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44216-B4
A Characterization of the Kinetics and Mechanisms of the Reaction of Ribose 5-Phosphate and Amino Acids

Roger K. Sandwick, Middlebury College

I.  Research Progress
             Over the past year, the efforts of four undergraduate researchers along with the) time I devoted to the project further advanced our understanding of the multiple reactions of R5P with biological amines in the Maillard series. We continued to define the kinetics of the early steps of the reaction and our work on kinetics is nearly complete.  Our attention this past year was placed primarily on identifying major reaction products, including reactive oxygen species (ROS).  One primary reaction product of interest is the molecule 4-hydroxy-5-methyl-3(2H)-furanone (HMF), a molecule desired commercially for its aroma/browning characteristics in baked foods and, more recently, as a possible fuel precursor.  The molecule is formed through a dicarbonyl from D-ribose but the Maillard reaction path from R5P is not well understood.   Our findings indicate a need for a-amino acids (as opposed to simple amines like n-butylamine) in the production of HMF suggesting some type of additional activation is necessary.  This research has directly led to an investigation of HMF from R5P with intent to define kinetics and reaction paths.  
             The other main area of attention in the past year has been the elucidation of the role ROS play in the R5P reaction path.   During the past year we used the protein myoglobin both as a source of the amine in the Maillard reaction and to identify formation of ROS in the reaction.  This work has resulted in a submitted manuscript currently being considered for publication by the journal Carbohydrate Research.  The co-authors of this manuscript are Middlebury undergraduates Andrew Livermore, Andrew Harris, Magdalena Bokiej, and Anne Onishi.  This work was also presented as a poster at the IX International Symposium on the Maillard Reaction in early September, 2007 in Munich, Germany. 
              Future Research:   A remaining goal is to investigate how the attached phosphate stimulates the R5P Maillard reaction.  While some information was gleaned from the research performed in the last two years, the question of the role of the phosphate in catalysis of the R5P reaction needs a model that can distinguish between various catalytic effects.  Our plans are to synthesize both the methyl ester (to the phosphate) form and the 5-deoxy form of R5P and then perform comparable kinetics studies of these modified sugars.  
II. Intellectual Development of Undergraduate Researchers
             The project impacted the development of four Middlebury undergraduates during the 2007 – 2008 year.   Andrew Livermore completed his thesis work with an investigation of R5P and myoglobin. He has since started medical school at the University of Wisconsin in Fall, 2008.  Mr. Mohammed Almzayyen, a MBB major, and Ms. Anne Onishi, a Biochemistry major, are currently seniors working on senior thesis projects in the Maillard area.  Ms. Onishi has applied for entrance into medical school for Fall, 2009 while Mr. Almzayyen is still deciding his future path in science.  Ms. Risa Roppongi, a Biochemistry major, performed a Maillard research project in spring, 2008 and will continue this year.  Her hopes are to pursue a Masters in Public Health following graduation.
III. Professional Growth of the PI
             The increased research interaction with Middlebury students provided by this grant resulted in the growth of the PI as an undergraduate mentor.  The experiences add to the ability of the PI to serve as an advisor to the undergraduates in their decisions towards future careers as scientists. The support has also aided him professionally to become an active scholar in this line of Maillard research.  The submitted manuscript to Carbohydrate Research will hopefully lead to another publication by the PI, thus strengthening his reputation in the field.  In early September, 2007, the PI presented a poster at the 9^th International Symposium on the Maillard Reaction (held in Munich, Germany), an opportunity that allowed him to gain insight into the most recent advances into Maillard chemistry. 
IV. Financial Progress
             One-third of the total grant ($16,625) was designated for efforts carried out during the second year.  The requested stipend for the PI for summer, 2008 was not used as the PI drew maximum salary from other funding sources.  Instead, a portion of this allotment will be used to cover a stipend for a second undergraduate researcher in the upcoming year. The student stipends were also not used (two student stipends were drawn from year one) as students working on this project received stipend coverage from on-campus and off-campus funds.  The student stipends will be postponed for use in summer, 2009.  Inadvertently, we forgot to add the student benefits ($740) in last year’s report and have therefore added them in this year’s budget. A $1155 allotment for travel was employed to partially cover the PI’s expenses to the Maillard Symposium in Germany in Sept. 2007.  The PI hopes to use remaining travel funds to attend the Maillard Symposium in Australia in 2009.

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