88(PA3-8) ジンチョウゲより得られる新ビフラボノイド類の構造(ポスター発表の部)

抄録

We investigated the root and the bark of Daphne odora Thunb. in order to study its phenolics, and isolated four new biflavonoids, daphnodorin A (1), daphnodorin B (2), daphnodorin C (3) and daphnodorin D (4) together with seven known compounds. The plane structures of 1 and 2 were established as furanoflavan type's biflavonoid by chemical and spectral evidence. The absolute configurations of 1 and 2 were assigned as C-2(S) and C-2(R), C-3(S) on the basis of their CD spectra and the X-ray analysis of a pentamethyl ether of 1 (5). The plane structure of 3 was determined to be spirobiflavonoid by chemical and spectral means. The absolute configuration of 3 was confirmed as C-2(S), C-2"(S) and C-3"(S) by chemical transformatin of 3 into 1 and the X-ray analysis of 3. Compound 4 was confirmed to be a mixture of atropisomers of flavan^<8_3"> flavon by chemical and spectral evidences. Further, it was proved that 3 was transformed into 1, 4 and a linear form of 3 on the acidic or basic conditions.