Three new 2-arylbenzofuran derivatives named mulberrofurans K, N, and O were isolated from the extract of the Chinese crude drug "Sang-Bai-Pi" (Japanese name "Sohakuhi"), the root bark of Morus sp. (Moraceae). The structures of mulberrofurans K, N and O were shown to be 1, 2, and 3, respectively, on the basis of spectral and chemical evidence. Mulberrofurans K and O are optically active and may be regarded biogenetically as Diels-Alder type adducts of chalcone derivatives and a dehydroprenyl-2-arylbenzofuran derivative. Furthermore, mulberrofuran K seems to be derived from the Diels-Alder type adduct by intramolecular ketalization.
Two novel 2-arylbenzofuran derivatives named mulberrofurans F and G (=albanol A), as well as albanol B (3), were isolated from the ethyl acetate extract of the root bark of cultivated mulberry tree (Japanese name "Roso, " a cultivated variety of Morus lhou KOIDZ.). The structures of mulberrofurans F and G were shown to be 1 and 2, respectively, on the basis of spectral and chemical evidence. Mulberrofurans F (1) and G (2) were derived from chalcomoracin (4) and mulberrofuran C (5), respectively, by photocyclization in acidic solution. The compounds (1, 2, and 3) are optically active and can be regarded biogenetically as variations of Diels-Alder type adducts of chalcone derivatives and a dehydroprenyl-2-arylbenzofuran derivative. Intravenous injection of mulberrofuran F (1), as well as G (2), caused a marked depressor effect in rabbit.
从栽培桑树(日本名称 "Roso",Morus lhou KOIDZ.的栽培品种)根皮的乙酸乙酯提取物中分离出了两种新型 2-芳基苯并呋喃衍生物,分别命名为桑白呋喃 F 和 G(=albanol A)以及 albanol B(3)。根据光谱和化学证据,桑白呋喃 F 和 G 的结构分别为 1 和 2。桑白呋喃 F(1)和 G(2)分别是在酸性溶液中通过光环化作用从氯鼠李素(4)和桑白呋喃 C(5)中得到的。这些化合物(1、2 和 3)具有光学活性,可被视为查耳酮衍生物和一种脱水丙烯基-2-芳基苯并呋喃衍生物的 Diels-Alder 型加合物的生物变体。静脉注射桑贝类呋喃 F(1)和 G(2)会对兔子产生明显的抑制作用。