Presence of supercooling-facilitating (anti-ice nucleation) hydrolyzable tannins in deep supercooling xylem parenchyma cells in Cercidiphyllum japonicum

摘要: Xylem parenchyma cells (XPCs) in trees adapt to subzero temperatures by deep supercooling. Our previous study indicated the possibility of presence diverse kinds supercooling-facilitating (SCF; anti-ice nucleation) substances XPCs katsura tree (Cercidiphyllum japonicum), all which might have an important role supercooling XPCs. In study, a few SCF flavonol glycosides were identified. Thus, present we tried identify other tree. purified from xylem extracts silica gel column chromatography and Sephadex LH-20 chromatography. Then, four isolated identified UV, mass nuclear magnetic resonance analyses. The results showed that hydrolyzable gallotannins, 2,2′,5-tri-O-galloyl-α,β-d-hamamelose (trigalloyl Ham or kurigalin), 1,2,6-tri-O-galloyl-β-d-glucopyranoside Glc), 1,2,3,6-tetra-O-galloyl-β-d-glucopyranoside (tetragalloyl Glc) 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranoside (pentagalloyl exhibited capabilities range 1.5–4.5°C, at concentration 1 mg mL−1. These substances, including may contribute