Study of Semiconductor Photocatalysed Oxidation of ?-Hydroxybutyric Acid has Biological and Pharmaceutical Importance

Titanium dioxide (TiO2), as a semiconductor photocatalyst has been intensively investigated since Fujishima and Honda studied the photocatalytic splitting of water on TiO2 electrodes in 1972.1 Since then, many research efforts have been performed in understanding the fundamental processes and in enhancing the photocatalytic efficiency of TiO2. Titanium dioxide is when exposed to UV light, electrons in the uppermost valence band will jump to the conduction band and create conduction band electrons and valence band holes. In most instances, the valence band holes and conduction band electrons simply recombine liberating heat or light, a process known as recombination. Recombination is responsible for the low quantum yields.2-4 TiO2 also, due to its non-toxicity, long term photo stability, and high effectiveness, has been widely utilized in mineralizing toxic and non-biodegradable environmental contaminants as well as the novel organic synthesis. As a food additive16-18, TiO2 (titanium dioxide) is approved for use in various countries like EU, USA, Australia and New Zealand, it is listed by INS number 270 or E number E-270. The oxidized and polymeric derivatives of -hydroxybutyric acid occur widely in nature. In humans, D--hydroxybutyrate can be synthesized in the liver via the metabolism of fatty acids e. g. -hydroxy -methylbutyrate, and ketogenic amino acids through a series of reactions that metabolize these compounds into acetoacetate, which is the first ketone body that is produced in the fasting state.18 The concentration of -hydroxybutyrate in human blood plasma, as with other ketone bodies, increases through ketosis.19 The compound can be used as an energy source by the brain when blood glucose is low.20 Diabetic patients can have their ketone levels tested via urine or blood to indicate diabetic ketoacidosis. In alcoholic ketoacidosis, this ketone body is produced in greatest concentration. In the present part of study, it is planned to investigate photo-oxidation of tartronic acid (hydroxyl-propandioic acid) by semiconductor sensitized in visible light and the photoproduct was mesoxalic acid. It is therefore planed to investigate photo-oxidation of tartronic acid by semiconductors. Hence, this part of reported work may help to arouse the interdisciplinary interest about the side effects of photoproducts, where these are being used.