Abstract
Flavonol glycosides, which are a kind of flavonoid, are generally known as antioxidative substances and
accumulated in various plant species. Recent studies showed that some flavonol glycosides possess anti-ice
nucleation activities (or supercooling-facilitating activities), which results in the depression of freezing
temperatures of the solutions in the presence of ice nucleating substances such as Erwinia ananas and silver
iodide. In this study, supercooling-facilitating activities in the crude extracts from leaves, which may include
supercooling-facilitating polyphenols, were compared among 65 plants (22 woody plants, 43 herbaceous
plants) by droplet freezing assay using E. ananas as an ice nucleator. Relatively high
supercooling-facilitating activities (>2˚C) were detected in the crude extracts from 14 plants. Since it is
expected that the application of crude extracts with relatively high supercooling-facilitating activities may
protect plant tissues from frost damages by ice-nucleating bacteria (Pseudomonas, Erwinia, etc.) on the
surface of the tissues at relatively high subzero temperatures (about -2 ~ -3˚C), further characterization were
examined using crude extract of Sasa senanensis with relatively high supercooling-facilitating activity. When
partial purification was examined, the HPLC recovered fraction which may include flavone glycosides,
which are also a kind of flavonoid, showed supercooing-facilitating activity.
