Oxidative Transformation of Demethoxy- and Bisdemethoxycurcumin: Products, Mechanism of Formation, and Poisoning of Human Topoisomerase IIα.

ABSTRACT: Extracts from the rhizome of the turmeric plant are widely consumed as anti-inflammatory dietary supplements. Turmeric extract contains the three curcuminoids, curcumin (≈80% relative abundance), demethoxycurcumin (DMC; ≈15%), and bisdemethoxycurcumin (BDMC; ≈5%). A distinct feature of pure curcumin is its instability at physiological pH, resulting in rapid autoxidation to a bicyclopentadione within 10-15 min. Here, we describe oxidative transformation of turmeric extract, DMC, and BDMC and the identification of their oxidation products using LC-MS and NMR analyses. DMC autoxidized over the course of 24 h to the expected bicyclopentadione diastereomers. BDMC was resistant to autoxidation, and oxidative transformation required catalysis by horseradish peroxidase and H2O2 or potassium ferric

SUBMITTER: Gordon ON 

PROVIDER: S-EPMC4437832 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature