New dimeric compounds of avenanthramide phytoalexin in oats.
Avenanthramide B is an oat phytoalexin produced in response to pathogen attack and elicitation. We found the formation of new dimers (1-5) of avenanthramide B in elicited oat leaves. The dimers were synthesized by a reaction of peroxidase and avenanthramide B in the presence of hydrogen peroxide. The structures of 1-5 were determined by spectroscopic analyses, chemical derivatization, and 15N labeling. Compound 1 was a dehydrodimer of avenanthramide B with a bisbutane lactam skeleton, while 2-4 were monohydrated dehydrodimers with butane lactam structures. Compound 5 was also a monohydrated dehydrodimer but with a tetrahydrofuran structure. All the compounds were classified into lignanamides that were formed by an 8'-8' coupling reaction between two avenanthramide B units.
Okazaki
Yozo
Y
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Ishizuka
Akihiro
A
Ishihara
Atsushi
A
Nishioka
Takaaki
T
Iwamura
Hajime
H
D018554:Avena / Q000737:chemistry*; D019281:Dimerization; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D012717:Sesquiterpenes; D013729:Terpenes / Q000737:chemistry*; D062367:ortho-Aminobenzoates / Q000737:chemistry*; D000094162:Phytoalexins
D012717:Sesquiterpenes; D013729:Terpenes; D062367:ortho-Aminobenzoates; C514463:avenanthramide-2C; D000094162:Phytoalexins