that falconensone A p-bromophenylhydrazone and falconensone A dioxime, may be useful new antioxidant agents, wherein the bromophenyl and hydroxy residues of falconensone A may be important for antioxidant activity. Based on these results, derivatives of falconensone A appear to be effective antioxidants that may have clinical utility for diseases treated with vitamin E.
Takahashi
N
N
Department of Health Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, Tokyo, Japan. t-noriko@rascal.hoshi.ac.jp
Tamagawa
K
K
Kawai
K
K
Fukui
T
T
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015764:Bepridil / Q000031:analogs & derivatives* / Q000378:metabolism; D001713:Biphenyl Compounds; D003517:Cyclopentanes / Q000494:pharmacology*; D007659:Ketones / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D010851:Picrates; D051381:Rats; D017207:Rats, Sprague-Dawley; D013481:Superoxides / Q000378:metabolism
D000975:Antioxidants; D001713:Biphenyl Compounds; D003517:Cyclopentanes; D007659:Ketones; D010851:Picrates; C414320:falconensone A; D013481:Superoxides; D015764:Bepridil; C004931:1,1-diphenyl-2-picrylhydrazyl