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

Abstract

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

Ice segregation in the crown of winter cereals: Evidence for extraorgan and extratissue freezing

“…The significantly lower INA in the autoclaved treated leaf sheaths (Table ) could result from sucrose (Gusta et al, ), tannin (Wang et al, ), flavanol glycoside (Kasuga et al, ), and/or arabinoxylan (Olien, ) in the leachate. The INA of tissues in the autoclave/water treatment group was comparable with the INA of nonacclimated excised crowns.…”

“…The significantly lower INA in the autoclaved treated leaf sheaths (Table 5) could result from sucrose (Gusta et al, 2004), tannin (Wang et al, 2012), flavanol glycoside (Kasuga et al, 2008), and/or arabinoxylan (Olien, 1965) 3.6 | Three distinct freezing events in the cold-acclimated crown…”

Altitudinal and seasonal changes of phenolic compounds in Buxus sempervirens leaves and cuticles

“…3, Table 3). The increase in digalloylglucose derivative at the end of winter (March) might be related to its antioxidant properties [61] and/or to its capacity to inhibit ice nucleation of water, facilitating an adaptation to freezing temperatures, as suggested for the boreal hardwood Cercidiphyllum japonicum S.& Z. by Wang et al [62].…”

Characterization of Anti-Ice Nucleation Activity of the Extract from Coffee Refuse

“…Based our results, Kasuga et al 2008 found that some flavonol glycosides isolated from the xylem parenchyma cells had a high level of SFC activity. Furthermore, the hydrolyzable tannins in deep supercooling xylem cells in Cercidiphyllum japonicum exhibited the SFC activity like flavonol glycosides Wang et al, 2012 . As the cells of the katsura tree have been able to maintain a deep cooling state by accumulating some active compounds, we could predict that some compounds accumulated in other plants tissues or cells have similar activities.…”

“…Moreover, four kinds of flavonol glycosides with anti-ice nucleation activity have an important role in supercooling in the xylem parenchyma cells of katsura trees Cercidiphyllum japonicum Kasuga et al, 2008 . Furthermore, four kinds of hydrolysable gallotannins in the xylem parenchyma cells of katsura trees exhibited supercooling capabilities in the range of 1.5-4.5 , at a concentration of 1 mg/mL Wang D. et al, 2012 . The ability to avoid freezing like that of the katsura tree is due to low molecular weight compounds less than MW 500 like various polyphenols.…”