Jang JunPil, Na Minkyun, Thuong Phuong Thien, Njamen Dieudonné, Mbafor Joseph Tanyi, Fomum Zacharias Tanee, Woo Eun-Rhan, Oh Won Keun
Korea Research Institute of Bioscience and Biotechnology, Korea.
Chem Pharm Bull (Tokyo). 2008 Jan;56(1):85-8. doi: 10.1248/cpb.56.85.
Phytochemical study on an EtOAc-soluble extract of the root bark of Erythrina mildbraedii resulted in the isolation of six prenylated flavonoids 1-6. Based on physicochemical and spectroscopic analyses, their structures were determined to be new natural products licoflavanone-4'-O-methyl ether (1), 2',7-dihydroxy-4'-methoxy-5'-(3-methylbut-2-enyl)isoflavone (2), and (3R)-2',7-dihydroxy-3'-(3-methylbut-2-enyl)-2''',2'''-dimethylpyrano[5''',6''' :4',5']isoflavan (3), along with three known compounds erythrinin B (4), abyssinin II (5), and parvisoflavone B (6). All the isolates, except for compound 4, inhibited PTP1B activity in vitro with IC(50) values ranging from 5.3 to 42.6 microM. This result further suggests that the prenyl group on the B ring of flavonoids plays an important role in suppressing the enzyme PTP1B.
对 Erythrina mildbraedii 根皮乙酸乙酯可溶提取物进行的植物化学研究，从中分离出了六种异戊烯基黄酮类化合物1 - 6。基于物理化学和光谱分析，确定它们的结构为新的天然产物甘草黄酮醇 - 4'-O - 甲基醚（1）、2',7 - 二羟基 - 4'- 甲氧基 - 5' - (3 - 甲基丁 - 2 - 烯基)异黄酮（2）和(3R) - 2',7 - 二羟基 - 3' - (3 - 甲基丁 - 2 - 烯基) - 2''',2'''- 二甲基吡喃并[5''',6''' :4',5']异黄酮（3），以及三种已知化合物刺桐宁B（4）、深渊菌素II（5）和小叶黄酮B（6）。除化合物4外，所有分离物均在体外抑制蛋白酪氨酸磷酸酶1B（PTP1B）的活性，IC(50)值范围为5.3至42.6微摩尔。该结果进一步表明黄酮类化合物B环上的异戊烯基在抑制PTP1B酶方面起着重要作用。
