Supercooling promoting agent

Abstract

During the investigation of the mechanism that cellular water in woody plants growing in cold districts keeps liquid state at low temperature, the inventors have studied to identify the causative substances. As the results, the present inventors identified supercooling promoting agents in woody plants. The supercooling ability of identified flavonoid glycoside and synthesized flavonoid glycoside with similar structure was tested. It was found that the supercooling promoting agent comprising these flavonoid glycosides enables to stably supercool bulk water at low temperature for long-term. The aqueous solution containing the supercooling promoting agent of the present invention is useful to store biological materials at low temperature.

1 - 8 . (canceled) 
     
     
         9 . A medication containing as a freeze control agent a flavonoid glycoside represented by Chemical Formula 1: 
       
         
           
           
               
               
           
         
         wherein 
         at least one of X 1  to X 4  is a sugar residue in which a hydrogen is removed from the hemiacetal hydroxyl group of monosaccharides or oligosaccharides and others are hydroxyl group or hydrogen atom; and R 1  to R 6 , which may be identical to or different from the other groups, are hydrogen atom, hydroxyl or methoxy group. 
       
     
     
         10 . The medication of  claim 9 , wherein the medication is prepared by freeze-drying. 
     
     
         11 . A food containing as a freeze control agent a flavonoid glycoside represented by Chemical Formula 1: 
       
         
           
           
               
               
           
         
         wherein 
         at least one of X 1  to X 4  is a sugar residue in which a hydrogen is removed from the hemiacetal hydroxyl group of monosaccharides or oligosaccharides and others are hydroxyl group or hydrogen atom; and R 1  to R 6 , which may be identical to or different from the other groups, are hydrogen atom, hydroxyl or methoxy group. 
       
     
     
         12 . The food of  claim 11 , wherein the food is prepared by freeze-drying. 
     
     
         13 . A method for controlling the freezing of a sample comprising:
 a) providing a sample containing a flavonoid glycoside represented by Chemical Formula 1:   
       
         
           
           
               
               
           
         
         
           wherein 
           at least one of X 1  to X 4  is a sugar residue in which a hydrogen is removed from the hemiacetal hydroxyl group of monosaccharides or oligosaccharides and others are hydroxyl group or hydrogen atom; and R 1  to R 6 , which may be identical to or different from the other groups, are hydrogen atom, hydroxyl or methoxy group; and 
         
         b) freeze-drying the sample. 
       
     
     
         14 . The method of  claim 13 , wherein the sample is a food. 
     
     
         15 . The method of  claim 13 , wherein the sample is a medication.