Thermal degradation kinetics and pyrolysis GC-MS study of curcumin.

The objective of this work was to study kinetics of thermal degradation of curcumin in ambient-1023 K range and identify degradation products by GC-MS. No weight loss was observed up to ∼470 K and two major weight losses occurred beyond this. Sixteen degradation products were identified by GC-MS. Pharmacological properties, including LD, LC, gastrointestinal absorption, blood-brain barrier permeation and effect on cytochromes, of the products were calculated using standard software. The LD values indicated that the degradation products are more toxic than curcumin. All the decomposition products, except 2-methyl-6-(4-methylphenyl)-hept-2-en-4-one, have the potential to cross the blood-brain barrier that can affect brain functions. Twelve of the compounds showed the potential to inhibit the metabolism of xenobiotics and all the compounds appeared to be non-inhibitors of CYP2C9 and CYP3A4 in contrast to curcumin. Thus, this study suggests that the food materials containing curcumin when heated beyond 470 K will produce toxic substances.