Phenolic Compounds from Twigs of Corylopsis coreana

Abstract

Corylopsis coreana Uyeki belongs to the Hamamelidaceae. The genus Corylopsis (Hamamelidaceae) consists of 31 genera and 144 species. C. coreana is a Korean endemic plant which defined as an endangered species. Seventeen compounds were isolated from methylene chloride fraction, ethyl acetate fraction and methanol fraction by using diverse chromatographic techniques on twigs of C. coreana. The structure was identified by physicochemical properties and spectroscopic data. Among the isolated compounds, compounds 1 - 3 are the first reported compounds to be reported as neolignan structures containing C6C3 which have not been studied previously. All the compounds were separated and identified as follows, Corynol (1) 3-methoxy-corynol (2) 3'-deoxy-corynol (3) bergenin (4) 11-O-galloyl bergenin (5) (−)-epicatechin (6) (−)-epicatechin 3-O-gallate (7) (−)-epigallocatechin gallate (8) 1,2,4,6-tetra-O-galloyl-β-D-glucose (9) 1,2,3,4,6-penta-O-galloyl-β-D-glucose (10) ellagic acid (11) benzoic acid (12) 3,4,5-trihydroxybenzoic acid (13) 3,5-dihydroxy-4-methoxybenzoic acid (14) 1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (15) methyl digallate (16) 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-β-D-glucopyranoside (17). Compounds 1 - 3 were neolignan, 4 - 5 were bergenin and its derivative, 6 - 8 were flavonoids, 9 - 10 were hydrolysis tannins, and 11 - 17 were phenolic compounds. Diabetes mellitus is a type of metabolic disease that causes persistent high blood sugar levels and causes various complications. Among them, Type 2 diabetes mellitus, known as non-insulin-independent diabetes, is the most common type of diabetes, and it can be alleviated by inhibiting the absorption of sugar. In particular, it can be treated by inhibiting α-glucosidase, an enzyme that helps digestion of sugars. In this study, seventeen compounds isolated from C. coreana were evaluated α-glucosidase inhibition and search for the compounds which showing strong inhibition in C. coreana.