Methylation of Quercetin by Diazomethane and Hypoglycemic Activity of its Tetra-O-Methyl Ether
作者:E. R. Karimova、L. A. Baltina、L. V. Spirikhin、T. A. Sapozhnikova、S. F. Gabdrakhmanova、N. S. Makara
DOI:10.1007/s10600-020-03164-2
日期:2020.9
The tetra-O-methyl ether of quercetin (QU) 3 (54%), 3,7,4′-tri-O-methyl ether 4 (30%), and a previously unreported 3,7,3-tri-O-methyl ether of QU 5 (7%) were obtained via methylation of QU by an excess of diazomethane in dioxane. Their structures were established using 2D NMR (1H–1H COSY, 1H–1H NOESY, 1H–13C HSQC, 1H–13C HMBC). Tetra-O-methyl ether of QU 3 exhibited pronounced hypoglycemic activity
槲皮素(QU)3(54%),3,7,4'-三-O-甲基醚4(30%)和以前未报道的3,7,3-tri- O的四-O-甲基醚通过用过量的重氮甲烷在二恶烷中使QU甲基化,获得QU 5的-甲基醚(7%)。它们的结构使用2D NMR(1 H– 1 H COSY,1 H– 1 H NOESY,1 H– 13 C HSQC,1 H– 13 C HMBC)建立。四ø -甲基QU的醚3 具有明显的降血糖活性,与对照相比,大鼠的四氧嘧啶诱导的高血糖症减少了44.5%,活性是QU的2.7倍。