Glycotechnology Laboratory

Mitsubishi Kagaku Institute of Life Sciences (MITILS)

Glycoconjugates existing on cell surfaces play important roles in development, immunity, and as ligands of various molecules. Our research objective is to investigate the chemical information contained in carbohydrates at the molecular level.

 
 

A proof of no anomerization in gas phase.


  1. Kanie, O. et al. Proc. Jpn Acad. Ser. B, 2009, 85, 204-215.

    Carbohydrates isomerizes in water. This is called anomerization. The ring of an hemiacetal opens to form an aldehyde in the presence of water and closes again forming a cyclic hemiacetal again. During the process, configuration of hydroxyl group at the anomeric position epimerize. This phenomenon was discovered by Dubrunfaut in 1846 about 50 year before Fisher received the Nobel prize.

    In the 19th century, sugar was one of the major merchandise that of course lead to profit. How SWEET! The sugar chemistry was active in connection to the economical situation. The polarimeter was used for the quality control purpose leading to the discovery of mutarotation caused by the anomerization process.


    We are investigating the detail chemical events taking place during the collision-induced dissociation (CID) reactions inside the mass spectrometer. We took a sodiated hemiacetal species and analyzed the behavior of the ion by the energy-resolved mass spectrometry in the stage-discriminated manner. We found that the sodiated hemiacetals do not anomerize in gas phase. This is fundamentally important as the basis of methods based on CID, because the type of ion species retain the anomeric configuration originated in their precursors thus one can get information about the configuration of a particular glycosidic linkage of oligosaccharide.


   Based on this finding, we showed that 1) mutarotation process can be monitored by mass spectrometry and 2) possibility in investigating a mechanism of glycosidase reactions (stereo-inversion vs. retention).



Mass spectrometry tells you “pureness” of an unknown oligosaccharide sample.

  1. Daikoku, S. et al. Carbohydr. Res. 2009, 344, 384-394.

We developed a novel method named as Stage-Discriminated Correlation) to reveal whether an totally unknown oligosaccharide (not limited to though) sample is “pure” or not. The basis of this is the individual chemical entities carry a characteristic activation energies, which can be observed by the energy-resolved mass spectrometry technique.



Stereospecific synthesis of hemiacetals in gas phase


Stereospecific generation of individual anomers of hemiacetals in gas phase: A first acomplishment


 Aminobutyl alpha- and beta-glycosides of lactose were individually subjected to collision-induced dissociation conditions to produce hemiacetal and pyrollidine. The generated hemiacetal was found to have the stereochemistry retained.


  1. 箇条書き項目Suzuki, K. et al. Anal. Chem., 2007, 79, 9022-9029.

  2. 箇条書き項目Shioiri, Y. et al. J. Mass Spectrom., 2008, 43, 1132-1139.


Blockbuster Paper


Papers with sum of number of citations during continuing five years exceeding 50 is called blockbuster paper.


  1. 箇条書き項目Carbohydrate Research, 1993, 243, 139-164.

  2.   8 times (1999-2006)

  3. 箇条書き項目Journal of the American Chemical Society, 1994, 116, 12073-12074.

  4.   10 times (2000-2009)

  5. 箇条書き項目Angewandte Chemie International Edition, 1996, 35, 2510-2512.

  6.   4 times (2002-2005)

  7. 箇条書き項目Angewandte Chemie International Edition, 1998, 37, 1524-1528.

  8.   3 times (2005-2007)

These papers have very long life that pleases me, but it takes at least six years to be evaluated. This is critical in the current evaluation system. People will be fired before it is acknowledged by others. We might try strategically publish short-live high impact papers as well. Well, what a hell. I matters but I do not care.


Chemoinformatics:

a missing view point


Structural information contained in a combinatorial library:


Combinatorial chemistry has been a focus area in connection with drug discovery in pharmaceutical companies. The definition of the term is the method of creating a series of compounds using multiple components, of which numbers greater than two, in a way of combination. A set of compounds created in this manner is called a combinatorial library. The term combinatorial chemistry is often used together with a following high-throughput screening, thus it is thought to speed-up a process of finding seed compounds through generation of diverse compounds and the screening.


Despite the advantage of the method, it is ignored that the structural information contained in the generated diverse compounds. Such information will be extremely useful in structural analysis, structure-activity relationship, etc. These are buried and the compounds found out to be non-active is dumped. In this manner, structurer-activity relationship is discussed only for the hit compounds where the definition of hit is generally biased. Chemoinformatics thus has a fundamental problem.


One may say “Well, what is wrong? This is the definition.” This is true, but it is also true that a value of structural information in the diversity is missed. We can find such value in synthesized compounds. The problem probably associates with the situation that the current science is so dependent on commercialism and so we do not get enough time for the research. Commercialism may be tolerated but the issue is the time. Is our efforts for tomorrow, day after tomorrow, or ... It seems we are allowed to do things for tomorrow only. This is the problem.



 
Detail of Research


Synthesis



Mass spectrometry





Gas phase Chemistry



Orthogonal coupling strategy



News


A list from PubMedhttp://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Search&db=PubMed&term=%22Kanie%20O%22%5BAuthor%5D


  1. 箇条書き項目Home Page renewal open


  1. 箇条書き項目Our institute will be closed in about one and half years. At this time, I thought about many things and decided to update our home page to remind myself feelings when I started research at the institute in 1999. Unfortunately however, I am experiencing an emergence of some antisocial thoughts in my mind. 


  1. 箇条書き項目It is quite curious that there is still budget maintaining garden despite the fact that we are forced to be out.


  1. 箇条書き項目Evaluation!?

  2. Total citation in 2006 was 100 by SCOPUS and thank who cited our articles.


  3. 箇条書き項目Cover of Chemistry An Asian Journal


  4. Cover story included as “Libraries not of books but of oligosaccharides have potentially important applications in medicine and the pharmaceutical industry. However, the building of these libraries is hindered by lengthy protocols and specific reaction conditions that cannot be applied generally. In response to these issues, Kanie and co-workers developed an efficient synthetic strategy based on a combination of solid-phase reaction and orthogonal glycosylation, in which monosaccharides are coupled to each other step by step to form anomeric combinations of oligosaccharides.”.


  5. We synthesized a library of linear trisaccharides where we decided to adopt stereo-non-selective glycosylation at each glycosylation site on acceptor molecules.


  6. -----Related articles-----

  7. Angew. Chem. Int. Ed., 2006, 45, 3851-3854.

  8. (German edition: Angew. Chem. 2006, 118, 3935-3938.)


 

July 30 2007 Cover, Vol. 85, Issue 31

C&EN NEWS

The Carbohydrate Connection

Hello and Goodbye

See inside for the detail.Photos_Mass.html

Thank you very much for visiting the site, however, we no longer work here any more. Actually, our institute came to an end of existence today on March 31, 2010.

Our brand new projects is going to be carried out at a new location at RIKEN institute.