Spectral evidence for the oxidation of beta-hydroxybutyrate to acetoacetate: diminution of spectra by glucose and chloride.

ABSTRACT

Chemical oxidation of beta-hydroxybutyrate (beta-OHB) to acetoacetate (AcAc) has been carried out by a simple and new method employing potassium persulphate as an oxidising agent. Under the conditions of assay, beta-OHB (0.079-0.395 microM) was instantaneously oxidised to AcAc and the authenticity of the oxidised product was proved by absorption spectroscopy. A common absorption maxima at about 446 nm was observed in all the spectra recorded for the product (AcAc-complex) obtained after the oxidation of beta-OHB (0.079-0.395 microM) to AcAc followed by coupling with diazotized p-nitroaniline. This absorption maxima was almost equal to that obtained for AcAc-complex using AcAc as reference standard. It implies that AcAc formed by the chemical oxidation of beta-OHB is identically similar to the AcAc used as reference standard for the study. This fact was further strengthened when absorption spectra, recorded either individually or in combination (mixed-type), exhibited a single peak with a common absorption maxima at about 446 nm. Absorption spectra was found to be partially diminished by glucose (1.77 microM) and chloride (17.1 microM), while almost complete diminution of absorption spectra was observed at higher concentration of glucose (8.88 microM) and chloride (51.3 microM).