海南黄花梨中1个新的异黄酮类化合物及其酪氨酸酶抑制活性

A new isoflavone from Dalbergia odorifera and inhibitory activity of its tyrosinase

采用加热回流提取、溶剂萃取、重结晶及正相硅胶、Sephadex LH-20、MCI、HPLC等多种色谱技术,对海南黄花梨干燥枝叶化学成分进行研究,分离得到12个黄酮类化合物。结合NMR、MS等波谱方法对分离得到的化合物进行结构鉴定,分别为6,7,8-三甲氧基-5,4′-二羟基异黄酮(1)、美迪紫檀素(2)、7,2′-二羟基-4′-甲氧基-异黄烷醇(3)、鹰嘴豆芽素A(4)、樱黄素(5)、染料木素(6)、红车轴草素(7)、3-(4-hydroxyphenyl)-6-isopentenyl-7-methoxy-4H-chromen-4-one(8)、鸢尾黄素(9)、尼泊尔鸢尾异黄酮(10)、维斯体素(11)和芒柄花黄素(12)。其中化合物1为新的异黄酮类化合物,化合物8为首次从海南黄花梨中分离得到。对分离得到的化合物进行体外酪氨酸酶抑制活性测试显示化合物1~3对酪氨酸酶有抑制作用,在1.0 mmol·L的浓度下,抑制率分别为35.58%、38.63%、51.34%。

Twelve flavonoids were isolated and purified from the ethyl acetate fraction of 95%ethanol extract of Dalbergia odorifera by heat reflux extraction,solvent extraction,recrystallization,normal phase silica gel,Sephadex LH-20,MCI gel and HPLC methods.The structures were identified with multiple spectroscopic methods,including 1 D-NMR,2 D-NMR and MS.The compounds were identified as 6,7,8-trimethoxy-5,4′-dihydroxy isoflavone(1),medicarpin(2),7,2′-dihydroxy-4′-methoxy-isoflavanol(3),biochanin A(4),prunetin(5),genistein(6),pratensein(7),3-(4-hydroxyphenyl)-6-isopentenyl-7-methoxy-4H-chromen-4-one(8),tectorigenin(9),irisolidone(10),vestitol(11),and formononetin(12).Compound 1 was a new isoflavone,and compound 8 was isolated from D.odorifera for the first time.The results showed that compounds 1-3 had inhibitory effects on tyrosinase,with inhibition rates of 35.58%,38.63%and 51.34%at the concentration of 1.0 mmol·L,respectively.