New Antioxidative Phenolic Glycosides Isolated fromKokutoNon-centrifuged Cane Sugar

Abstract

Nine compounds, 3-hydroxy-4,5-dimethoxyphenyl-β-D-glucopyranoside (1),β-D-fructfuranosyl-α-D-(6-vanilloyl)-glucopyranoside (2), β-D-fructfuranosyl-α-D-(6-syringyl)-glucopyranoside (3), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)- 2-methoxyphenoxy]propyl-β-D-glucopyranoside(4), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3- hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy] propyl-β-D-glucopyranoside (5), dehydrodiconiferyl alcohol-9′-β-D-glucopyranoside (6), 4-[ethane-2-[3-(4-hydroxy-3-methoxyphenyl)-2-propen]oxy]-2,6-dimethoxyphenyl-β-D-glucopyranoside (7), 4-[ethane-2-[3-(4-hydroxy-3-methoxyphenyl)-2-propen]oxy]-2-methoxyphenyl-β-D-glucopyranoside (8), and 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy]propyl-β-D-glucopyranoside (9), were isolated from Kokuto non- centrifuged cane sugar. Their structures were elucidated by spectroscopic evidence, mainly based on the NMR technique. Among them, seven new glycosides were identified. The 2-deoxyribose oxidation method was used to measure their antioxidative activity. All of these compounds showed antioxidative activities.