|Tilley, Michael - Mike|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/17/2004
Publication Date: 9/19/2004
Citation: Tilley, M., Benjamin, R.E., Tilley, K.A. 2004. Optimization of dityrosine standard synthesis. Abstract No. 220 in: 2004 AACC Annual Meeting Program Book. p.121. Meeting Abstract.
Technical Abstract: The oxidative coupling of tyrosine serves as a marker for protein oxidation and indicator of cellular damage. Dityrosine (DY) occurs in many biological systems formed by the action of peroxidases, reactive oxygen species/free radicals or ionizing radiation. DY has a functional role in the structure of extensible proteins and polymeric structures found in insect eggs, yeast spores, fibers such as silk and wool and may have a role in dough development and gluten film production. The synthesis of a standard is essential for analysis. Initial conditions for preparation of dityrosine, using 30 ppm potassium bromate (KBrO3), were based upon previous experiments utilized for crosslinking tyrosine and tyrosine containing peptides which resulted in a relatively low conversion to dityrosine. Optimization was performed for several variables, including concentrations of tyrosine and KBrO3), reaction temperature and reaction time. It was determined that the temperature (215 degrees C) and time (25 min) were optimal; however, the maximal synthesis of dityrosine was achieved from 10 mg tyrosine and 400 ppm KBrO3. The optimized method resulted in an average of 5.7 mg DY and purification involving two rounds of preparative and analytical HPLC resulted in 72% recovery (4.1 mg DY). This method will allow laboratories to synthesize stocks of this compound and shed light on a potential mechanism of (KBrO3).