title: Synthesis of 3-substituted isocoumarins and their inhibitory effects on degranulation of RBL-2H3 cells induced by antigen.
abstract: Eleven 3-substituted isocoumarins and a benzylidenephthalide were synthesized through thermal cyclization reaction of delta- and gamma-ketoamides, respectively. Subsequent deprotection of the hydroxyl groups of the resulting isocoumarin and benzylidenephthalide compounds afforded thunberginols A, B, and F, respectively, which originated from the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO. The synthesized isocoumarins and thunberginols were evaluated for their anti-allergic activity, in which thunberginol B exhibited the highest inhibitory potency on the degranulation of RBL-2H3 cells induced by antigen. Structure-activity relationship studies were carried out to determine the necessary substituents on the 3-phenylisocoumarin skeleton for inhibitory activity.
authors.affiliation: Department of Functional Molecular Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Kurume
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kamata
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamashita
authors.forename: Qilong
authors.initials: Q
authors.lastname: Wang
authors.forename: Hisashi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kawasaki
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Ohta