title: Effect of substituents at phenyl group of 7,7'-dioxo-9,9'-epoxylignane on antifungal activity.
abstract: Using 21 newly synthesized 7,7'-dioxo-9,9'-epoxylignane derivatives having a modified 7-phenyl group, we examined the relationship between their structure and antifungal activity against plant pathogens such as Bipolaris oryzae to determine the effects of various substituents on the antifungal activity. Compared with the lead compound having a 4-OH-3-CH(3)O-phenyl moiety, several analogs showed higher antifungal activity against B. oryzae, including the compound having an unsubstituted phenyl group and those having either of the following phenyl substituents: 2-OH, 4-CH(3)O, 4-C(2)H(5)O, 4-n-C(3)H(7)O, 4-n-C(4)H(9)O, 4-CF(3)O, 4-C(2)H(5), or 4-Cl. On the other hand, the activity of compounds having a branched substituent, such as 4-i-C(3)H(7)O or 4-i-C(3)H(7), on the 7-phenyl group or a multi-substituted phenyl group was equipotent or inferior to that of the lead compound. These results as well as correlations between the antifungal activity of the test compounds and the physicochemical parameters of the varied substituents suggest that the position of substitution on the 7-phenyl group and the incorporation of substituents with optimal physicochemical properties are important for exerting the antifungal activity.
authors.affiliation: Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nishiwaki
authors.forename: Maya
authors.initials: M
authors.lastname: Ouchi
authors.forename: Junko
authors.initials: J
authors.lastname: Matsugi
authors.forename: Koichi
authors.initials: K
authors.lastname: Akiyama
authors.forename: Takuya
authors.initials: T
authors.lastname: Sugahara
authors.forename: Taro
authors.initials: T
authors.lastname: Kishida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamauchi
mesh_terms: D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects*; D017705:Lignans / Q000737:chemistry* / Q000494:pharmacology*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: C579015:7,7'-dioxo-9,9'-epoxylignane; D000935:Antifungal Agents; D017705:Lignans