Effect of Different Chemical Species on the Behavior of Tyrosine in a Typical BR Oscillatory Chemical Reaction

Effect on the behavior of Tyrosine through a malonic acid (MA) based Briggs‐Rauscher (BR) oscillatory system was studied in order to understand the mechanistic details of thyroid metabolism in vitro, specifically the iodination of tyrosine. It was observed that the present BR system employing tyrosine as a main additive and malonic acid as substrate provides an example of entrainment oscillations, in which malonic acid is responsible for oscillations and in presence of tyrosine, the system showed different oscillatory behavior. The effects of various other chemical species such as SeO2, KSCN, KNO3, KBr and Fe(III) on the tyrosine in this malonic acid based BR system are studied. The study was supported by UV‐Visible spectrophotometry to study the interactions of these chemical species with Dushmann reaction, which is one of the important reaction steps in BR reaction mechanism, in order to investigate the key factors responsible for tyrosine iodination responsible for thyroxin formation. Needless to mention that, all the aforesaid chemical species have due role in normal thyroid metabolism in vivo and as such, the present BR system containing tyrosine as main (first) additive can help in understanding of thyroid metabolism. Different chemical species have significantly altered the mechanism of iodination of tyrosine causing hyper or hypothyroidism. SeO2, Fe(III) increased the production of iodine, thereby, increasing the tendency of monoiodotyrosine formation, leading to hyper‐thyroid behavior. Whereas, KSCN and KBr reduced the production of iodine in the BR system in vitro and as such is responsible for a hypo‐thyroid behavior.