Morin is a flavonol having 2’,4’-dihydroxy group on B-ring identified especially in Moraceae plants. While morin is widely known, its glycosides are relatively rare. To the best of our knowledge, morin-3-O-glucoside (1) was first reported in 2008. However, the reported chemical shift values of 1 were unsatisfactory with those of the aglycone, morin, which is rather similar to quercetin-3-O-glucoside (2). Therefore, we prepared morin-3-O-glucoside (1) by microbial transformation of morin with Cunninghamella sp., and the NMR assignment was reinvestigated. The microbial culture also produced another compound (3). The NMR and MS analyses of 3 revealed it as a novel compound, morin-2’-O-glucoside (3).

In this study, the revision of the NMR assignment of morin-3-O-glucoside (1), and the preparation and structural elucidation of a novel compound, morin-2’-O-glucoside (3), were described.

Graphical abstract

中文翻译：

---

Morin-3-O-葡萄糖苷的 NMR 分配和 Morin-2'-O-葡萄糖苷的微生物生产的修订

桑色素是一种在 B 环上具有 2',4'-二羟基基团的黄酮醇，尤其在桑科植物中被鉴定。虽然桑色素广为人知，但其苷类却相对罕见。据我们所知，morin-3- O -glucoside ( 1 ) 于 2008 年首次被报道。然而，报道的1的化学位移值与苷元桑色素的化学位移值并不令人满意，后者与槲皮素-3 非常相似-O-葡萄糖苷( 2 )。因此，我们通过Cunninghamella sp.微生物转化桑色素制备了桑色素-3- O-葡萄糖苷( 1 ) ，并重新研究了NMR归属。微生物培养物还产生另一种化合物( 3 )。3的 NMR 和 MS 分析表明它是一种新化合物，morin-2'- O -glucoside ( 3 )。

在本研究中，描述了桑色素-3- O-葡萄糖苷( 1 )的NMR归属的修订，以及新化合物桑色素-2'- O-葡萄糖苷( 3 )的制备和结构阐明。

图形概要