Surface enhanced Raman scattering based reaction monitoring of in vitro decyclization of creatinine → creatine
in: RSC Advances (2016)
Creatinine → Creatine decyclization is an important reaction where we obtain a beneficial compound from a toxic substance. Decyclization of creatinine at basic pH has been monitored in vitro by time series surface enhanced Raman scattering (SERS) using silver island film. NH2 scissoring, C=N and C=O stretching modes of creatinine serve as Raman markers for monitoring the decyclization reaction. Transition state calculations using DFT have revealed the path of formation of creatine by the cleavage of endocyclic C=N bond of creatinine. The Raman signatures of ring opening are clearly observed after 120 min at pH 8 and further increasing the pH increases the reaction rate even more as the signatures are observed after 60 and 30 min at pH 10 and 12 respectively. However, the reversibility of the reaction is more prominent at higher pH. Therefore pH 8 is the most favorable amongst the three pH values for the decyclization reaction to be stable at room temperature. The proper understanding of this reaction where a toxic substance is converted to a beneficial compound is expected to open scope of extensive further research.