6-{[5-hydroxy-2-({5-hydroxy-2-[(5-hydroxy-2-{[3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl]methyl}-3-(hydroxymethyl)-6-methylpyridin-4-yl)methyl]-3-(hydroxymethyl)-6-methylpyridin-4-yl}methyl)-3-(hydroxymethyl)-6-methylpyridin-4-yl]methyl}-4,5-bis(hydroxymethyl)-2-methylpyridin-3-ol